PEDOT thermoelectric composites with excellent power factors prepared by 3-phase interfacial electropolymerization and carbon nanotube chemical doping

Abstract

Compared with common chemical oxidation polymerization reactions, the electrochemical polymerization method has seldom been employed for the preparation of high-performance polymer thermoelectric composites, although it has obvious advantages of film product and highly tunable functions. Herein, we reported a novel preparation strategy, i.e. the combination of dynamic 3-phase interfacial electropolymerization for poly(3,4-ethylenedioxythiophene) (PEDOT) and the chemical doping of single-walled carbon nanotubes (SWCNTs), to fabricate flexible films of their thermoelectric composites. The acid-doped SWCNTs (a-SWCNTs) displayed a significantly enhanced electrical conductivity and a reduced Seebeck coefficient. The PEDOT/a-SWCNT composites exhibit excellent power factors with the maxima of 350.0 ± 47.6 μW m⁻¹ K⁻² at room temperature, and even as high as 510.2 μW m⁻¹ K⁻² at 412 K. More importantly, the thermoelectric performance can be conveniently tuned by various parameters, such as the a-SWCNT content, and electropolymerization conditions including the type and loading of the PEDOT counter ions. The present study proposes a new design strategy to fabricate high-performance polymer thermoelectric composites and facilitates the application of organic/inorganic thermoelectric composites.