Nanocomposite thermoelectric materials for improving the performance of solid oxide fuel cells

The article considers the possibilities of using thermoelectric materials to improve the operation of solid oxide fuel cells (SOFC). The main attention is paid to the development and study of nanostructured alloys based on superionic copper chalcogenides, which have low thermal conductivity and high thermoelectric figure of merit. The study found that the nanostructured Li0.11Cu1.89S alloy has a high thermoelectric figure of merit and reaches ZT = 1.76 at a temperature of 672 K, which indicates its high efficiency in converting heat into electricity and is promising for use in SOFC. Experimental studies of the temperature dependence of thermal conductivity showed that the Li0.11Cu1.89S alloy has a maximum value of 0.71 W m⁻¹ K⁻¹ at room temperature, with a subsequent decrease to 0.22 W m⁻¹ K⁻¹ at 373 K, which confirms the presence of pronounced phonon scattering and helps to maintain the thermal gradient in the material. For the cathode material SrcFeO0.6CuO0.3Mo0.1O3, a significant decrease in thermal conductivity from 6.8 W m⁻¹ K⁻¹ to 2 W m⁻¹ K⁻¹ is observed, indicating a weakening of phonon heat transfer, which is due to the doping of copper and molybdenum atoms into the perovskite lattice of Fe-containing Sr-oxide and makes the material a promising candidate for high-temperature operation in SOFC. The results of the work confirm the potential of using thermoelectric materials to improve the efficiency of SOFCs and optimize their design, and also highlight key areas for further research in this area. Keywords: thermoelectric materials; copper sulfide; thermal conductivity; Seebeck coefficient; superionic conductors, solid oxide fuel cells.