ARTICLE | doi:10.20944/preprints202010.0471.v1
Subject: Engineering, Automotive Engineering Keywords: Battery energy storage system (BESS); method of fault positions; renewable energy; transient stability; voltage sags
Online: 23 October 2020 (08:49:46 CEST)
Voltage sags can cause the interruption of power supply and can negatively affect operations of customers. In this paper, the authors study the impact of battery energy storage systems (BESS) on voltage sags. A stochastic method of fault positions is used. Faults of various types are simulated and voltages are recorded. Firstly, with the BESS integrated into the network, there are higher residual voltages, fewer voltage sags and less expected critical voltage loss. Secondly, if the BESS converter power factor is reduced, recorded residual voltages are higher, voltage sags are fewer, and the number of expected critical voltage sags is lower. Finally, when three BESS converter control modes, namely constant voltage, constant power factor, and constant reactive power, were assessed, results showed similar voltage sag performances for constant power factor and constant reactive power modes. Furthermore, operating in constant voltage control outperformed the other two modes as it resulted in higher residual voltages, a lower number of voltage sags, and fewer expected critical voltage sags. The paper has demonstrated that the BESS can improve voltage sag performance. In addition, the power factor of the BESS converter and the mode of operation of the converter can influence the magnitude of the voltage sag performance improvement.
ARTICLE | doi:10.20944/preprints201705.0160.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: active power control; battery charging; dual active bridge; energy storage system; hardware-in-loop
Online: 22 May 2017 (07:43:32 CEST)
Grid energy storage system for PV Applications is connected with three different power sources i.e. PV Array, Battery and the Grid. It is advisable to have Isolation between these three different sources to provide safety for the equipment. The configuration proposed in this paper provides the complete isolation between the three sources. A Power Balancing Control (PBC) for this configuration is proposed to operate the system in three different modes of operation. Control of a dual active bridge (DAB) based battery charger which provides a galvanic isolation between batteries and other sources is explained briefly. Various modes of operation of a Grid energy storage system are also presented in this paper. Hardware-In-Loop (HIL) Simulation is carried out to check the performance of the system and the PBC algorithm. Power circuit (comprises of inverter, dual active bridge based battery charger, grid, PV cell, batteries, contactors and switches) is simulated and the controller hardware and user interface panel are connected as HIL with the simulated power circuit through Real Time Digital Simulator (RTDS). HIL simulation results are presented to explain the control operation, steady state performance in different modes of operation and the dynamic response of the system.
REVIEW | doi:10.20944/preprints202105.0507.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Energy storage system, photovoltaic systems, PV-battery, regulatory issues, energy management.
Online: 21 May 2021 (09:29:36 CEST)
Integration of battery energy storage in photovoltaic (PV) systems can reduce the electricity costs and provide desirable flexibility and reliability to these systems decreasing renewable energy fluctuations. This paper presents a review of the PV-battery application in Brazil, highlighting the challenges and prospects based on the state-of-art. A PV-battery systems description is presented in this work, as well as the most applied battery technology and its comparison. The paper also describes the set of applications such as voltage and frequency regulation, renewable energy integration, power quality, etc. In the Brazilian scenario, there are applications of PV-battery systems, most of them part of research and development projects (R&D’s), and some real cases are shown, including its goals, applied equipment, operation modes, strategies, and perspectives. Additionally, this work evaluates the Brazilian scenario regarding the energy storage systems implementation challenges, such as regulatory barriers, business models, and opportunities for R&D in the energy market. In conclusion, it is need develop proper regulatory models to expand PV-battery systems and make them visible to the agents in the electricity sector.
ARTICLE | doi:10.20944/preprints201609.0072.v1
Subject: Chemistry, Electrochemistry Keywords: Pb-acid batteries, electrolyte additives, battery energy capacity, electrolyte additive concentration
Online: 20 September 2016 (15:39:49 CEST)
The paper presents a method to assess the effect of electrolyte additives on the energy capacity of Pb-acid batteries. The method applies to any chemically unreactive additive, including suspensions and gels. The approach is thermodynamically based and it leads to the definition of a region of admissible concentrations –the battery’s admissible range– where the battery can undergo an indefinite number of charge/discharge cycles without suffering permanent damage. An experimental procedure to determine this range is presented. The obtained results provide a way to assess the potential of electrolyte additives to improve the energy capacity of Pb-acid batteries. The same results also provide a means to determine the additive concentration that produces the maximum energy capacity increase of the battery. The paper closes with an example of application of the proposed approach to a practical case.
ARTICLE | doi:10.20944/preprints201711.0069.v1
Subject: Keywords: game theory; smart grid; energy storage; battery modelling; demand-side management; load-shaping
Online: 10 November 2017 (10:08:01 CET)
Energy storage systems will play a key role for individual users in the future smart grid. They serve two purposes: (i) handling the intermittent nature of renewable energy resources for a more reliable and efficient system, and (ii) preventing the impact of blackouts on users and allowing for more independence from the grid, while saving money through load-shifting. In this paper we investigate the latter scenario by looking at a neighbourhood of 25 households whose demand is satisfied by one utility company. Assuming the users possess lithium-ion batteries, we answer the question of how each household can make the best use of their individual storage system given a real-time pricing policy. To this end, each user is modelled as a player of a non-cooperative scheduling game. The novelty of the game lies in the advanced battery model, which incorporates charging and discharging characteristics of lithium-ion batteries. The action set for each player comprises day-ahead schedules of their respective battery usage. We analyse different user behavior and are able to obtain a realistic and applicable understanding of the potential of these systems. As a result, we show the correlation between the efficiency of the battery and the outcome of the game.
ARTICLE | doi:10.20944/preprints201701.0089.v1
Subject: Materials Science, Nanotechnology Keywords: MoS2; composite; anode; low cost; Li-ion battery
Online: 19 January 2017 (11:08:29 CET)
A low-cost bio-mass-derived carbon substrate has been employed to synthesize MoS2@carbon composites through a hydrothermal method. Carbon fibers derived from natural cotton provide a three-dimensional and open framework for the uniform growth of MoS2 nanosheets, thus constructing hierarchically coaxial architecture. The unique structure could synergistically benefit fast Li-ion and electron transport from the conductive carbon scaffold and porous MoS2 nanostructures. As a result, the MoS2@carbon composites, when served as anodes for Li-ion batteries, exhibit a high reversible specific capacity of 820 mAh g-1, high-rate capability (457 mAh g-1 at 2 A g-1), and excellent cycling stability. The superior electrochemical performance makes the MoS2@carbon composites to be low-cost and promising anode materials for Li-ion batteries.
REVIEW | doi:10.20944/preprints202002.0112.v1
Online: 9 February 2020 (17:11:44 CET)
The ever-rising demands for energy dense electrochemical storage systems have been driving interests in beyond Li-ion batteries such as those based on lithium and magnesium metals. These high energy density batteries suffer from several challenges, several of which stem from the flammability/volatility of the electrolytes and/or instability of the electrolyte with either the negative, positive electrode or both. Recently, hydride-based electrolytes have been paving a path towards overcoming these issues. Namely, highly performing solid state electrolytes have been reported and several key challenges in multivalent batteries were overcome. In this review, the classes of hydride-based electrolytes reported for energy dense batteries are discussed. Future perspectives are presented to guide research directions in this field.
ARTICLE | doi:10.20944/preprints202108.0264.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: solar photovoltaic (PV); wind turbine coupled to permanent synchronous generator (WT-PMSG); battery energy storage (BESS); maximum power point tracking (MPPT); DC/DC converters
Online: 11 August 2021 (15:10:26 CEST)
This paper presents a microgrid distributed energy resources (DERs) for a rural standalone system. It is made up of solar photovoltaic (solar PV) system, battery energy storage system (BESS), and wind turbine coupled to permanent magnet synchronous generator (WT-PMSG). The DERs are controlled by maximum power point tracking (MPPT) based proportional intergral (PI) controllers for both maximum power tracking and error feedback compensation. The MPPT uses the perturb and observe (P&O) algorithm for tracking the maximum power point of the DERs. The PI gains are tuned using the Ziegler-Nichol’s method. The developed system was built and simulated in MATLAB/Simulink under two conditions - constant load, and step load changes. The controllers enabled the BESS to charge even during conditions of varying load and other environmental factors such as change of irradiance and wind speed. The reference was tracked very well by the output voltage of the DC grid. This is a useful research for electrifying the rural islanded areas, too far from the grid.
ARTICLE | doi:10.20944/preprints202101.0371.v1
Subject: Engineering, Automotive Engineering Keywords: Battery; Supercapacitor; Hybrid power system; Optimal control; DC/DC converter; Energy management strategy
Online: 19 January 2021 (10:56:21 CET)
This paper aims at presenting an energy management strategy (EMS) based upon optimal control theory for a battery-supercapacitor hybrid power system. The hybrid power system consists of a Lithium-ion battery and a supercapacitor with associated bidirectional DC/DC converters. The proposed EMS aims at computing adaptive gains using salp swarm algorithm and load following control technique to assign the power reference for both the supercapacitor and the battery while achieving optimal performance and stable voltage. The DC-DC converter model is derived utilizing the first-principles method and compute the required gains to achieve the desired power. The fact that the developed algorithm takes disturbances into account increases the power ele-ments’ life expectancies and supplies the power system with the required power
ARTICLE | doi:10.20944/preprints202207.0299.v1
Subject: Engineering, Energy & Fuel Technology Keywords: battery thermal management; biodiesel fuel; hybrid vehicle; Li-ion battery; cooling technology
Online: 20 July 2022 (09:01:45 CEST)
This paper focuses on the comparative analysis of lithium-ion batteries (LIB) thermal management with aim to maintain working temperature in the range 15 ℃ – 35 ℃. This is to prevent thermal runaway and high temperature gradients. The proposed approach is to employ the biodiesel, situated inside the diesel/LIB powered hybrid electric vehicle, to supply as fuel and coolant. A 3S2P LIB module is simulated using Ansys-Fluent CFD software tool. The system without a coolant shows that LIB has exceeded the optimum maximum temperature, which leads to shortened life-cycle and poor performance. Four fatty acid methyl ester biodiesels are used as coolants, namely palm, karanja, jatropha, and mahua oils. When compared with conventional methods of cooling, using air and 3M Novec liquid, the palm biodiesel coolant proves to be the best option to maintain LIB temperature within the optimum working range. With the use of palm biodiesel, the system is estimated to lightweight the BTMS by 43%, compared to the case when 3M Novec is used to maintain the same temperature range.
REVIEW | doi:10.20944/preprints202205.0303.v1
Subject: Chemistry, Electrochemistry Keywords: boron; lithium battery; lithium-ion batteries; cathode; anode; electrolyte; battery thermal management system (BTMS); battery performance
Online: 23 May 2022 (10:57:06 CEST)
Lithium batteries and an increasing focus on CO2 reduction have become an integral part of daily life and business for many people. Boron and boron compounds have been widely studied together in the history and development of lithium batteries. With a broad examination of battery components and systems but a boron-centric approach to raw materials, this review seeks to summarize past and recent studies on the following: which boron compounds are studied in lithium battery, in which parts of lithium batteries, what improvements are offered for battery performance, and what improvement mechanisms can be explained. The uniqueness of boron and its extensive application beyond batteries contextualizes the interesting similarity with studies on batteries. The paper predominantly focuses on lithium-ion batteries (LIBs) but also mentions other lithium batteries. At the end, the article aims to predict prospective trends for future studies that may lead to the successful and extensive use of boron compounds on a commercial scale.
ARTICLE | doi:10.20944/preprints201612.0029.v1
Subject: Engineering, Automotive Engineering Keywords: electric vehicle; battery heat generation; battery degradation; vehicle operation cost; preheating target temperature; heating system
Online: 6 December 2016 (07:46:46 CET)
This paper presents an optimized energy management strategy for Li-ion power batteries used on electric vehicles (EVs) at low temperatures. Under low-temperature environments, EVs suffer a sharp driving range loss resulted from the energy and power capability reduction of the battery. Simultaneously, because of Li plating, battery degradation becomes an increasing concern as temperature drops. All these factors could greatly increase the total vehicle operation cost. Prior to battery charging and vehicle operating, preheating battery to a battery-friendly temperature is an approach to promote energy utilization and reduce total cost. Based on the proposed LiFePO4 battery model, the total vehicle operation cost under certain driving cycles is quantified in the present paper. Then given a certain ambient temperature, a target temperature of preheating is optimized under the principle of minimizing total cost. As for the preheating method, a liquid heating system is also implemented on an electric bus. Simulation results show that the preheating process becomes increasingly necessary with a decreasing ambient temperature; however, the preheating demand declines as driving range grows. Vehicle tests verify that the preheating management strategy proposed in this paper is able to save total vehicle operation cost.
