Thermoelectric properties of conducting polyaniline/graphite composites

HClO₄-doped polyaniline/graphite composites were prepared by mechanical ball milling and cold pressing. The thermoelectric properties for the composites were investigated as a function of graphite concentration. The thermal conductivity (К) increases slightly with increasing graphite content but the electric conductivity(σ) as well as the Seebeck coefficient (S) increases remarkably, which leads to an obvious enhancement in the figure of merit for the composites. The ZT of the composite with graphite concentration of 50 wt % was calculated to be 1.37 × 10^− 3 at 393 K, which was at least 10000 times greater than that of the HClO₄-doped polyaniline without graphite (1.13 × 10^− 7). This work suggests a new method to improve thermoelectric properties of conducting polymers.