Development of Skutterudite-Type Thermoelectric Materials La_xCo₄Sb₁₂ Using High-Pressure Synthesis Method

The extensive consumption of fossil fuels and other energy resources worldwide necessitates the exploration of alternative energy sources. Thermoelectric power generation is one of the most prominent technologies to convert heat energy into electrical energy. Numerous researchers have devoted significant efforts to enhancing the efficiency of thermoelectric technology through the synthesis of nanomaterials using various methodologies. Among these methods, high-pressure synthesis emerges as one of the most efficient techniques for synthesizing thermoelectric materials. In this study, we fabricated skutterudite-type thermoelectric materials of LaxCo4Sb12 by using a high-pressure synthesis method with a high filling rate, where the actual filling fraction can increase up to x = 0.28, exceeding the theoretical filling limit at ambient pressure. As a result, LaxCo4Sb12 shows a significantly lower lattice thermal conductivity value of 1.3 W/mK which is much lower value than for CoSb3. The results clearly demonstrate that the high-pressure synthesis method is a promising tool for enhancing the performance of thermoelectric materials.