ARTICLE | doi:10.20944/preprints201706.0038.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Public bus transportation; Battery-swapping e-bus; Battery charging; Construction costs; Particle swarm optimization (PSO); PSO-genetic algorithm (GA)
Online: 6 June 2017 (17:52:24 CEST)
The greenhouse gases and air pollution generated by extensive energy use have exacerbated climate change. An electric-bus (e-bus) transportation system favors reducing pollution and carbon emissions. This study analyzed the minimization of construction costs for an all battery-swapping public e-bus transportation system. A simulation was conducted according to existing timetables and routes. Daytime charging was incorporated during the hours of operation; the two parameters of the daytime charging scheme were the residual battery capacity and battery-charging energy during various intervals of daytime peak electricity hours. The parameters were optimized using three algorithms: particle swarm optimization (PSO), a genetic algorithm (GA), and a PSO–GA. This study observed the effects of optimization on cost changes (e.g., number of e-buses, on-board battery capacity, number of extra batteries, charging facilities, and energy consumption) and compared the plug-in and battery-swapping e-bus systems. The results revealed that daytime charging can reduce the construction costs of both systems. In contrast to the other two algorithms, the PSO–GA yielded the most favorable optimization results for the charging scheme. Finally, according to the cases investigated and the parameters of this study, the construction cost of the plug-in e-bus system was lower than that of the battery-swapping e-bus system.
ARTICLE | doi:10.20944/preprints202107.0012.v1
Subject: Engineering, Automotive Engineering Keywords: Air Handling Unit; Battery Room; HVACS; Network Control Panel; and Intrinsic Safe Barrier Module
Online: 1 July 2021 (11:11:23 CEST)
Lead-acid batteries utilised in electrical substations release hydrogen and oxygen when these are charged. These gases could be dangerous and cause a risk of fire if they are not properly ventilated. Therefore, this research seeks to design and implement a network control panel for heating, ventilation, and air-conditioning systems (HVACS). This is done using a specific range of controllers, which have more than thirty loops of proportional, integral and derivative (PID) control to achieve a cost-effective design. It performs the required function of extracting hydrogen, oxygen, and maintaining the desired temperature of the battery storage room within the recommended limits (i.e. 25°C ±1°C tolerance) without compromising quality as set out in the user requirement specification in Appendix-A. The system control panel allows the user to access control parameters such as changing temperature set-points, fan-speed, sensor database amongst others. The hardware is configured to detect extreme hydrogen and oxygen gas content in the battery room and ensure that the HVACS extract the gas content to the outside environment. The results of the system show that the network control panel effectively operates as per the recommended system requirements. Therefore, the effective operation of the HVACS ensures sufficient gas ventilation, thus mitigating the risk of fire in a typical battery storage room. Furthermore, the effective operation of HVACS enhances battery lifespan because of regulated operating temperature, which is conducive to minimise the effect of sulfation in lead acid Batteries (LABs).
ARTICLE | doi:10.20944/preprints202001.0334.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Russia; solar power; hydrogen energy; electric vehicle; lithium battery
Online: 28 January 2020 (05:47:34 CET)
With a relatively small population, Russia accesses huge oil, natural gas, coal and uranium resources, and hosts advanced nuclear energy, oil and natural gas industries. However, the combined effect of today’s low cost electricity generation via photovoltaic modules, water and wind turbines and similarly low cost storage in Li-ion battery and solar hydrogen obtained via water electrolysis will have a profound impact on Russia’s energy and automotive industries.
REVIEW | doi:10.20944/preprints201803.0205.v1
Subject: Engineering, Energy & Fuel Technology Keywords: energy storage; battery; control; energy management systems; FLC; MPC
Online: 26 March 2018 (05:50:33 CEST)
Energy storage has become a fundamental component in renewable energy systems, especially those including batteries. However, during the charging and the discharging process, there are some parameters that are not controlled by the user. That uncontrolled working leads to aging of the batteries and a reduction of their life cycle. Therefore, it causes an early replacement. Different control methods have been developed with the goal of protecting the battery and extending its life expectancy, being the most used the constant current-constant voltage. However, several studies show that charging time can be reduced by using Fuzzy Logic Control or Model Predictive Control. Other benefits are; temperature control and an extension of life expectancy. For all these reasons, FLC and MPC have proven to be more efficient than traditional charge control methods.
ARTICLE | doi:10.20944/preprints201811.0616.v1
Subject: Engineering, Energy & Fuel Technology Keywords: photovoltaic; optimization; payback time; battery; sensitivity analysis
Online: 29 November 2018 (04:09:57 CET)
The current work investigates how adding a battery of optimal capacity to a grid-connected photovoltaic (PV) system can improve its economic feasibility. Also, the effect of different parameters on the feasibility of the PV system was evaluated. The OBC was determined for different saving targets of the annual electricity consumption of the chosen building. For this aim, real electricity consumption data of a residential building in Landskrona, Sweden, was used as energy consumption profile. Solar World SW325XL, which is a monocrystalline solar panel, was selected as PV panels. The calculations were performed under the metrological and economic conditions of southern Sweden. Different working parameters (WP)were considered (prices of the battery, feed-in tariffs, and saving targets). The performed calculations show that the optimal battery capacity (OBC), in which the payback time (PBT) of the system is maximized, strongly depends on the WP. The proper selection of the battery can considerably increase the economic feasibility of the PV system in southern Sweden. However, in some cases, using battery can have a negative impact on the PBT of the system. The results show that the electricity price, the module price, the inverter price, and the inverter lifetime have the highest effect on the PBT.
COMMUNICATION | doi:10.20944/preprints202201.0051.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Electric vehicles; Battery thermal management system; Li-Ion batteries
Online: 6 January 2022 (09:39:49 CET)
Electric Vehicles (EVs) are the need of the hour due to growing climate change problems linked with the transportation sector. Battery Thermal Management System (BTMS), which is accountable for certifying safety and performance of lithium-ion batteries (LiB), is the most vital part of an EV. LiB has auspicious gravimetric energy density but the heat generation due to chemical reactions inside a LiB during charging and discharging causes temperature rise which has a direct effect on LiB performance and safety. This study specifically focuses on aircooled BTMS, defines different types of air-cooled BTMS (active and Passive), discusses limitations associated with air-cooled BTMS, and investigates different optimization techniques and parameters to improve performance of air-cooled BTMS. Maintaining temperature within optimum range and uniform temperature distribution between cells of a battery pack are the major design parameters for improving the performance and efficiency of air-cooled BTMS. Various optimization techniques including cell arrangement with a battery pack, air-flow channel optimization, and air inlet/outlet position variations are discussed and each technique is thoroughly reviewed. Finally, it’s noted that passive air-cooled BTMS is not that effective for long-distance vehicles so most researchers shifted their focus toward active air-cooled BTMS. Active air-cooled BTMS requires a lot of power for effective performance. Lastly, the most recent field of air-cooled BTMS technology which is Air-Hybrid BTMS is discussed and declared a very promising solution for overcoming major limitations associated with air-cooled BTMS.
ARTICLE | doi:10.20944/preprints201810.0135.v2
Subject: Engineering, Electrical & Electronic Engineering Keywords: lead acid battery; supercapacitor; DC/DC converter; state-of-charge
Online: 25 October 2018 (09:40:30 CEST)
Lead Acid Batteries (LABs) are used for starting, lighting, and igniting, as well as in air conditioning systems and to supply power to electric engines in transport vehicles (TVs). However, the application of LABs for TVs has faced a number of market challenges, mounted by the upcoming high energy density and long lifespan batteries, such as lithium ion. LABs, on the other hand, are inexpensive. The key research question is, how can the lifespan of LABs used in automotive industries be increased, while still ensuring a low cost solution? Thus, integrating LABs with the supercapacitor (known as an electric double layer capacitor—EDLC) is likely to outperform the competing alternative batteries for TVs. This paper proposes a multiple stage approach to hybrid lead acid batteries and a supercapacitor system for TVs that is capable of maintaining the battery state-of-charge (SOC) at statistically high limits, ranging between 90% and 95%. This SOC target will likely ensure that the lifespan of the hybrid battery system can be elongated (extended) more than its competitors. In this study, the multiple stage approach of concatenated converters has been designed in order to satisfy all energy storage requirements for different characteristics of LABs and the supercapacitor. The designed hybrid system has been simulated using Matrix Laboratory (MATLAB/Simulink (version R2016a, MathWorks, Natick, MA, USA)). The simulated results show that high transient currents from the direct current (DC) bus of LABs, caused by the regenerative braking or deceleration of the TVs, reduce the battery lifespan and induce mechanical stress. The supercapacitor reduces the stress on the LAB by absorbing high transient currents. This, in turn, keeps the LABs’ SOC between 90% and 96% and the voltage at 12 V. As indicated by the simulated results, the hybrid battery SOC is maintained at 90–96% and the terminal voltage is approximately 12 V.
ARTICLE | doi:10.20944/preprints201905.0012.v1
Subject: Chemistry, Other Keywords: lithium-ion battery; battery recycling; battery electric vehicle; circular economy
Online: 5 May 2019 (11:10:23 CEST)
Driven by the rapid uptake of battery electric vehicles, Li-ion power batteries are increasingly reused in stationary energy storage systems, and eventually recycled to recover all the valued components. Offering an updated global perspective, this study provides a circular economy insight on lithium-ion battery reuse and recycling.
ARTICLE | doi:10.20944/preprints201808.0037.v3
Subject: Engineering, Energy & Fuel Technology Keywords: converter-based microgrids; renewable energy sources; optimum battery control; real-time energy management; particle swarm optimisation
Online: 14 January 2019 (10:15:30 CET)
Real-time energy management of a converter-based microgrid is difficult to determine optimal operating points of a storage system in order to save costs and minimise energy waste. This complexity arises due to time-varying electricity prices, stochastic energy sources and power demand. Many countries have imposed real-time electricity pricing to efficiently control demand side management. This paper presents a particle swarm optimisation (PSO) for the application of real-time energy management to find optimal battery controls of a community microgrid. The modification of the PSO consists in altering the cost function to better model the battery charging/discharging operations. As optimal control is performed by formulating a cost function, it is suitably analysed and then a dynamic penalty function in order to obtain the best cost function is proposed. Several case studies with different scenarios are conducted to determine the effectiveness of the proposed cost function. The proposed cost function can reduce operational cost by 12% as compared to the original cost function over a time horizon of 96 hours. Simulation results reveal the suitability of applying the regularised PSO algorithm with the proposed cost function, which can be adjusted according to the need of the community, for real-time energy management.
ARTICLE | doi:10.20944/preprints202006.0205.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Energy management schemes; particle swarm optimisation; community microgrids; scheduling battery energy; real-time energy management and renewable energy
Online: 16 June 2020 (09:46:03 CEST)
Although energy management of a microgrid is generally performed using a day-ahead scheduling method, its effectiveness has been questioned by the research community due to the existence of high uncertainty in renewable power generation, power demand and electricity market. As a result, real-time energy management schemes are recently developed to minimise the operating cost of a microgrid while high uncertainty presents in the network. This paper develops modified particle swarm optimisation (MPSO) algorithms to solve optimisation problems of energy management schemes for a community microgrid and proposes a scheduling approach after taking into consideration high uncertainty to effectively minimise the operational cost of the microgrid. The optimisation problems are formulated for real-time and scheduling approaches, and solution methods are developed to solve the problems. It is observed that the scheduling program demonstrates superior performance in all the cases, including uncertainty in prediction, as compared to the other energy management approaches, although solutions have significant deviations due to prediction errors.
Subject: Engineering, Automotive Engineering Keywords: Energy Efficiency; Emissions; Tribology; Lubrication; Battery Electric Vehicles; Hybrid Electric Vehicles; Life Cycle Analysis; Thermal Cooling Fluids
Online: 17 June 2021 (10:46:41 CEST)
The motivations for the move to electrified vehicles are discussed with reference to their improved energy efficiency, their potential for lower CO2 emissions (if the electricity system is decarbonized), their lower (or zero) NOx/particulate matter (PM) tailpipe emissions, and the lower overall costs for owners. Some of the assumptions made in life-cycle CO2 emissions calculations are discussed and the effect of these assumptions on the CO2 benefits of electric vehicles are made clear. A number of new tribological challenges have emerged, particularly for hybrid vehicles that have both a conventional internal combustion engine and a battery, such as the need to protect against the much greater number of stop-starts that the engine will have during its lifetime. In addition, new lubricants are required for electric vehicle transmissions systems. Although full battery electric vehicles (BEVs) will not require engine oils (as there is no engine) they will require a system to cool the batteries – alternative cooling systems are discussed, and where these are fluid based, the specific fluid requirements are outlined.
