THERMOELECTRIC PERFORMANCE OF CALCIUM AND CALCIUM-CERIUM FILLED N-TYPE SKUTTERUDITES

摘要

A method is disclosed for inserting elemental calcium and cerium as low cost fillers in n-type Co₄Sb₁₂ type skutterudite compositions for use in thermoelectric applications. It is found that the inclusion of calcium oxide (and to a lesser extent, cerium oxide) in the Co₄Sb₁₂ skutterudite compositions, as the filled-crystalline compositions are being made, markedly reduces the thermoelectric properties of the intended calcium-filled crystalline product. A synthesis process, including careful control of melt spinning of a melt of calcium-containing, or calcium and cerium-containing, cobalt and antimony composition, leads to the formation of substantially oxide-free, calcium filled-precursor particles that can be compacted, sintered, and transformed into calcium-filled n-type skutterudite billets that have excellent thermoelectric properties.