Promising and Eco‐Friendly Cu₂X‐Based Thermoelectric Materials: Progress and Applications

Due to the nature of their liquid-like behavior and high dimensionless figure of merit, Cu₂ X (X = Te, Se, and S)-based thermoelectric materials have attracted extensive attention. The superionicity and Cu disorder at the high temperature can dramatically affect the electronic structure of Cu₂ X and in turn result in temperature-dependent carrier-transport properties. Here, the effective strategies in enhancing the thermoelectric performance of Cu₂ X-based thermoelectric materials are summarized, in which the proper optimization of carrier concentration and minimization of the lattice thermal conductivity are the main focus. Then, the stabilities, mechanical properties, and module assembly of Cu₂ X-based thermoelectric materials are investigated. Finally, the future directions for further improving the energy conversion efficiency of Cu₂ X-based thermoelectric materials are highlighted.