ARTICLE | doi:10.20944/preprints201804.0303.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: multi-objective optimization; optimal configuration; improved gravitational search algorithm (IGSA); wind-solar-battery system; demand response
Online: 24 April 2018 (04:05:05 CEST)
This study presents application of demand response strategy in a standalone wind-solar-battery hybrid energy system (HES). Inputs for the designed HES are wind speed, solar radiation, temperature and load demand which is variable with time. In this study, hourly values of meteorological data and hourly load demand are considered in one year. An improved gravitational search algorithm (IGSA) is used to optimize the configuration of the standalone wind-solar-battery hybrid power system. The optimal objectives of the system are cost of the system in life cycle, the loss of power supply probability（LPSP）and the energy excess percentage（EXC）.The effect of demand response on economic benefit and energy storage allocation of the standalone wind-solar-battery system is studied. The obtained optimal configuration of the proposed HES can provide minimal energy cost with excellent performance and reduced waste and unmet load.
ARTICLE | doi:10.20944/preprints202205.0379.v1
Subject: Engineering, Control & Systems Engineering Keywords: Battery autonomy; battery size; feature selection; Machine Learning; Optimization algorithms
Online: 27 May 2022 (10:12:42 CEST)
Microgrids are becoming popular nowadays because they provide clean, efficient, and low-cost energy. To use the stored energy in times of emergency or peak loads, microgrids require bulk storage capacity. Since microgrids are the future of renewable energy, the energy storage technology employed should be optimized to generate electricity. Batteries play a variety of essential roles in daily life and are used at peak hours and during a time of emergency. There are different types of batteries i.e., lion batteries, lead-acid batteries, etc. Optimal battery sizing of microgrids is a challenging problem, that limits modern technologies such as electric vehicles, etc. It is important to know different battery features such as battery life, battery throughput, and battery autonomy to get optimal battery sizing for microgrids. Mixed-integer linear programming (MILP) is an established technique for the integration and optimization of different energy sources and parameters for optimal battery sizing. A new MILP based dataset is introduced in this work. Support vector machine (SVM) is the machine learning application used to estimate the optimum battery size. The impact of feature selection algorithms on the proposed machine learning-based model is evaluated. The performance of the six best-performing feature selection algorithms is analyzed. The experimental results show that the feature selection algorithms improve the performance of the proposed methodology. Ranker search shows the best performance with a Spearman’s rank-ordered correlation constant of 0.9756, linear correlation constant of 0.9452, Kendall correlation constant of 0.8488 and root mean squared error of 0.0525.
REVIEW | doi:10.20944/preprints202108.0334.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Electric Vehicle; Internet of Things (IoT); Bluetooth; Cloud-Battery Management System; ZigBee; Controller Area Network (CAN); Wi-Fi; Charger
Online: 16 August 2021 (12:20:13 CEST)
An effective battery management system (BMS) is indispensable for any lithium-ion battery (LIB) powered systems such as electric vehicles (EVs) and stationary grid-tied energy storage systems. Massive wire harness, scalability issue, physical failure of wiring, and high implementation cost and weight are some of the major issues in conventional wired-BMS. One of the promising solutions researchers have come up with is the wireless BMS (WBMS) architecture. Despite research and development on WBMS got momentum more than a decade ago, it is still in a preliminary stage. Significant further upgradation is still required towards developing an industry-ready WBMS, especially for high-power LIB packs. Therefore, an in-depth survey exclusively on WBMS architectures is presented in this article. The aim is to provide a summary of the existing developments as well as to present an informative guide to the research community for future development by highlighting the issues, emerging trends, and challenges. In-depth analysis of the existing WBMS topologies will not only help the researchers to understand the existing challenges and future research scopes clearly while at the same time enthuse them to focus their research inclination in the domain of WBMS.
ARTICLE | doi:10.20944/preprints202110.0053.v1
Subject: Materials Science, General Materials Science Keywords: lithium-ion battery; anode battery; lithium-ion thermodynamics; solid-state synthesis
Online: 4 October 2021 (11:54:45 CEST)
Li3FeN2 material was synthesized by two-step solid-state method from Li3N (adiabatic camera) and FeN2 (tube furnace) powders. Phase investigation of Li3N, FeN2 and Li3FeN2 were carried out. Discharge capacity of Li3FeN2 is 343 mAh g-1, that is about 44.7% of theoretic capacity. The molar heat capacity of Li3FeN2 at constant pressure in the temperature range 298-900 K should be calculated as Cp,m = 77,831 + 0,130 × T – 6,289 × T-2, where T is absolute temperature, . Thermodynamic characteristics of Li3FeN2 were determined as next: entropy S0298 = 116.2 J mol-1 K-1, molar enthalpy of dissolution ΔdHLFN = ˗ 206,537 ± 2,8 kJ mol−1, the standard enthalpy of formation ΔfH0 = ˗ 291.331 ± 5.7 kJ mol−1, entropy S0298 = 113.2 J mol-1 K-1 (Neumann-Kopp rule) and 116.2 J mol-1 K-1 (W.Herz rule), the standard Gibbs free energy of formation ∆f G0298 = ˗276,7 kJ mol-1.
ARTICLE | doi:10.20944/preprints201803.0122.v1
Subject: Engineering, Energy & Fuel Technology Keywords: electric vehicle; Nissan Leaf; lithium-ion battery; capacity loss; battery degradation
Online: 15 March 2018 (07:19:52 CET)
Analysis of 1382 measures of battery State of Health (SoH) from 283 Nissan Leafs (“Leaf/s”), manufactured between 2011 and 2017, has detected a faster rate of decline in this measure of energy-holding capacity for 30 kWh variants. At two years of age, the mean rate of decline of SoH of 30 kWh Leafs was 9.9% per annum (95% uncertainty interval of 8.7% to 11.1%; n = 82). This was around three times the rate of decline of 24 kWh Leafs which at two years averaged 3.1% per annum (95% uncertainty interval of 2.9% to 3.3%; n = 201). For both variants there was evidence for an increasing rate of decline as they aged, although this was much more pronounced in the 30 kWh Leafs. Higher use of rapid DC charging was associated with a small decrease in SoH. Additionally, while 24 kWh cars with greater distances travelled showed a higher SoH, in 30 kWh cars there was a reduction in SoH observed in cars that had travelled further. The 30 kWh Leafs sourced from United Kingdom showed slower initial decline than those from Japan, but the rate of decline was similar at two years of age. Improvements in the battery health diagnostics, continuous monitoring of battery temperatures and state of charge, and verification of a fundamental model of battery health are needed before causes and remedies for the observed decline can be pinpointed. If the high rate of decline in battery capacity that we observed in the first 2.3 years of a 30 kWh Leaf’s lifetime were to continue, the financial and environmental benefits of this model may be significantly eroded. Despite 30 kWh Leafs accounting for only 14% of all light battery electric vehicles registered for use on New Zealand roads at the end of February 2018, there is also the potential for the relatively poor performance of this specific model to undermine electric vehicle uptake more generally unless remedies can be found.
ARTICLE | doi:10.20944/preprints202112.0522.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: lithium battery; electrochemical power sources; diagnostics; battery management system; load variation; in situ method
Online: 31 December 2021 (12:59:15 CET)
The relaxation process of lithium batteries caused by load variation is considered. It is shown that such processes have strong dependence on internal physical and chemical processes and battery technical conditions. Theoretical expressions of the relaxation process caused by a step-like load variation have been obtained for 1st and 2nd order equivalent electrical circuits. The experimental investigations show that the obtained models fit the real relaxation processes and the behavior of the identified parameters could be explained by specific features of physical and chemical processes within the lithium battery. It should be noted that the obtained results can be generalized for a different type of electrochemical power source. The proposed approach makes it possible to provide means for electrochemical power source characterization and diagnostic, the main advantages of which are good time localization of measurement procedures and inexpensive apparatus implementation.
ARTICLE | doi:10.20944/preprints202110.0004.v2
Subject: Engineering, Energy & Fuel Technology Keywords: cycle aging; Lithium battery; stochastic algorithm
Online: 29 October 2021 (12:08:24 CEST)
The prediction of capacity degradation, and more generally of the behaviors related to battery aging, is useful in the design and use phases of a battery to help improve the efficiency and reliability of energy systems. In this paper, a stochastic model for the prediction of battery cell degradation is presented. The proposed model takes its cue from an approach based on Markov chains, although it is not comparable to a Markov process, as the transition probabilities vary as the number of cycles that the cell has performed varies. The proposed model can reproduce the abrupt decrease in the capacity that occurs near the end of life condition (80% of the nominal value of the capacity) for the cells analyzed. Furthermore, we illustrate the ability of this model to predict the capacity trend for a lithium-ion cell with nickel-manganese-cobalt (NMC) at the cathode and graphite at the anode subjected to a life cycle in which there are different aging factors, using the results obtained for cells subjected to single aging factors.
ARTICLE | doi:10.20944/preprints201808.0046.v1
Subject: Materials Science, General Materials Science Keywords: cobalt hydroxide; LiCoO2; lithium-ion battery
Online: 2 August 2018 (10:14:51 CEST)
Crystalline β-cobalt hydroxide (β-Co(OH)2) of different morphologies have been successfully synthesized with the addition of sodium hydroxide to cobalt nitrate solution and aging in the mother liquor. The rate of NaOH addition, ranging from 0.1 mL/min to 10 mL/min, influences the surface morphology with the obtained storage capability of the respective electrode. Characterization of the β-Co(OH)2 was fully developed, including X-ray diffraction, scanning and transmission electron microscopy, and BET analyses. At a lower rate of NaOH addition, particles are like platelets, while for a higher rate (≥2 mL/min) grains are fused together forming a larger crystallite size. This result is supported by the X-ray diffraction structural analysis, where the phase evolution of (002) plane becomes distinct for the higher rate of NaOH addition. Lithium cobalt oxide (LiCoO2) was synthesized through oxidation from the as-prepared β-Co(OH)2 and LiOH. The electrochemical performance of as obtained LiCoO2 is investigated using charge-discharge and cyclic voltammetric studies. The precursor β-Co(OH)2 prepared at a lower rate of 0.1 mL/min in LiCoO2 demonstrated the best electrochemical performance of 155 mAh/g. After 50 cycles, the capacity retention rate was 67% compared with the first cycle. Finally, we have attempted to correlate the amount of the available OH- ions with the formation of platelets and the discharge capacity. This work has developed a methodology for the synthesis of LiCoO2 using β-Co(OH)2 in a facile chemical solution process.
ARTICLE | doi:10.20944/preprints201808.0145.v1
Subject: Materials Science, Biomaterials Keywords: secondary lithium ion battery; all-solid-state battery; solid polymer electrolyte; succinonitrile (SN); lithium(trifluoromethanesulfonyl)imide (LiTFSI)
Online: 7 August 2018 (13:18:20 CEST)
Considering the safety issues of Li ion batteries, all-solid-state polymer electrolyte has been one of the promising solutions. In this point, achieving a Li ion conductivity in the solid state electrolytes comparable to liquid electrolytes (>1 mS/cm) is particularly challenging. Employment of polyethylene oxide (PEO) solid electrolyte has not been not enough in this point due to high crystallinity. In this study, hybrid solid electrolyte (HSE) systems are designed with Li1.3Al0.3Ti0.7(PO4)3(LATP), PEO and Lithium hexafluorophosphate (LiPF6) or Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Hybrid solid cathode (HSC) is also designed using LATP, PEO and lithium cobalt oxide (LiCoO2, LCO)—lithium manganese oxide (LiMn2O4, LMO). The designed HSE system displays 3.0 × 10−4 S/cm (55 ℃) and 1.8 × 10−3 S/cm (23 ℃) with an electrochemical stability as of 6.0 V without any separation layer introduction. Li metal (anode)/HSE/HSC cell in this study displays initial charge capacity as of 123.4/102.7 mAh/g (55 ℃) and 73/57 mAh/g (25 °C). To these systems, Succinonitrile (SN) has been incorporated as a plasticizer for practical secondary Li ion battery system development to enhance ionic conductivity. The incorporated SN effectively increases the ionic conductivity without any leakage and short-circuits even under broken cell condition. The developed system also overcomes the typical disadvantages of internal resistance induced by Ti ion reduction. In this study, optimized ionic conductivity and low internal resistance inside the Li ion battery cell have been obtained, which suggests a new possibility in the secondary Li ion battery development.
