Gram-scale polymer-based thermoelectric module for charging Li-ion batteries

Organic thermoelectric devices are promising for charging Li-ion batteries in state-of-art sensors and communication devices. Herein, we report the design and fabrication of a gram-scale polymer -based thermoelectric module prepared by lamination of ultrathin half-dried poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) films with Ni foils. The hot pressing of a half-dried PEDOT/PSS film increases the film electrical conductivity and decreases its contact resistance. Such devices exhibit a power density of 72 mW/cm2 at 100 degrees C under natural cooling conditions in the absence of a heat sink. A 5 g device is capable of fully charging a commercial Li-ion battery (Nichicon SLB03070LR35) within 2 days. The manufactured organic thermoelectric device can be used instead of a CR2032 coin cell to power commercial sensors of acceleration, geomagnetism, temperature, humidity, atmospheric pressure, and illuminance. The manufactured devices exhibit excellent stability for over 2 months under continuous operation conditions. This work highlights the potential of organic thermo-electric devices for energy harvesting.(c) 2022 Elsevier Ltd. All rights reserved.