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.image

Extremely Low Lattice Thermal Conductivity and Significantly Enhanced Near-Room-Temperature Thermoelectric Performance in α-Cu2Se through the Incorporation of Porous Carbon

“…Superionic cuprous selenide is a well-known high performance TE material due to its special characteristic of “phonon-liquid electron-crystal” at high temperatures with a cubic structure (β-Cu 2 Se). − However, the low-temperature monoclinic structure (α-Cu 2 Se) also has a low lattice thermal conductivity and a high electrical transport performance due to its internal nonharmonic vibration, which also has great application potential in the field of near-room-temperature thermoelectric materials. , Recently, with the rapid development of thermoelectric devices such as temperature sensors, wearable electronic devices, and Peltier cooling devices, near-room-temperature thermoelectric materials with high performance have attracted the attention of researchers. − Bi 2 Te 3 has been a popular near-room-temperature thermoelectric material for the past few decades due to its excellent thermoelectric properties. , However, although Bi 2 Te 3 has a high ZT value, Bi and Te elements are not abundant in nature, which greatly increases the production cost . Therefore, α-Cu 2 Se has attracted wide attention as an excellent near-room-temperature thermoelectric material that can hopefully replace Bi 2 Te 3 due to its low price and nontoxic and pollution-free characteristics. ,,, …”