ARTICLE | doi:10.20944/preprints202101.0223.v1
Subject: Engineering, Automotive Engineering Keywords: UDS-Diagnosis; Battery Twin; Data Logger; SOH
Online: 12 January 2021 (14:26:14 CET)
Li-ion battery packs are the heart of modern electric vehicles. Due to their perishable nature, it is crucial to supervise them closely. In addition to on-board supervision over safety and range, insights into the battery’s degradation are also becoming increasingly important, not only for the vehicle manufacturers but also for vehicle users. The concept of digital twins has already emerged on the field of automotive technology, and can also help to digitalize the vehicle’s battery. In this work, we set up a data pipeline and digital battery twin to track the battery state, including state of charge (SOC), state of health (Capacity) (SOHc ) and state of health (Resistance) (SOHr ). To achieve this goal, we reverse-engineer the diagnostics interface of a 2014 e-Golf to query for Unified Diagnostic Services (UDS) messages containing both battery pack and cell-individual data. An on-board diagnosis (OBD) logger records the data with edge-processing capability. Pushing this data into the cloud twin system using IoT-technology, we can fit battery models to the data and infer cell individual internal resistance from them. We find that the resistances of the cells differ by a magnitude of two. Furthermore, we propose an architecture for the battery twin in which the twin fleet shares resources like models by encapsulating them in Docker containers run on a cloud stack. By using web technology, we present the analyzed results on a web interface.
ARTICLE | doi:10.20944/preprints202007.0074.v1
Subject: Physical Sciences, Condensed Matter Physics Keywords: Correlated Materials; Battery Materials; DMFT; DFT; MoO2
Online: 5 July 2020 (12:50:22 CEST)
Motivated by experiments, we undertake an investigation of electronic structure reconstruction and its link to electrodynamic responses of monoclinic MoO$_2$. Using a combination of LDA band structure with DMFT for the subspace defined by the physically most relevant Mo $4d$-bands, we unearth the importance of multi-orbital electron interactions to MoO$_2$ parent compound. Supported by a microscopic description of quantum capacity we identify the implications of many-particle orbital reconstruction to understanding and evaluating voltage-capacity profiles intrinsic to MoO$_2$ battery material. Therein, we underline the importance of the dielectric function and optical conductivity in the characterisation of existing and candidate battery materials.
ARTICLE | doi:10.20944/preprints201811.0240.v1
Subject: Engineering, Energy & Fuel Technology Keywords: thermal battery; polyimide; cathode; slurry casting; binder
Online: 9 November 2018 (04:23:11 CET)
The polymer binder, poly(imide-co-siloxane) (PIS), was synthesized and applied to form a thin cathode layer composites for a thermal battery that has an unusually high operating temperature of 450 °C. The PIS was prepared through cross-linking of the polyimide with polysiloxane. The morphology of FeS2/PIS composites showed that FeS2 particles was coated with the PIS cross-linked gel. The FeS2/PIS composites enabled to fabricate mechanically stable thin cathode layer that was 20–10% of the thickness of a conventional pellet-type cathode. The FeS2/PIS composites were stable up to 400 °C and maintained their morphology at this temperature. PIS coating layers decomposed at 450 °C and a new residue was generated, which was observed by transmission electron microscopy and the compositional change was analyzed. The FeS2/PIS composites showed enhanced thermal stability over that of FeS2 in thermogravimetric analysis. The thermal battery with the PIS polymer binder showed a 20% discharge capacity increase when compared to a conventional pellet-type cathode.
REVIEW | doi:10.20944/preprints201807.0011.v1
Subject: Materials Science, Polymers & Plastics Keywords: PVDF; copolymers; battery separator; lithium-ion batteries
Online: 2 July 2018 (12:20:58 CEST)
The separator membrane is an essential component of lithium-ion batteries, separating the anode and cathode and controlling the number and mobility of the lithium ions. Among the polymer matrices most investigated for battery separators are poly(vinylidene fluoride) (PVDF) and its copolymers poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), and poly(vinylidene fluoride-cochlorotrifluoroethylene) (PVDF-CTFE), due to their excellent properties such as high polarity and the possibility of controlling the porosity of the materials through binary and ternary polymer/solvent systems, among others. This review presents the recent advances on battery separators based on poly(vinylidene fluoride) (PVDF) and its copolymers for lithium-ion batteries. It is divided in the following sections: single polymer and co-polymers, surface modification, composites and polymer blends. Further, a critical comparison between those membranes and other separator membranes is presented, as well as the future trends on this area.
ARTICLE | doi:10.20944/preprints201806.0277.v1
Subject: Engineering, Energy & Fuel Technology Keywords: battery charger; photovoltaic module array; LiFePO4 battery; Buck converter; maximum power point tracker; smart two-stage charging strategy
Online: 18 June 2018 (15:55:50 CEST)
This paper aims to present a smart high speed battery charger, powered by a photovoltaic module array, for a LiFePO4 battery as a solar energy storage device. With a battery charging strategy, the presented battery charger involves a Buck converter as the core equipped with a simple maximum power point (MPP) tracker. Considering complexity reduction and easy hardware implementation, a constant voltage MPP tracking approach is adopted such that the maximum amount of output power can be delivered to the load in response to an arbitrary change in the solar radiation. A smart two-stage charging strategy, with a constant current mode followed by a constant voltage mode, is employed in such a way that the battery charge process can be accelerated largely, while the damage caused by overcharging can be prevented. In the end, the performance of this proposal is validated experimentally.
ARTICLE | doi:10.20944/preprints202207.0129.v1
Subject: Materials Science, General Materials Science Keywords: recycled electrode; spent battery; spectroscopic method; cyclic voltammetry
Online: 8 July 2022 (03:31:38 CEST)
The novelty of this study consists in: i) synthesis and characterization of electrode materials recycled from a spent car battery and doped with MnO2 and CuO by the analysis of X-ray diffraction (XRD), Infrared (IR) and Electron Paramagnetic Resonance (EPR) data and ii) the investigation of electrochemical properties of prepared materials in view of new applications as electrode materials for battery. Electron Paramagnetic Resonance (EPR) data indicate that the intensity of the resonance line corresponding to the Cu+2 ion was modified with the increase of the dopant content. The analysis of X-ray Absorption Spectroscopy (XAS) data indicates that by increasing the dopant content there is a process of ordering the oxygen atoms around the lead similar to the PbO2 theoretical model. The electrochemical performances of the recycled and manganese-copper-doped materials are optimized for applications as new anodic electrode for the car battery.
ARTICLE | doi:10.20944/preprints202107.0465.v1
Subject: Engineering, Automotive Engineering Keywords: Optimal control; frequency regulation; battery energy storage system
Online: 20 July 2021 (16:28:04 CEST)
The increasing penetration of renewable energy sources in power grids highlights the role of battery energy stor- age systems (BESSs) in enhancing the stability and reliability of electricity. A key challenge with the renewables’, specially the BESSs, integration into the power system is the lack of proper dynamic model for stability analysis. Moreover, a proper control design for the power system is a complicated issue due to its complexity and inter-connectivity. Thus, the application of decentralized control to improve the stability of a large- scale power system is inevitable, especially in distributed energy sources (DERs). This paper presents an optimal distributed hybrid control design for the interconnected systems to suppress the effects of small disturbances in the power system employing utility-scale batteries based on existing battery models. The results show that i) the smart scheduling of the batteries’ output reduces the inter-area oscillations and improves the stability of the power systems; ii) the hybrid model of the battery is more user-friendly compared to the Western electricity coordinating council (WECC) model in power system analysis.
ARTICLE | doi:10.20944/preprints202008.0564.v1
Subject: Chemistry, Electrochemistry Keywords: Li-ion battery; computer simulation; numerical method; software
Online: 26 August 2020 (07:45:40 CEST)
This code provides computational facilities to simulate current versus time during the charging of Li-ion cells at desire constant voltage by considering multiscale physical phenomena. This code only considers a powder of active materials (at microscale or nanoscale) and a small part of electrolyte around it as a half cell. Then it is extended to a complete cell by applying correct boundary conditions. This code is very useful by modifying code parameters to understand the effect of the complex shape of active materials powder (surface area and powder size), kind of electrolyte, and the applied voltages on the charging response of Li-ion cell. As a summary, a microscale approach to the design of Li-ion cells has been provided via this code.
ARTICLE | doi:10.20944/preprints202007.0684.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: activity-based costing; battery pack; e-motorcycle conversion
Online: 28 July 2020 (13:55:20 CEST)
Universitas Sebelas Maret (UNS) through SMART UNS Company has conducted research and development of e-motorcycle conversion using Li-ion battery pack as a substitute for ICE energy source from the conventional motorcycle. Currently, the battery-pack that used for e-motorcycle conversion is in the development phase towards commercialization. The challenge of estimating production costs is the complicated production process and storing hidden expenses that can be a problem. This hidden cost is often a missing or varied factor that costs less or more expensive. This study presents an integrated parametric cost estimation model with activity-based cost assignments to estimate production costs through cost calculations for each activity. Activity-based costs break the production process into a specific cost element for each step. Each activity's cost is put into a parametric cost estimation model to calculate the cost of each activity into the total cost of production. Cost estimation results will be analyzed using a regression method to determine which variables most affect the production cost of Li-ion battery packs for the conversion of e-motorcycles in the SMART UNS company.
ARTICLE | doi:10.20944/preprints201805.0091.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: battery; commercialization; markov chain; new technology; techno-economic
Online: 4 May 2018 (10:16:46 CEST)
LiFePO4 (LFP) or Lithium-ion battery with its advantages compared to common current motorcycle battery is an appropriate alternative in substituting wet and dry cell battery. Huge amount of demand of motorcycle along with the battery in Indonesia also make it an interesting product for business. In order to assess the commercial potential for such a new technology, market share needs to be estimated as well as the techno-economic feasibility. Hence, market share prediction using the residents of Surakarta Region and techno-economic analysis using NPV, IRR and PBP indicators have been conducted in this study. Calculation using markov chain method shows that LFP battery tends to dominate the market after certain period. Techno-economic analysis also figures out that the commercialization is feasible in three conditions - first mover, even with market leader and equilibrium point. Therefore, there is a great commercial potential for LFP battery especially in Indonesia.
ARTICLE | doi:10.20944/preprints201608.0019.v1
Subject: Engineering, Energy & Fuel Technology Keywords: redox flow battery; techno-economic analysis; materials; cost
Online: 2 August 2016 (11:41:32 CEST)
A techno-economic model was developed to investigate the influence of components on the system costs of redox flow batteries. Sensitivity analyses were carried out based on a example of a 10 kW/120 kWh vanadium redox flow battery system and the costs of the individual components were analyzed. Particular consideration was given to the influence of material costs and resistances of bipolar plates and energy storage media as well as voltages and electric currents. Based on the developed model it was possible to formulate statements about the targeted optimization of existing battery systems and general aspects for future developments of redox flow batteries.
ARTICLE | doi:10.20944/preprints201811.0459.v1
Subject: Materials Science, General Materials Science Keywords: Lithium-Ion Battery; Cathode Material; Spinel LiMn2O4; Sodium Substitution
Online: 19 November 2018 (11:30:42 CET)
Sodium substitution Li1-xNaxMn2O4 cathodes were synthesized by a solid-state reaction method. The morphologies and crystal structures of Li1-xNaxMn2O4 were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. All Li1-xNaxMn2O4 samples exhibited a single phase LiMn2O4 spinel structure with good crystallinity. The effect of Na+ ions on the electrochemical performance of Li1-xNaxMn2O4 was investigated by galvanostatic charge-discharge test. The results showed that lithium substituted by sodium deteriorated its capacity retention but enhance its discharge capacity when it worked at large current densities. The initial discharge capacity was 114.2 mAh/g for Li0.94Na0.06Mn2O4, and 93.1 mAh/g remained after 300 cycles at a current density of 2220 mA/g in the voltage range 3.0–4.3 V at room temperature.
ARTICLE | doi:10.20944/preprints202107.0087.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Electric Vehicles; Stationary Battery Energy Storage System; Battery Automated System; Online State Estimation; Thermal Modeling; First-order model; Second-order Model; Kalman Filtering
Online: 5 July 2021 (10:11:31 CEST)
Estimation of core and surface temperature is one of the crucial functionalities of the lithium-ion Battery Management System (BMS) towards providing effective thermal management, fault detection and operational safety. While, it is impractical to measure core temperature using physical sensors, implementing a complex estimation strategy in on-board low-cost BMS is challenging due to high computational cost and the cost of implementation. Typically, a temperature estimation scheme consists of a heat generation model and a heat transfer model. Several researchers have already proposed ranges of thermal models having different levels of accuracy and complexity. Broadly, there are first-order and second-order heat capacitor-resistor-based thermal models of lithium-ion batteries (LIBs) for core and surface temperature estimation. This paper deals with a detailed comparative study between these two models using extensive laboratory test data and simulation study to access suitability in online prediction and onboard BMS. The aim is to guide whether it’s worth investing towards developing a second-order model instead of a first-order model with respect to prediction accuracy considering modelling complexity, experiments required and the computational cost. Both the thermal models along with the parameter estimation scheme are modelled and simulated using MATLAB/Simulink environment. Models are validated using laboratory test data of a cylindrical 18650 LIB cell. Further, a Kalman Filter with appropriate process and measurement noise levels are used to estimate the core temperature in terms of measured surface and ambient temperatures. Results from the first-order model and second-order models are analyzed for comparison purposes.
