Synthesis And Thermoelectric Properties Of Skutterudite Compounds With Ba Filled

The filled Skutterudite compounds attract aboard attention owing to their high mobilities and relatively large Seebeck coefficients in the middle temperature range of 600-800K. But their thermal conductivities are very high, so the problem how to decrease their lattice thermal conductivities and improve their ZT values becomes a research hotspot.In this research, n-type BayCo4Sb12 and p-type BayFeCo3Sb12 filled Skutterudite compounds were synthesized using a two-step solid-state reaction method. The upmost filled lattice constant is obtained 0.9085nm and 0.9105nm through calculation, which is increased with increasing Ba filling fraction. The influence of Ba filling fraction with the thermoelectric properties is discussed in detail. Different content carbon nanotubes are mixed into the Ba0.8FeCo3Sb12 compounds, and we also research the influence of the thermoelectric properties with the composing. Result shows that:For the n-type BayCo4Sb12 compounds, the electrical conductivity increased with increasing Ba filling fraction. The Seebeck coefficients are improved than that of CoSb3, especially in the middle temperature range. The lattice thermal conductivity decreased evidently, which is decreased with the Ba filling fraction. The maximum figure of merit ZTmax of Ba0.8SSb12 is 0.95 at 850K.For the p-type BayFeCo3Sb12 compounds, the electrical conductivity decreased with increasing Ba filling fraction. The Seebeck coefficients are improved than that of CoSb3 in the middle temperature range. The lattice thermal conductivity decreased evidently, which is decreased with the Ba filling fraction. The maximum figure of merit ZTmax of Ba0.8FeCo3Sb12 is 0.75 at 850K.For the p-type Ba0.8FeCo3Sb12 compounds with carbon nanotubes, the electrical conductivity decreased with increasing carbon nanotubes content, In the same temperature, the Seebeck coefficients are decreased with increasing carbon nanotubes content. The lattice thermal conductivity and thermal conductivity also decreased obviously. The minimum of the lattice thermal conductivity is content with 5% carbon nanotubes. The maximum figure of merit ZTmax of Ba0.8FeCo3Sb12+3% carbon nanotubes is 0.78 at 850K.