Toward high performance all-solid-state lithium or sodium metal batteries: Potential application on Li/Na-rich antiperovskites (LiRAPs/NaRAPs) electrolyte for energy storage

All-solid-state lithium or sodium metal batteries with enhanced safety and energy density are widely anticipated to be utilized in the next-generation energy storage systems. The primary challenges involve two aspects: one is to obtain high performance solid-state electrolytes (SSEs) with appropriate mechanical strength and high ionic conductivity, and the other is to establish a stable interface between the SSEs and the electrode. The newly emerging Li/Na-rich antiperovskites (LiRAPs/NaRAPs) electrolytes exhibit inherent stability towards alkali metal anodes, and their exceptional ionic conductivity, wide electrochemical window, low cost, structural diversity, and the ability to be processed at a lower melting point (<300 degrees C) render them as promising candidates for all-solid-state battery applications. The research on antiperovskite for all-solid-state batteries (ASSBs) is in its infancy, so it is necessary to summarize the existing literature and stay updated on the continuously evolving strategies in this field to stimulate interest. This review provides a comprehensive overview for the structural properties, synthetic technique, advanced characterization and ionic transfer mechanisms of antiperovskite electrolytes. Finally, the effective strategies to improve ionic conductivity of LiRAPs/NaRAPs and alleviate the unstable electrode/electrolyte interface effect are discussed in detail, and the feasibility of antiperovskite as an ionic conductive additive is reasonably demonstrated, so as to enable a foundation for the future development and application of antiperovskite electrolyte-based batteries. With increased research fervor, antiperovskite is poised to emerge as a prominent contender in the realm of energy storage materials.