ARTICLE | doi:10.20944/preprints202209.0414.v1
Subject: Materials Science, Polymers & Plastics Keywords: lithium sulfur battery; polysulfide; shuttle effect; dendrite; polyaniline; graphite; COMSOL
Online: 27 September 2022 (07:38:09 CEST)
To mitigate lithium dissolution and polysulfide shuttle effect phenomena in high energy lithium sulfur batteries (LISBs), a conductive, flexible, and easily modified polymer composite layer was applied on the anode. The polymer composite layer includes polyaniline and functionalized graphite. The electrochemical behavior of LISBs was studied by galvanostatic charge/discharge tests from 1.7 to 2.8 V up to 90 cycles and via COMSOL Multiphysics simulation software. No apparent overcharge occurred during the charge state, which suggests that the shuttle effect of polysulfides was effectively prevented. The COMSOL Multiphysics simulation provides a venue for optimal prediction of the ideal concentration and properties of the polymer composite layer to be used in the LISBs. The testing and simulation results determined that the polymer composite layer diminished the amount of lithium polysulfide species and decreased the amount of dissolved lithium ions in the LISBs. In addition, the charge/discharge rate of up to 2.0 C with a cycle life of 90 cycles was achieved. The knowledge acquired in this study was important not only for the design of efficient new electrode materials, but also for understanding the effect of the polymer composite layer on the electrochemical cycle stability.
REVIEW | doi:10.20944/preprints202208.0448.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Electric Vehicles; Review; SOC Estimation; Deep Learning; Lithium-ion Battery
Online: 26 August 2022 (04:43:03 CEST)
As one of the critical state parameters of the battery management system, lithium battery state of charge (SOC) can provide an essential reference for battery safety management, charge/discharge control, and energy management of electric vehicles. To analyze the application of deep learning in electric vehicle power battery SOC estimation, this study reviewed the technical process, common public datasets, and the neural networks used, structural characteristics, advantages and disadvantages of lithium battery SOC estimation in deep learning method. First, the specific technical processes of the deep learning method for SOC estimation were analyzed, including data collection, data preprocessing, feature engineering, model training, and model evaluation. Secondly, the current commonly and publicly used lithium battery dataset was summarized. Then, the input variables, data sets, errors, and advantages and disadvantages of four types of deep learning methods, were concluded using the structure of neural network used for training as the classification criterion. Finally, the challenges and future development directions of lithium battery SOC estimation in deep learning method were explained.
ARTICLE | doi:10.20944/preprints202104.0758.v1
Subject: Social Sciences, Accounting Keywords: abused women; neuropsychological sequelae; attention; memory; depression; Luria DNA battery
Online: 28 April 2021 (15:47:08 CEST)
Abstract Women victims of abuse can suffer neuropsychological sequelae that affect memory and attention, as well psychopathological disorders such as depression. These consequences affect their daily life and physical and psychological health. Objective: To analyze sequelae that affect attention and memory, as well a possible association of these sequelae to depression. Method: A total of 68 women victims of gender-based violence participated in the study. The participants were between 15 and 62 years of age and resided in Spain at the time of data collection. The Luria DNA Battery (Neuropsychological Diagnosis of Adults) by Manga and Ramos (2000); and the Beck Depression Inventory were applied. Results: Women victims of gender-based violence suffer neuropsychological sequelae, presenting low short-term memory and attentional control; and score low on the Luria-DNA battery. Of these women, 60% suffer from some relevant type of depression, and there are significant differences according to their degree of memory. Through the HJ-Biplot, a direct relationship was found between memory and attentional control with the total score of the Luria battery. On the other hand, an inverse relationship was found between short-term memory and depression. Lastly, three well-differentiated gender clusters of women victims of gender-based violence were identified. Conclusions: A lower rate of depression is observed in women victims of abuse when they have a more intact short-term memory.
ARTICLE | doi:10.20944/preprints202007.0669.v1
Subject: Keywords: volt-ampere characteristics; battery mathematical model; mechanism function; fuel cell
Online: 28 July 2020 (09:39:10 CEST)
The corrected mechanism model of battery voltammetric function is helpful to guide the development and application of battery. There are two scientific issues that need to be answered: First, how many mechanisms do batteries have; Second, how to establish the mechanism model separately under the overlapping of these mechanisms. Volt-ampere characteristics of both linear state and nonlinear state exist; the monotonic decreasing of volt-ampere characteristics indicates that the battery have only three kinds of mechanisms. Without changing the basic form of the function and under the principle of the mechanism function’s working region considered, we propose a mechanism function which satisfies the monotonic decreasing characteristic of the voltammetric curve of battery, via the derivative law of each mechanism function in the voltammetric function of battery. By using the voltammetric data, the obtained cell mechanism function can accurately predict the potential (current or voltage) when the independent variable of the cell is zero, and provide the theoretical basis for the internal working mechanism of the cell, which can guide the practice.
ARTICLE | doi:10.20944/preprints201810.0395.v1
Subject: Chemistry, Electrochemistry Keywords: sodium rechargeable battery; polymer electrolyte; Nafion; cycle stability; electrochemical stability
Online: 18 October 2018 (04:16:01 CEST)
The possibilities of manufacturing batteries with Nafion 117 membranes in the Na+-form intercalated by mixtures of non-aqueous organic solvents used both as electrolyte, separator and binder were investigated. Electrochemical stability of various organic solvent mixtures based on N,N-dimethylacetamide, ethylene carbonate, propylene carbonate, tetrahydrofuran was characterized. It was shown that sodium battery based on Nafion-Na membrane intercalated by mixture of ethylene carbonate ‑ propylene carbonate with Na3V1.9Fe0.1(PO4)3/C positive electrode is characterized by a discharge capacity of ca. 110 mAh g-1 (C/10) at room temperature and shows the ability to cycle for a long time. Batteries with Nafion membrane electrolytes, containing N,N-dimethylacetamide were characterized by capacity fading during cycling, which is due to the interaction of N,N-dimethylacetamide and a negative sodium electrode.
ARTICLE | doi:10.20944/preprints201809.0531.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: energy management system; reserve power; resiliency; battery energy storage system
Online: 27 September 2018 (04:55:24 CEST)
Power system decentralization has been an emerging topic for the past decade in an effort to improve power quality and environment protection via increased integration of renewable energy sources. Towards these objectives, decentralized microgrids have been proposed and thoroughly investigated in terms of technical capabilities and economic performance. In fact, the planning and actual operation of small-scale, decentralized microgrids has started in countries such as Canada, Japan, USA, UK and other countries. It is expected that the research in this area will progress and eventually take over the existing paradigm of large-scale power generation in the future. These small-size decentralized microgrids could be connected with nearby microgrids under normal operating conditions, but under special events, such as natural or man-made disasters, they would be disconnected and run in islanded mode. Under such high impact – low probability events, the microgrid must have resiliency to successfully re-connect with other microgrids and the main grid. In this paper, an Energy Management System (EMS) for a microgrid having a resiliency function, allowing to operate under islanded mode after an accident, is proposed. The proposed tool, called Resilient Energy Management System (ResEMS), aims at procuring reserve power into the microgrid’s Battery Energy Storage System (BESS) effectively, by importing it from the nearby connected power system. The accident is assumed to be a predictable natural disaster, which means that the accident occurrence time, duration and level of damage can be estimated. The proposed ResEMS has been applied to a microgrid comprising of a BESS, a diesel generator and several photovoltaic devices. The simulation results verify its beneficial operation.
ARTICLE | doi:10.20944/preprints201808.0325.v1
Subject: Engineering, Energy & Fuel Technology Keywords: modelling; lead-acid battery; parameter identification; genetic algorithms; experimental validation
Online: 18 August 2018 (06:14:37 CEST)
Accurate and efficient battery modeling is essential to maximize the performance of isolated energy systems and to extend battery lifetime. This paper proposes a battery model that represents the charging and discharging process of a lead-acid battery bank. This model is validated over real measures taken from a battery bank installed in a research center placed at “El Chocó”, Colombia. In order to fit the model, three optimization algorithms (Particle Swarm Optimization, Cuckoo Search, and Particle Swarm Optimization+Perturbation) are implemented and compared, being the last one a new proposal. This research shows that the model with the proposed algorithm is able to estimate and manage the real battery characteristics as SOC and charging/discharging voltage. The comparison between simulations and real measures shows that the model is able to absorb reading problems, signal delays, and scaling errors. The approach we present can be implemented in other types of batteries especially those used in stand-alone systems.
ARTICLE | doi:10.20944/preprints202208.0167.v1
Subject: Chemistry, Electrochemistry Keywords: ring rotating disk electrode (RRDE); voltametric analysis; flow battery, bromide oxidation)
Online: 9 August 2022 (03:32:02 CEST)
We measured the ring collection coefficient of bromide anion oxidation products in a neutral and slightly alkaline medium on a rotating ring-disk electrode (glassy carbon disk, platinum ring) varying the following parameters: disk electrode rotation velocity, sodium bromide concentration, pH of the medium (in the range of 6 – 12), anode current on the disk and the electroreduction potential of the bromide anion oxidation products on the ring. The data obtained is presented via dependences of the cathode ring current to the disk current ratio vs the ring electrode potential. The analysis of the results was carried out by comparing the experimental polarization curves of the ring electrode with the data of cyclic voltammetry in model solutions to determine the electrical activities of various bromine compounds in positive oxidation states. We claim that RRDE method could be used to obtain quantitative and qualitative data on the electrooxidation of bromide ion in neutral and alkaline solutions. For the most effective regeneration of the spent oxidizer the values of pH > 10 and moderate concentrations of NaBr should be used.
ARTICLE | doi:10.20944/preprints202207.0199.v1
Subject: Chemistry, Electrochemistry Keywords: garnet; Li dendrite growth; solid electrolyte; solid state battery; Ga2O3 addition
Online: 13 July 2022 (11:06:32 CEST)
Garnet-type Ta-doped Li7La3Zr2O12 (LLZO) ceramic solid electrolytes with Ga2O3 additive were synthesized via a conventional solid-state reaction process. When the amounts of Ga2O3 additive were below 2 mol %, the sintered sample has a dense structure composed of grains with the averaged size of 5 to 10 μm, while 3 mol % or more Ga2O3 addition causes the significant increase in grain size above several 10 to 100 μm, due to the sintering with large amount of liquid Li-Ga-O phase at high temperature. The highest total (bulk + grain-boundary) ionic conductivity of 1.1 mS cm1 at room temperature was obtained in the sample with 5 mol % Ga2O3 addition. However, in galvanostatic testing of the symmetric cell with Li metal electrodes, this sample was shorted by Li dendrite growth into solid electrolyte at current density below 0.2 mA cm2. The tolerance for Li dendrite growth is maximized in sample sintered with 2 mol % Ga2O3 addition, which was shorted at 0.8 mA cm2 in the symmetric cell. Since the interfacial resistance between Li metal and solid electrolyte was nearly identical among the all samples, the difference in tolerance for Li dendrite growth is mainly attributed to the difference in microstructure of sintered samples depending on the amounts of Ga2O3.
ARTICLE | doi:10.20944/preprints201807.0385.v2
Subject: Social Sciences, Other Keywords: low carbon island; electric motorcycles; green transport; battery exchange; carbon emissions
Online: 5 September 2018 (16:23:53 CEST)
Global warming and climate change have led to extreme changes in climatic conditions in recent years. The Taiwan government designates the construction of the Kinmen County as low carbon islands, to promote the operation of 100 electric motorcycles and battery demonstration. This study combined with island tourism, after boarding the island, visitors can rent electric motorcycles from the passenger service center and coordinate with the island tour map to show the location of the battery exchange points, so as to facilitate the search. During the operation, the amount of electric motorcycle lease is 15,551 times, the total mileage of motor vehicle is 284,404 km, the number of battery exchange is 622 times, the lease income is about NT$900,000. To reduce carbon and economic benefits of the assessment, compared to the motorcycles (50 c.c), electric motorcycles (EM 100) can reduce the carbon emissions by 8,726 kg, reducing energy costs of NT$422,594.
