Ca3Co409/polyaniline bulk composites have been successfully fabricated by ball-milling and hot-pressing method. Our results indicate that the Seebeck coefficient can be increased nearly by 400% with adding 15 wt% 0a3Co409 to the polyaniline. The thermal conductivity changes slightly with increasing filler content. The highest figure of merit, ZT can reach 5× 10-4 at 329 K for these bulk composites, which is almost 50 times larger than that of pure polyaniline, suggesting that the polymer-thermoelectric oxide composites are promising candidates for light-weight, low-cost and non-toxic thermoelectric applications.
The efficiency-upgrading role that La0.8Sr0.2CoO3 plays in the thermoelectric properties of Bi Cu Se O（BCSO） has been studied. LSCO was introduced into BCSO, increasing the electrical conductivity from 3.3 to 52.3 S cm^-1 at 303 K, from 35.8 to 97.3 S cm^-1 at 873 K; respectively. The Seebeck coefficient of all composites still holds around or more than 200 μV/K. Based on the enhanced electrical conductivity and high Seebeck coefficient, the power factor is enhanced by approximately 35%, with the best sample reaching a maximum value of 476.7 μ Wm^-1 K^-2 at 873 K. The lattice thermal conductivity of the nanocomposites is reduced as LSCO content increases from 15 vol% to 30 vol% due to the phonon scattering by nanoparticles and grain boundaries, resulting in a significant reduction in total thermal conductivity. In short, the enhanced thermoelectric figure of merit of 0.67 at 873 K for the sample containing 20 vol% LSCO as compared to 0.53 for the pure sample; announces the promising effect of LSCO on improving thermoelectric properties of Bi Cu Se O.
LIU YaoChunLAN JinLeZHANG BoPingLIN YuanHuaNAN CeWen
