Effect of multiwalled carbon nanotubes on the thermoelectric properties of p-type Ba0.3FeCo3Sb12 compounds

The p-type Ba-filled Ba-0.3 FeCo3Sb12 skutterudite compounds were synthesized using a two-step solid-state reaction method, and the Ba-0.3 FeCo3Sb12/multiwalle carbon nanotubes composites were prepared by spark plasma sintering (SPS). The structure of Ba-0.3 FeCo3Sb12/multiwalled carbon nanotube composites and effect of multiwalled carbon nanotubes on the thermoelectric properties of p-type Ba-0.3 FeCo3Sb12 compounds were investigated. The dispersed distribution of multiwalled carbon nanotubes in the Ba-0.3 FeCo3Sb12 compounds was observed by SEM. With increasing content of multiwalled carbon nanotubes, the electrical conductivity of the Ba-0.3 FeCo3Sb12 compounds decreased, Seebeck coefficient reduced slightly and the lattice thermal conductivity decreased significantly. The minimum of lattice thermal conductivity was obtained when the content of carbon nanotubes was 5%. When the content of carbon nanotubes was 3%, the maximal ZT value of 0.78 was obtained for Ba-0.3 FeCo3Sb12/multiwalled carbon nanotube composites at 850 K.