ARTICLE | doi:10.20944/preprints202112.0182.v1
Subject: Materials Science, General Materials Science Keywords: lithium-ion battery; solid-state electrolyte; lithium-ion thermodynamics; solid-state synthesis
Online: 10 December 2021 (13:20:31 CET)
Li7La3Zr2O12Solid-state reaction was used for Li7La3Zr2O12 material synthesis from Li2CO3, La2O3 and ZrO2 powders. Phase investigation by XRD, SEM and EDS methods of Li7La3Zr2O12 were carried out. The molar heat capacity of Li7La3Zr2O12 at constant pressure in the temperature range 298-800 K should be calculated as Cp,m = 518.135+0.599 × T - 8.339 × T−2, where T is absolute temperature, . Thermodynamic characteristics of Li7La3Zr2O12 were determined as next: entropy S0298 = 362.3 J mol-1 K-1, molar enthalpy of dissolution ΔdHLlZO = ˗ 1471.73 ± 29.39 kJ mol−1, the standard enthalpy of formation from elements ΔfH0 = ˗ 9327.65 ± 7.9 kJ mol−1, the standard Gibbs free energy of formation ∆f G0298 = ˗9435.6 kJ mol-1.
ARTICLE | doi:10.20944/preprints202106.0411.v1
Subject: Chemistry, Analytical Chemistry Keywords: lithium-ion battery; silicon nanoparticles; nitrogen-doped graphene; carbon nanofibers; anode material
Online: 15 June 2021 (14:48:47 CEST)
We report a self-assembly synthesis of silicon nanoparticles/nitrogen-doped reduced graphene oxide/ carbon nanofiber (Si@N-doped rGO/CNF) composites as potential high-performance anodes for rechargeable lithium-ion batteries (LIB) through the electrostatic attraction between amino and carboxyl groups. Nitrogen atoms generate a large number of vacancies or defects on the graphite plane, providing additional transmission channels for the diffusion of lithium ions, and improving the conductivity of the electrode. Carbon nanofiber (CNF) can help maintain the stability of the electrode structure and prevent silicon nanoparticles from falling off the electrode, prevent silicon nanoparticles from being directly exposed to the electrolyte, and can form a stable solid electrolyte interface (SEI) film. The three-dimensional conductive structure composed of Si, nitrogen atom-doped reduced graphene oxide (N-doped rGO), and CNF can effectively buffer the volume changes of silicon nanoparticles, shorten the transmission distance of lithium ions (Li+) and electrons, and make the electrode have good conductivity and stability in mechanical properties. In addition, compared with the Si@N-doped rGO and Si/rGO/CNF composite electrode, the Si@N-doped rGO/CNF composite electrode shows good cycle performance and rate capability, and its reversible specific capacity can reach 1418.8 mAh/g. The capacity retention rate is 64.7%, and the coulomb efficiency is 95%.
REVIEW | doi:10.20944/preprints202007.0364.v1
Subject: Materials Science, Other Keywords: metal organic frameworks; catalysts; metal-air battery; solar cells; energy storage; energy
Online: 17 July 2020 (06:03:05 CEST)
The cutting-edge photovoltaic cells are an indispensable part of the ongoing progress of earth-friendly plans for daily life energy consumption. However, the continuous electrical demand that extends to the night time requires a prior deployment of efficient real-time storage systems. In this regard, metal-air batteries have presented themselves as the most suitable candidates for solar energy storage, combining extra lightweight with higher power outputs and promises of longer life cycles. Scientific research over non-precious functional catalysts has always been the milestone and still contributing significantly to exploring new advanced materials and moderating the cost of both complementary technologies. Metal-organic frameworks (MOFs) derived functional materials have found their way to the application as storage and conversion materials, owing to their structural variety, porous advantages, as well as the tunability and high reactivity. In this review, we provide a detailed overview of the latest progress of MOF-based materials operating in metal-air batteries and photovoltaic cells.
ARTICLE | doi:10.20944/preprints201907.0321.v1
Subject: Materials Science, Nanotechnology Keywords: lithium-ion battery; safety; separator; coaxial electrospinning; dual-nozzle; core-shell nanofiber
Online: 28 July 2019 (17:00:49 CEST)
Though the energy density of lithium-ion batteries continues to increase, safety issues related with the internal short-circuit and the resulting combustion of highly flammable electrolyte impede the further development of lithium-ion batteries. It has been well-accepted that a thermal stable separator is important to postpone the entire battery short-circuit and thermal-runaway. Traditional methods to improve the thermal stability of separators includes surface modification and/or developing alternate material systems for separators which may always affect the battery performance negatively. Herein, a thermostable and shrink-free separator with little compromise in battery performance is prepared by coaxial electrospinning and tested. The separator consists of core-shell fiber networks where poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) layer serves as shell and polyacrylonitrile (PAN) as the core. This core-shell fiber network exhibits little or even no shrinking/melting at elevated temperature over 250 °C. Meanwhile, it shows excellent electrolyte wettability and can take large amount of liquid electrolyte three times more than that of conventional Celgard 2400 separator. In addition, the half-cell using LiNi1/3Co1/3Mn1/3O2 as cathode and the aforementioned electrospun core-shell fiber network as separator demonstrates superior electrochemical behavior, stably cycling for 200 cycles at 1 C with a reversible capacity of 130 mAh g-1 and little capacity decay.
ARTICLE | doi:10.20944/preprints201806.0346.v1
Subject: Engineering, Energy & Fuel Technology Keywords: state of charge; state of health; model identification; estimation; lithium-ion battery
Online: 22 June 2018 (05:58:02 CEST)
The accurate monitoring of state of charge (SOC) and state of health (SOH) is critical for the reliable management of lithium-ion battery (LIB) systems. In this paper, the online model identification is scrutinized to achieve high modeling accuracy and robustness, and a model-based joint estimator is further proposed to estimate the SOC and SOH of LIB concurrently. Specifically, an adaptive forgetting recursive least squares (AF-RLS) method is exploited to optimize the estimation alertness and numerical stability, so as to achieve accurate online adaption of model parameters. Leveraging the online adapted battery model, a joint estimator is proposed by combining an open-circuit voltage (OCV) observer with a low-order state observer to co-estimate the SOC and capacity of LIB. Simulation and experimental studies are performed to evaluate the performance of the proposed data-model fusion method. Results suggest that the proposed method can effectively track the variation of model parameters by using the onboard measured current and voltage data. The SOC and capacity can be further estimated in real time with fast convergence, high accuracy and high stability.
REVIEW | doi:10.20944/preprints202201.0135.v1
Subject: Materials Science, Biomaterials Keywords: Wearable sensors; skin-like; heart rate monitoring; continuous glucose monitoring; battery-free sensors
Online: 11 January 2022 (12:18:36 CET)
Currently, old-style personal medicare techniques rely mostly on traditional methods, such as cumbersome tools and complicated processes, which can be time-consuming and inconvenient in some circumstances. Furthermore, such old methods need the use of heavy equipment, blood draws, and traditional bench-top testing procedures. Invasive ways of acquiring test samples can potentially cause patients discomfort and anguish. Wearable sensors, on the other hand, may be attached to numerous body areas to capture diverse biochemical and physiological characteristics as a developing analytical tool. Physical, chemical, and biological data transferred via the skin is used to monitor health in various circumstances. Wearable sensors can assess the aberrant conditions of the physical or chemical components of the human body in real-time, exposing the body state in time, thanks to unintrusive sampling and high accuracy. Most commercially available wearable gadgets are mechanically hard components attached to bands and worn on the wrist, with form factors ultimately constrained by the size and weight of the batteries required for the power supply. Wearable gadgets with “skin-like” qualities are a new type of automation that is only starting to make its way out of research labs and into pre-commercial prototypes. In this paper, we studied the recent advancement in battery-powered wearable sensors established on optical phenomena and skin-like battery-free sensors which brings a breakthrough in wearable sensing automation.
ARTICLE | doi:10.20944/preprints202107.0476.v1
Subject: Engineering, Automotive Engineering Keywords: Battery Energy Storage System; Crowbar; Fault Ride Through Capability; Vector control; Wind turbine
Online: 21 July 2021 (09:51:48 CEST)
Doubly Fed Induction Generator (DFIG) has a stator winding directly coupled with grid. Whereas, rotor winding is connected via a fault-prone back to back power converters. DFIG is known to be vulnerable to the grid faults. In early times, when a fault occurred, these generators were required to disconnect from the grid to secure the generator and power converters. However, due to the increased penetration of wind turbines into the power system, grid operators demanded that the wind turbines remain connected to the grid, as disconnecting them would further disrupt the grid. When a fault at the grid terminal occur, a high stator current is induced which further result in high rotor current. This current will trigger the DC-link voltage to rise. This high currents and DC-link voltage will cause harm to the converters. Thus, in this paper work, the crowbar protection system is employed for protecting the converters against excess energy. Furthermore, the analysis of DFIG is rendered by integrating the crowbar protection with the Battery Energy Storage System (BESS) for a much effective outcome in enhancing machine to drive the fault. MATLAB-Simulink software is used for modeling and simulation. All system parameters are obtained from ADAMA-II Wind Farm.
ARTICLE | doi:10.20944/preprints201907.0201.v2
Subject: Materials Science, Nanotechnology Keywords: lithium ion battery; safety; flame retardant; separator; electrospun fibers; dual-nozzle coaxial electrospinning
Online: 17 September 2019 (12:19:49 CEST)
Lithium-ion batteries have attracted enormous interests recently as promising power sources. However, the safety issue associated with the employment of highly flammable liquid electrolyte impedes the further development of next-generation lithium-ion batteries. Recently, researchers reported the use of electrospun core-shell fiber as the battery separator consisting of polymer layer as protective shell and flame retardants loaded inside as core. In case of a typical battery shorting, the protective polymer shell melts during thermal-runaway and the flame retardants inside would be released to suppress the combustion of the electrolyte. Due to the use of a single precursor solution for electrospinning containing both polymer and flame retardants, the weight ratio of flame retardants is limited and dependent. Herein, we developed a dual-nozzle, coaxial electrospinning approach to fabricate the core-shell nanofiber with a greatly enhanced flame retardants weight percentage in the final fibers. The weight ratio of flame retardants of triphenyl phosphate in the final composite reaches over 60 wt.%. The LiFePO4-based cell using this composite nanofiber as battery separator exhibits excellent flame-retardant property without compromising the cycling stability or rate performances. In addition, this functional nanofiber can also be coated onto commercial separators instead of being used directly as separators.
CASE REPORT | doi:10.20944/preprints201712.0158.v1
Subject: Physical Sciences, Other Keywords: Samsung Note 7 Li-ion, Thermal runaway, Ceramic coating, battery, Tomographic image, Welding characterisation
Online: 21 December 2017 (17:32:42 CET)
Li-ion cell designs, component integrity and manufacturing processes all have critical influence on the safety of Li-ion batteries. Any internal defective features that induce a short circuit, can trigger a thermal runaway: a cascade of reactions, leading to a device fire. As consumer device manufacturers push aggressively for increased battery energy, instances of field failure are increasingly reported. Notably Samsung made a press release in 2017 following a total product recall of their Galaxy Note 7 mobile phone, confirming speculation that the events were attributable to the battery and its mode of manufacture. Recent incidences of battery swelling on the new iPhone 8 have been reported in the media, and the techniques and lessons reported herein may have future relevance. Here we look deeper into the key components of one of these cells and confirm evidence of cracking of electrode material in tightly folded areas, combined with a delamination of surface coating on the separator, which itself is an unusually thin monolayer. We report microstructural information about the electrodes, battery welding attributes and thermal mapping of the battery whilst operational. The findings point to the most likely combination of events and highlights the impact of design features, whilst providing structural considerations most likely to have led to the reported incidences relating to this phone.
ARTICLE | doi:10.20944/preprints201703.0198.v1
Subject: Engineering, Automotive Engineering Keywords: series connected battery string; layered bidirectional equalizer; power inductor; dynamic adjustment of equalization path
Online: 27 March 2017 (10:41:03 CEST)
To eliminate the influence of the inconsistency on the cycle life and the available capacity of the battery pack, and improve the balancing speed, a novel inductor-based layered bidirectional equalizer (IBLBE) is proposed. The equalizer is composed of the bottom balancing circuits and the upper balancing circuits, and the two layer circuits both consist of a plurality of balancing sub-circuits, which allow the dynamic adjustment of equalization path and equalization threshold. The battery string is modularized by layered balancing circuits to realize fast active equalization, especially for long battery strings. By controlling the bottom balancing circuits, the individual cells can be balanced in each module. At the same time, the equalization between battery modules can be realized by controlling the upper balancing circuits. Simulation and experimental results demonstrate that the proposed equalizer can achieve fast active equalization for a long battery string, and has the characteristics of multi balancing path, large balancing current and high accuracy. The advantages of the proposed equalizer are further verified by a comparison with existing active equalizer.
