Recent advances, challenges, and perspective of copper‐based liquid‐like thermoelectric chalcogenides: A review

Abstract As a group of emerging liquid‐like thermoelectric materials for waste heat recovery into useful energy, di‐chalcogenides Cu2(S, Se, Te) have been considered as superionic thermoelectric materials. Due to their highly disordered degree of Cu‐ion in the crystal lattice, Cu2(S, Se, Te) compounds can exhibit ultralow thermal conductivity, and in the meantime, their rigid sublattice can decently maintain the electrical performance, making them distinct from other state‐of‐the‐art thermoelectric materials. This review summarizes the well‐designed strategies to realize the impressive performance in thermoelectric materials and their modules by linking the adopted approaches such as defect engineering, interfaces, nano‐porous inclusions, thin films, dislocations, nano‐inclusions, and polycrystalline bulks etc., with the moderate design of the device. Some recent reports are selected to outline the fundamentals, underlined challenges, outlooks, and future development of Cu2(S, Se, Te) liquid‐like thermoelectric materials. We expect that this review covers the needs of future researchers in choosing some potential materials to explore thermoelectricity and other efficient energy conversion technologies