Optimizing the endurance mechanisms of chalcogenide-based thermoelectric materials and devices

With superior thermoelectric transport properties, chalcogenide-based materials are considered to be promising candidates for energy conversion. As compared to the strategies enhancing thermoelectric performance, the related research works focusing on endurance mechanisms during long-term working, however, are insufficient and should be systematically evaluated for making broad applications. Specifically, systematic issues divided into mechanic, thermodynamic, and kinetic sections could play a predominated role in challenging different constituents per the intrinsic mechanisms, and the inferior stability of chalcogenides limits further developments in the next decades. In this review, typical material systems like Pb-, Cu-, and Bi-based chalcogenides as well as several emerging compounds like Ag-, Sn-, and oxygen-containing compounds would be referred and discussed extensively, focusing on the endurance ability. Subsequently, four kinds of mechanisms at different levels would be systematically summarized and investigated: first, considering the key roles on affecting mechanical stability and optimizing the compositions for forming proper bonding strength and microstructures for high density are required. Second, it is crucial to explore the interactions between the elemental vapor pressure and the service temperature in chalcogenides. Third, the uncertainties introduced by phase-transition phenomena cannot be ignored. In addition, nano-precipitates from low melting point components also put forward high requirements on the endurance. Furthermore, the coincided improvements could benefit the enhanced stability and output performance of applied devices. These unique advances combined with the corresponding strategies for long-term endurance demonstrate the potential of high-performance chalcogenides for large-scale power generation applications.