ARTICLE | doi:10.20944/preprints201906.0226.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: motorised mobility; average distances; international comparison; future automobiles; automotive companies; battery autonomy (range); economic analysis
Online: 22 June 2019 (15:59:01 CEST)
This paper aims at providing a multisource data analysis, including direct data collection, focussed on daily average distances covered with motorised mobility. Its results can be used as a basis for policies involving a shift towards new propulsions, electric motors or hybrid electric vehicles (HEV) for road vehicles. A number of variables influence the propensity of drivers to acquire or use electric traction, even the option of plug-in hybrid electric vehicles (PHEV). This paper addresses one of such variable: the compliancy of electric traction regarding both hybrid plug-in solutions and full-electric vehicles, in addition to the autonomy of batteries (range), with the daily travels by road vehicles, mainly by automobiles. We want to understand whether the constraints leading towards a greater independence from crude oil rather than constraints concerning emissions, mainly in urban contexts, might be compliant with the habitual daily trips of drivers. We also want to understand if these daily trips have varied much during recent years and the consequences they may have on operational costs of plug-in automobiles. We are well aware that the average distances do not represent the actual daily runs of vehicles; yet similar distributions of daily distances for different case studies indicate that a high percentage of trips respond to certain features. After introducing a general overview of road-motorised mobility in Italy, the paper compares data from other studies to provide an indication of average daily driving distances. This reveals how different recent analyses converge on a limited range of average road distances covered daily by Italians, which is compliant with ranges allowed by electric batteries, provided that their low energy density in comparison with that of oil-derived fuels do not imply a significant increase in vehicle mass. Subsequently, average distances in some EU Countries are taken from the literature, and the results are also compared with U.S. data. The study extends the analysis of trends on the use of automobiles and road-vehicles to the international context by also addressing average daily distances covered for freight transport in some EU Countries, thereby providing a further basis for comparison and for understanding whether the daily motorised mobility can be considered as a stable phenomenon. Finally, an analysis is provided of the economic operational advantages from using plug-in vehicles. The main aim of this paper is thereafter to investigate the average daily motorised mobility of single vehicles – so not an aggregated motorised mobility as collected by some statistics – by using private motorised vehicles in Italy, with related trends; thereafter, to compare these data with those obtained from other countries, making use of both existing research studies and directly collected data; the final aim is to understand both the compliance of daily activities based on the use of automobiles with the autonomy of batteries (range) and to calculate some economic outcomes.
ARTICLE | doi:10.20944/preprints201905.0283.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: control; current mode control; voltage control; transfer function; power converter; soft-switching converter; battery charging;
Online: 23 May 2019 (12:58:27 CEST)
This paper presents a control algorithm for soft-switching series LC converters. The conventional voltage-to-voltage controller is split into a master and a slave controller. The master controller implements constant-current-constant-voltage (CCCV) control, required for demanding applications, i.e. lithium battery charging or laboratory power supplies. It defines the set-current for the open-loop current slave controller, which generates the PWM parameters. The power supply achieves fast large-signal responses, e.g. from 5 V to 24 V, where 95% of the target value is reached in less than 400 µs. The design is evaluated extensively in simulation and on a prototype. A consensus between simulation and measurement is achieved.
ARTICLE | doi:10.20944/preprints201904.0016.v1
Subject: Chemistry, Electrochemistry Keywords: Li-ion battery; electrode; porous structure; virtual structure; machine learning; simulation; physico-chemical model; optimization
Online: 1 April 2019 (13:35:13 CEST)
We have proposed a data-driven approach for designing mesoscale porous structures of Li-ion battery electrode with three-dimensional virtual structures and machine learning techniques. Over 2,000 artificial 3D structures assuming positive electrode composed of random packed spheres as active material particles are generated, and charge/discharge resistance has been evaluated using simplified Physico-chemical model. In this model, resistance from Li diffusion in active material particles (diffusion resistance), transfer resistance of Li+ in electrolyte (electrolyte resistance) and reaction resistance on the interface between active material and electrolyte are simulated based on mass balance of Li, Ohm’s law in and linearized Butler-Volmer equation, respectively. Using these simulation results, regression models via Artificial Neural Network (ANN) have been created in order to predict charge/discharge resistance from porous structure features. In this study, porosity, active material particle size and volume fraction, pressure in the compaction process, electrolyte conductivity, and binder volume fraction are adopted as features, associated with controllable process parameters for manufacturing battery electrode. As results, the predicted electrode resistance by ANN regression model is good agreement with the simulated values. Furthermore, sensitivity analysis and optimization of the process parameters have been carried out. The proposed data-driven approach could be a solution as a guiding principle for manufacturing battery electrode.
ARTICLE | doi:10.20944/preprints201810.0222.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Lithium ion battery pack; state of charge; square root; unscented Kalman filter; adaptive covariance matching
Online: 10 October 2018 (14:45:10 CEST)
The state of charge estimation is an important part of the battery management system, the estimation accuracy of which seriously affects the working performance of the lithium ion battery pack. The unscented Kalman filter algorithm has been developed and applied to the iterative calculation process. When it is used to estimate the SOC value, there is a rounding error in the numerical calculation. When the sigma point is sampled in the next round, an imaginary number appears, resulting in the estimation failure. In order to improve the estimation accuracy, an improved adaptive square root - unscented Kalman filter method is introduced which combines the QR decomposition in the calculation process. Meanwhile, an adaptive noise covariance matching method is implied. Experiments show that the proposed method can guarantee the semi-positive and numerical stability of the state covariance, and the estimation accuracy can reach the third-order precision. The error remains about 1.60% under the condition of drastic voltage and current changes. The conclusion of this experiment can provide a theoretical basis of the state of charge estimation in the battery management of the lithium ion battery pack.
ARTICLE | doi:10.20944/preprints201809.0594.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: adaptive neuro-fuzzy inference system; battery energy storage; photovoltaic unit; power demand; peak power curtailment
Online: 30 September 2018 (04:56:58 CEST)
One of the most crucial and economically beneficial tasks for energy customer is peak load curtailment. On account of the fast response of renewable energy resources (RERs) such as photovoltaic (PV) units and battery energy storage system (BESS), this task is closer to be efficiently implemented. Depends on the customer peak load demand and energy characteristics, the feasibility of this strategy may warry. When adaptive neuro-fuzzy inference system (ANFIS) is exploited for forecasting, it can provide many benefits to address the above-mentioned issues and facilitate its easy implementation, with short calculating time and re-trainability. This paper introduces a data driven forecasting method based on fuzzy logic for optimized peak load reduction. First, the amount of energy generated by PV is forecasted using ANFIS which conducts output trend, and then, the BESS capacity is calculated according to the forecasted results. The trend of the load power is then decomposed in Cartesian plane into two parts, left and right from load peak, searching for BESS capacity equal. Network switching sequence over consumption is provided by a fuzzy logic controller (FLC) with respect to BESS capacity and PV energy output. Finally, to prove the effectiveness of the proposed ANFIS-based peak shaving method, offline digital time-domain simulations have been performed on a real-life practical test micro grid system in MATLAB/Simulink environment and the results have been experimentally verified by testing on a practical micro grid system with real-life data obtained from smart meter and also, compared with several previously-reported methods.
COMMUNICATION | doi:10.20944/preprints201901.0072.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Electroconductive additive; Sulfur cathode; Aluminum-foam current collector; Areal capacity; C-rate capability; Lithium-ion battery
Online: 8 January 2019 (15:19:26 CET)
Various types of electroconductive additives were evaluated for high C-rate capability in an attempt to extend practical application of high-areal-capacity lithium–sulfur batteries that employ an aluminum-foam current collector. Carbon nanofibers (CNFs) were found to be the most effective additive, with the ability to attain a high-sulfur-loading of 40 mg cm−2. A CNF-containing cell exhibited gravimetric capacities of 1094 and 758 mAh gsulfur−1 (46.8 and 32.4 mAh cm−2) at 0.05 and 0.1 C-rate, respectively, in an ether-based electrolyte. Because a CNF-containing slurry exhibits low viscosity even at a high solid ratio, it could be filled into the aluminum foam. Additionally, a lithium–sulfur battery with high-sulfur-loading had an energy density of ~120 Wh kg−1, a value that was calculated from the weight of the components of the cathode, anode, current collectors, electrolyte, and separator. Assuming that the amount of electrolyte decreases and that the energy density of cells accumulate, a theoretical energy density of 522 Wh kg−1 was estimated. Moreover, it was found that even if a high-areal-capacity was achieved, the discharge capacity converged at a high C-rate, unless there was an improvement in ion diffusion in the bulk electrolyte. This is considered a limitation of sulfur cathodes with high-sulfur-loading.
ARTICLE | doi:10.20944/preprints201608.0148.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: ac–dc power converters; battery chargers; dual active bridge; DAB; optimal design; power MOSFETs; single-stage
Online: 15 August 2016 (11:06:09 CEST)
The growing attention for plug-in electric vehicles, and the associated high-performance demands, have initiated a development trend towards highly efficient and compact on-board battery chargers. These isolated ac-dc converters are most commonly realized using two conversion stages, combining a non-isolated power factor correction (PFC) rectifier with an isolated dc-dc converter. This, however, involves two loss stages and a relatively high component count, limiting the achievable efficiency and power density and resulting in high costs. In this paper a single-stage converter approach is analyzed to realize a single-phase ac-dc converter, combining all functionalities into one conversion stage and thus enabling a cost-effective efficiency and power density increase. The converter topology consists of a quasi-lossless synchronous rectifier followed by an isolated dual active bridge (DAB) dc-dc converter, putting a small filter capacitor in between. To show the performance potential of this bidirectional, isolated ac-dc converter, a comprehensive design procedure and multi-objective optimization with respect to efficiency and power density is presented, using detailed loss and volume models. The models and procedures are verified by a 3.7 kW hardware demonstrator, interfacing a 400 V dc-bus with the single-phase 230 V, 50 Hz utility grid. Measurement results indicate a state-of-the-art efficiency of 96.1% and power density of 2.2 kW/dm3, confirming the competitiveness of the investigated single-stage DAB ac-dc converter.
ARTICLE | doi:10.20944/preprints202007.0673.v1
Subject: Engineering, Automotive Engineering Keywords: life cycle assessment; agent-based traffic simulation; battery electric vehicles; sustainability; urban transportation; urban mobility; environmental engineering
Online: 28 July 2020 (10:13:30 CEST)
The transport sector in Germany causes one-quarter of energy-related greenhouse gas emissions. One potential solution to reduce these emissions is the use of battery electric vehicles. Although a number of life cycle assessments have been conducted for these vehicles, the influence of a transport system wide transition has not been researched sufficiently. Therefore, we developed a method which combines life cycle assessment with an agent-based transport simulation and synthetic electric, diesel and gasoline powered vehicle models. We use the transport simulation to obtain the number of vehicles, their lifetime mileage and road-specific consumption. Subsequently we analyze the product systems’ vehicle production, use phase and End-of-Life. The results are scaled depending on the covered distance, the vehicle weight and the consumption for the whole life cycle. The results indicate that the sole transition of drive trains is insufficient to significantly lower the greenhouse gas emissions. However, sensitivity analyses demonstrate that there is a considerable potential to reduce greenhouse gas emissions with higher shares of renewable energies, a different vehicle distribution and a higher lifetime mileage. The method facilitates the assessment of the ecological impacts of the complete car based transportation in urban agglomerations and is able to analyze different transport sectors.
ARTICLE | doi:10.20944/preprints201705.0116.v1
Subject: Engineering, Mechanical Engineering Keywords: thermal runaway; big-data platform; battery systems; electric vehicles; National Service and Management Center for Electric Vehicles
Online: 16 May 2017 (03:18:57 CEST)
This paper presents a thermal runaway prognosis scheme based on the big-data platform and entropy method for battery systems in electric vehicles. It can simultaneously realize the diagnosis and prognosis of thermal runaway caused by the temperature fault through monitoring battery temperature during vehicular operations. A vast quantity of real-time voltage monitoring data was collected in the National Service and Management Center for Electric Vehicles (NSMC-EV) in Beijing to verify the effectiveness of the presented method. The results show that the proposed method can accurately forecast both the time and location of the temperature fault within battery packs. Furthermore, a temperature security management strategy for thermal runaway is proposed on the basis of the Z-score approach and the abnormity coefficient is set to make real-time precaution of temperature abnormity.
ARTICLE | doi:10.20944/preprints201805.0368.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: battery energy storage system (BESS); PV; micro CHP; microgrid; islanded operation; distribution network; network outage; reliability; underground cable
Online: 25 May 2018 (12:06:44 CEST)
Microgrids can be used for securing power supply during network outages. Underground cabling of distribution networks is another effective, but conventional and expensive alternative to enhance reliability of power supply. This paper presents firstly an analysis method for the determination of microgrid power supply adequacy during islanded operation, and secondly, a comparison method for overall cost calculation of microgrids vs. underground cabling. The microgrid power adequacy during a rather long network outage is required in order to indicate high level of reliability of supply. The overall cost calculations consider the economic benefits and costs incurred combined for both the distribution network company and the consumer. Whereas the microgrid setup determines the islanded operation power adequacy and thus the reliability of supply, the economic feasibility results from the normal operations and services. The methods are illustrated by two typical, and even critical, case studies in rural distribution networks: an electric-heated detached house and a dairy farm. These case studies show that even in case of a single consumer, a microgrid option could be more economical than network renovation by underground cabling of a branch in order to increase reliability.
