Effect of fullerene addition on thermoelectric properties ofn-type skutterudite compound

Abstract

Thermoelectric power generation is a promising method for harnessing waste thermal energy, especially in the temperature range between 500 and 800 K. It is necessary to improve the performance of thermoelectric materials for the realization of the power generation. Dispersion of nanoparticles such as fullerenes is expected to induce phonon scattering that decreases thermal conductivity of materials, and application to thermoelectric materials may lead to improved properties. In the present study, then-type Co0.92Ni0.08Sb2.96Te0.04thermoelectric compound was synthesized, and the thermoelectric properties were evaluated. Furthermore, the fullerene particles were sufficiently mixed with the thermoelectric compound powder by the mechanical grinding method, and influences of the fullerene additions to the compound were investigated. The dispersion of fullerene particles in then-type Co0.92Ni0.08Sb2.96Te0.04compound was conducted through the planetary ball milling method to disentangle agglomerates of the fullerene and to disperse the particles in the thermoelectric compound matrix. The thermal conductivity decreased with an increase in fullerene content, and the maximum in dimensionless figure of meritZTwas 0.62 at 800 K for 1 mass% fullerene addition. This was 28% higher than that of fullerene-free sample.