Polyaniline/SWCNT composite films prepared via the solvent-induced strategy for flexible energy harvesting

Abstract

Preparing high-performance, stable, and flexible thermoelectric materials via a simple method is significant for promoting practical applications of the thermoelectric system. Herein, a facile solvent-induced strategy has been developed to prepare a polyaniline (PANI)/single-walled carbon nanotube (SWCNT) flexible film without using any small-molecule dopants, which are relatively unstable. For the N,N-dimethylformamide (DMF) solvent-induced composite films, a high power factor of 207.3 μW m⁻¹ K⁻² has been obtained at room temperature when the content of SWCNTs is 90 wt% due to the induction effect of the SWCNTs and charge transfer effect between PANI and the SWCNTs. Furthermore, the effect of temperature on TE performance in the PANI-based nanocomposites has been investigated via in situ structural analysis. A prototype device with eight pieces of PANI/SWCNT films connected by silver wires has been fabricated and its maximum output power reaches 1628 μW at a temperature difference of 66.8 K, which corresponds to a normalized maximum output power density of 27.4 μW m⁻¹ K⁻². This work imparts a deeper understanding of PANI-based nanocomposites and has great significance in practical applications for wearable energy harvesting.