Flexible low-grade energy utilization devices based on high-performance thermoelectric polyaniline/tellurium nanorod hybrid films

With the growing global energy crisis, new methods of energy development and utilization have become the main solutions to energy issues. Solution based polymer thermoelectric (TE) generation technologies provide a low-cost and eco-friendly means of direct energy conversion from low-grade heat to electricity. By integrating high Seebeck coefficient tellurium nanorods with the conducting polymer polyaniline (PANI) to form PANI/Te hybrid films, well-matched nanoscale interfaces improve carrier transport properties yet keep the thermal conductivity at a rather low level of 0.2 W m^-1 K^-1. Therefore, the originally mutual restricted parameters (electrical conductivity, Seebeck coefficient and thermal conductivity) finally reach an increase in the ZT value. The maximum power factor of the PANI/Te (70 wt%) composite film reached 105 μW m^-1 K^-2 at room temperature and further reached up to 146 μW m^-1 K^-2 at 463 K, and the ZT value increased from 0.156 at room temperature to 0.223 at 390 K, which are the highest values reported so far for PANI based TE materials. A screen-printing process was employed to fabricate in-plane power generation devices based on the high-performance PANI/Te hybrid films. A prototype device with 10 legs of PANI/Te-Ag could provide a maximum output voltage and output power of 29.9 mV and 0.73 μW, respectively at temperature gradient 40 K. The results evidently demonstrate a promising and economic route for conducting polymers to be applied in low-grade energy conversion utilization.