MXenes and Their Derivatives for Advanced Solid‐State Energy Storage Devices

Abstract Solid‐state energy storage devices (SSESDs) are believed to significantly improve safety, long‐term electrochemical/thermal stability, and energy/power density as well as reduce packaging demands, showing the huge application potential in large‐scale energy storage. Nevertheless, some key issues like low ionic conductivities, poor interface contact, and dendrites growth limit the practical application of SSESDs. In recent years, MXenes for SSESDs have received reassuring advances on account of unique parameters. Nevertheless, overall reviews about the subject are seldom. In this review, current advances of MXenes and their derivatives in solid‐state Li–metal, Li‐ion, Li–I/S, Na‐ion, Zn–air, Zn–metal batteries, and supercapacitors in cathode/anode optimization, interface medication, and electrolyte fillers, etc., are comprehensively reviewed. First of all, essential principles of MXenes are shown, such as precursors, etching/delamination strategies, as well as superior properties for energy storage systems. Meanwhile, the classification and evaluation parameters of solid‐state electrolytes are summarized. Subsequently, the application, modification mechanism, and design strategy of MXenes for boosting electrochemical behaviors of SSESDs are systematically reviewed and discussed. At last, perspectives and challenges about the future construction strategies of MXenes for SSESDs are recommended. This review shall assist scientists design and build advanced SSESDs with superior energy density along with safety.