ARTICLE | doi:10.20944/preprints202009.0418.v1
Subject: Engineering, Automotive Engineering Keywords: large sized lithium-ion battery; physic-based model; life prediction; scale-up model; reduced order cell model; electric vehicles
Online: 18 September 2020 (04:29:49 CEST)
Large lithium-ion batteries (LIBs) in electric vehicles and energy storage systems demonstrate different performance and lifetime compared to small LIB cells, owing to the size effects generated by the electrical configuration and property imbalance. However, the calculation time for performing life predictions with three-dimensional (3D) cell models is undesirably long. In this paper, a lumped cell model with equivalent resistances (LER cell model) is proposed as a reduced order model of the 3D cell model, which enables accurate and fast life predictions of large LIBs. The developed LER cell model is validated via the comparisons with results of the 3D cell models by simulating a 20-Ah commercial pouch cell (NCM/graphite) and the experimental values. In addition, the LER cell models are applied to different cell types and sizes, such as a 20-Ah cylindrical cell and a 60-Ah pouch cell.
ARTICLE | doi:10.20944/preprints201804.0056.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: demand-side management; peak demand control; dynamic-interval density forecast; stochastic optimization; dimension reduction; battery energy-storage system (BESS)
Online: 4 April 2018 (08:37:59 CEST)
A Demand-side management technique are deployed along with battery energy-storage systems (BESSs) to lower the electricity cost by mitigating the peak load of a building. Most of the existing methods rely on manual operation of the BESS, or even an elaborate building energy-management system resorting to a deterministic method that is susceptible to unforeseen growth in demand. In this study we propose a real-time optimal operating strategy for BESS based on density demand forecast and stochastic optimization. This method takes into consideration uncertainties in demand when accounting for an optimal BESS schedule, making it robust compared to the deterministic case. The proposed method is verified and tested against existing algorithms. Data obtained from a real site in South Korea is used for verification and testing. The results show that the proposed method is effective, even for the cases where the forecasted demand deviates from the observed demand
ARTICLE | doi:10.20944/preprints202001.0054.v1
Subject: Engineering, Energy & Fuel Technology Keywords: lithium-ion (Li-ion) battery; remaining useful life (RUL); health indicator (HI); generalized regression neural network (GRNN); non-linear autoregressive (NAR)
Online: 7 January 2020 (09:17:28 CET)
The remaining capacity can only be measured with offline method. This brings great challenge for the online prediction of Li-ion battery’s RUL. A novel online prediction method for Li-ion battery’s RUL was proposed, which is based on multiple health indicators (HIs) and can be derived from the batteries’ historical operation data. Firstly, four indirect HIs were built according to the battery’s operation current, voltage and temperature data respectively. On that basis, a generalized regression neural network (GRNN) was developed to estimate the battery’s remaining capacity, and the non-linear autoregressive approach (NAR) was utilized to predict the battery’s RUL based on the estimated capacity value. Furthermore, to reduce the interference, twice wavelet denoising were performed with different thresholds. A case study is conducted with a NASA battery dataset to demonstrate the effectiveness of the method. The result shows that the proposed method can obtain Li-ion batteries’ RUL effectively.
CONCEPT PAPER | doi:10.20944/preprints202206.0431.v1
Subject: Mathematics & Computer Science, Other Keywords: Formal Specification; Microgrid; Battery Energy Storage Systems; Software Engineering; Plug-in Hybrid Electric Vehicle; Modeling; Renewable Energy; Safety-Critical systems; Microgrid Community
Online: 30 June 2022 (15:55:17 CEST)
Electrical microgrids are deemed to be the future of modern power systems. Microgrids are sophisticated, decentralized, and self-sufficient small-scale power systems consisting of various resources ranging from wind turbines, solar photovoltaics, electric vehicles, smart energy storage, and complex communication infrastructure. However, renewable energy sources such as solar photovoltaics and wind-based generators are highly intermittent, and if not appropriately planned, they can compromise the stability of the grid. Formal methods can define and analyze the functionality and behavior of any system and show if the system design is correct before the actual system is implemented. Although formal methods have been around for many years, it is surprising that little to none are utilized in the design of safety-critical electrical power systems. Currently, in modeling microgrids, few to no attempts of formalization are being used to improve the design reliability and reduce system operating costs and time. This work demonstrates how complex systems such as microgrids can be modeled elegantly using a formal specification method. In this work, the Z state-based formal specification language (Z-Method) is used to model and verify microgrid designs. In this work, 3-interconnected microgrid systems with a high penetration level of solar and wind-based renewable energy sources with plugin hybrid electric vehicles (PHEV) as battery energy storage systems (BESS) are modeled using the Z-method. To the best of authors, the knowledge presented formal method is one of the first reported attempts in modeling microgrid communities using Software Engineering formalism.
ARTICLE | doi:10.20944/preprints202003.0379.v1
Subject: Engineering, Energy & Fuel Technology Keywords: vanadium redox flow battery; power density; limiting current; cell geometry; mass transfer; electrolyte mixing; static mixer; industrial design; multidisciplinary research; energy transitions
Online: 26 March 2020 (01:51:17 CET)
The world is moving to the next phase of the energy transition with high penetrations of renewable energy. Flexible and scalable redox flow battery (RFB) technology is expected to play an important role in ensuring electricity network security and reliability. Continuous performance improvements will further enhance their value by reducing parasitic losses and maximizing available energy conversion over broader operating conditions. Concentration overpotentials from poor internal reactant distribution at high and low states of charge (SOC) limit power densities and are thus an important area of investigation. However, efforts to address these coupled electrochemical phenomena can compromise mechanical performance. Modelling and simulation of cell design innovations have shown it is possible to reduce losses from pump energy while increasing the availability of active species where required. The combination of wedge-shaped cells with static mixers investigated in this paper can reduce pressure drop and improve energy efficiency. Toroidal vanadium redox flow battery (VRB/VRFB) designs incorporating this innovation are presented for further development to improve community engagement with the technology.
ARTICLE | doi:10.20944/preprints202111.0234.v1
Subject: Materials Science, General Materials Science Keywords: niobium tungsten oxide; pentagonal tunnels; tetragonal tungsten bronze; high-angle annular dark field detector; scanning transmission electron microscopy; HAADF-STEM; twinning; superstructure, battery material.
Online: 12 November 2021 (15:17:48 CET)
The evaluation of HAADF-STEM images of a sample with the composition Nb18W16O93 provided new insights in its real structure. The basic structure comprises an intact octahedral framework of the tetragonal tungsten bronze (TTB) type. The partial occupation of the pentagonal tunnels (PT) by metal-oxygen strings determines the oxygen to metal ratio (O/SM with M = Nb,W). For a large area, the O/SM was determined to be 2.755 which is smaller than the value of Nb18W16O93 which is O/SM = 2. 735. To a large extent, the threefold TTB superstructure structure of Nb8W9O47 with a high oxygen content is present (O/SM = 2.765). In addition, a new fourfold TTB superstructure was found in small domains: Nb12W11O63 with an O/SM = 2.739 obviously accommodates a part of the sample’s metal excess compared to the stable phase Nb8W9O47.
ARTICLE | doi:10.20944/preprints202012.0312.v1
Subject: Engineering, Automotive Engineering Keywords: Bayesian Network; Root Cause Analysis; Failure Mode and Effect Analysis; Lithium-Ion 15 Battery Cell; Failure Propagation; Multi-Stage Production; Manufacturing Process; Process Optimization; Scrap Rate
Online: 14 December 2020 (09:31:30 CET)
The production of lithium-ion battery cells is characterized by a high degree of complexit due to numerous cause-effect relationships between process characteristics. Knowledge about the multi-stage production is spread among several experts, rendering tasks such as failure analysis challenging. In this paper, a method is presented, which includes expert knowledge acquisition in production ramp-up by combining Failure Mode and Effects Analysis (FMEA) with a Bayesian Network. We show the effectiveness of this holistic method by building up a large scale, cross-process Bayesian Failure Network in lithium-ion battery production. Using this model, we are able to conduct root cause analyses as well as analyses of failure propagation. The former support operators in identifying root causes once a cell possesses a specific failure by calculating most-probable explanations matched to the individual battery cell data. The latter enable us to analyze propagation of failures and deviations in the production chain and thus provide support for placement of quality gates, leading to a significant reduction in scrap rate. Moreover, it gives an insight into which process steps are key drivers for which final product characteristics.
ARTICLE | doi:10.20944/preprints202012.0121.v1
Subject: Engineering, Automotive Engineering Keywords: Decarbonization Methodology; Urban Traffic; Agent-Based Transport Simulation; Life Cycle Assessment; Sustainability; Total Cost of Ownership; Charging Concepts; Conceptual Vehicle Design; Battery Electric Vehicles; Vehicle Routing Problem
Online: 6 December 2020 (18:16:16 CET)
This paper presents a new methodology to derive and analyze strategies for a fully decarbonized urban transport system which combines conceptual vehicle design, a large-scale agent-based transport simulation, operational cost analysis, and life cycle assessment for a complete urban region. The holistic approach evaluates technical feasibility, system cost, energy demand, transportation time and sustainability-related impacts of various decarbonization strategies. In contrast to previous work, the consequences of a transformation to fully decarbonized transport system scenarios are quantified across all traffic segments, considering procurement, operation and disposal. The methodology can be applied to arbitrary regions and transport systems. Here, the metropolitan region of Berlin is chosen as a demonstration case. First results are shown for a complete conversion of all traffic segments from conventional propulsion technology to battery electric vehicles. The transition of private individual traffic is analyzed regarding technical feasibility, energy demand and environmental impact. Commercial goods, municipal traffic and public transport are analyzed with respect to system cost and environmental impacts. We can show a feasible transition path for all cases with substantially lower greenhouse gas emissions. Based on current technologies and today’s cost structures our simulation shows a moderate increase in total systems cost of 13-18%.
REVIEW | doi:10.20944/preprints201705.0090.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Electric Vehicle; internal combustion engine; greenhouse gas; optimization techniques; Battery Electric Vehicle (BEV); Hybrid Electric Vehicle (HEV); Plug-in Hybrid Electric Vehicle (PHEV); Fuel Cell Electric Vehicle (FCEV).
Online: 10 May 2017 (17:44:51 CEST)
Electric vehicles (EV) are getting more commonplace in the transportation sector in recent times. As the present trend suggests, this mode of transport is likely to replace the internal combustion engine (ICE) vehicles in near future. Each of the main EV components has a number of technologies that are currently in use or can become prominent in the future. EVs can cause significant impacts on the environment, power system, and other related sectors. The present power system can face huge instabilities with enough EV penetration; but with proper management and coordination, EVs can be turned into a major contributor to the successful implementation of smart grid. There are possibilities of immense environmental benefits as well, as the EVs can extensively reduce the greenhouse gas emission from the transportation sector. However, there are some major obstacles for EVs to overcome before replacing the ICE vehicles totally. This paper is focused on reviewing all the useful data available on EV configurations, energy sources, motors, charging techniques, optimization techniques, impacts, trends, and possible directions of future developments. Its objective is to provide an overall picture of the current EV technology and ways of future development to assist in future researches in this sector.
ARTICLE | doi:10.20944/preprints201806.0254.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: demand-side management; peak demand control; dynamic-interval density forecast; stochastic optimization; dimension reduction; battery energy-storage system (BESS), plugged-in electric vehicles (PEV); vehicle-to-grid (V2G); building energy-management systems (BEMS)
Online: 15 June 2018 (13:01:42 CEST)
This study purposes the use of plug-in electric vehicles for demand side management (DSM) considering uncertainties in demand as well as uncertainties due to mobility of PEV to mitigate peak demand. The solution also seeks to reduce electric cost in addition to reducing the effects of greenhouse gases. In recent years DSM using distributed storage system such as battery energy management system (BESS) and plugged-in electric vehicles (PEV) have become very prevalent with most implementations resorting to deterministic load forecast. These methods do not consider the potential growth in demand making their solutions less robust. In this study we propose a real-time density demand forecast and stochastic optimization for robust operation of PEV for a building. This method accounts for demand uncertainties in addition to uncertainties in mobile energy storage as found in PEV, making the resulting solution robust as compared to the deterministic case. A case study on a real site in South Korea is used for verification and testing. The proposed study is verified and tested against existing algorithms. The result verifies the effectiveness of the proposed approach