Jang, E.; Banerjee, P.; Huang, J.; Holley, R.; Gaskins, J.T.; Hoque, M.S.B.; Hopkins, P.E.; Madan, D. Thermoelectric Performance Enhancement of Naturally Occurring Bi and Chitosan Composite Films Using Energy Efficient Method. Electronics2020, 9, 532.
Jang, E.; Banerjee, P.; Huang, J.; Holley, R.; Gaskins, J.T.; Hoque, M.S.B.; Hopkins, P.E.; Madan, D. Thermoelectric Performance Enhancement of Naturally Occurring Bi and Chitosan Composite Films Using Energy Efficient Method. Electronics 2020, 9, 532.
Jang, E.; Banerjee, P.; Huang, J.; Holley, R.; Gaskins, J.T.; Hoque, M.S.B.; Hopkins, P.E.; Madan, D. Thermoelectric Performance Enhancement of Naturally Occurring Bi and Chitosan Composite Films Using Energy Efficient Method. Electronics2020, 9, 532.
Jang, E.; Banerjee, P.; Huang, J.; Holley, R.; Gaskins, J.T.; Hoque, M.S.B.; Hopkins, P.E.; Madan, D. Thermoelectric Performance Enhancement of Naturally Occurring Bi and Chitosan Composite Films Using Energy Efficient Method. Electronics 2020, 9, 532.
Abstract
The main aim of this work is to report an alternative energy efficient technique of fabricating flexible thermoelectric generators (TEGs) using printable ink. In this process, we have fabricated thermoelectric (TE) composite thick film and we are experimenting several ways to overcome the challenges of conventional and additive manufacturing methods. Two different mesh sizes of n-type bismuth particle, various binder to thermoelectric (TE) material weight ratio, and two different pressure (200 MPa and 300 MPa) were employed for optimizing the thermoelectric properties of TE composite films. We are also exploring naturally occurring chitosan as a binder. Dimethyl sulfoxide (DMSO) dissolved chitosan was used for the binder and less than 0.2 wt% of chitosan was sufficient for the fabrication of TE inks and composite films. Low energy intensive curing process was employed to evaporate the solvent from the drop casted inks. External uniaxial pressure not only eliminated high energy intensive curing processes but also increased the packing density of the film by removing pores and voids in the chitosan-bismuth composite film. The microstructure analysis reveals that bulk-like structure, which rarely has voids, pores and grain boundaries, was observed in the composite films pressed at sufficiently high pressures. The highest performing composite film was obtained with the conditions of 1:2000 binder to bismuth weight ratio, 100 mesh of particle size, and 300 MPa of pressure. The best performing bismuth chitosan composite film pressed at 300 MPa had the power factor as 4009 ± 391 μW/m·K2 with high electrical conductivity value of 7337 ± 522 S/cm. The measured thermal conductivity of the best performing chitosan-bismuth composite film was 4.4 ± 0.7 W/m·K and the figure of merit calculated from the thermal conductivity was 0.27 at room temperature.
Keywords
Bismuth; Chitosan; pressure; thermoelectric; composite film
Subject
Engineering, Electrical and Electronic Engineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
