Recent progress on the cathode-electrolyte interface for Li thermal battery

Lithium thermal batteries (LTB) have gained significant attention as a class of power source devices because of their high power, long storage life, and tolerance to harsh environments. Miscellaneous advanced cathode materials, mainly including transition metal sulfides, transition metal oxides, transition metal chloride, transition metal fluoride, and so on, have been adopted to enhance the energy density of LTB. However, some inherent problems of cathode materials, such as low conductivity and incompatibility with electrolytes, can result in an unstable cathode-electrolyte interface, which can rapidly deteriorate electrochemical performance and even cause safety issues for LTB, especially at high temperatures. Herein, in this review, advanced strategies for cathode-electrolyte interface to ameliorate LTB performance, including the modification of cathode material, architectural design of cathode, and electrolyte engineering, are systematically discussed and summarized. Notably, the mechanism of interfacial reactions that occur in the cathode materials at elevated temperatures is also deeply elaborated. Finally, some challenges and future directions of LTB are outlined. This review will light on some insights into a comprehensive understanding of LTB and give guidance for intensive research.