Paper-based thermoelectric generator based on multi-walled carbon nanotube/carboxylated nanocellulose

Cellulose is the most abundant polymer material in nature. After being produced on the nanometer scale, it is widely used in research on flexible energy storage equipment and power supply equipment. Therefore, this study has prepared a nanocomposite thermoelectric material based on multi-walled carbon nanotube (MWCNT) and carboxylated nanocellulose fiber (C-CNF) and obtained a free-standing paper-based thermoelectric generator (TEG) through a simple printing method. The equipment exhibits excellent mechanical flexibility. At the same time, the thermal conductivity is significantly reduced under the dual effects of paper and C-CNF (is reduced to 0.02–0.09 W/mK). The TEG prototype has four P-shaped feet. Under a temperature gradient of 70 K, the open circuit voltage is 3.3 mV, and the output power is up to 3.7 nW. This work not only confirms the improvement of MWCNT thermoelectric performance by C-CNF but also provides a new strategy for the preparation of low-cost and environmentally friendly thermoelectric generators.