MXene-based electrode materials for supercapacitors: Synthesis, properties, and optimization strategies

MXene materials, as a class of advanced functional nanomaterials, exhibit a wide range of applications including energy storage and conversion, sensing, electromagnetic shielding, and biomedicine. Owing to their metallic conductivity, tunable surface functional groups, unique two-dimensional layered structure, and pseudocapacitive charge storage mechanism, MXene materials have garnered significant attention in the field of supercapacitors. In this paper, we provide a comprehensive overview of MXene synthesis methods and characteristics. Subsequently, we delve into a discussion of the electrochemical performance of MXene materials, elucidate their charge storage mechanisms, and explore strategies for enhancing their performance. We also introduce the development of composite electrode materials by incorporating MXene with carbon materials, metal oxides, and conductive polymers, showcasing their outstanding composite performance. As microscale MXene-based supercapacitors rapidly advance, we also address these developments in our discourse. This review serves as a valuable reference for further exploration and application of MXene materials in the energy storage field. Not only does it offer a comprehensive summary of the latest progress in MXene-based electrode materials for supercapacitors, but it also anticipates potential future research directions. The aim is to drive the utilization of MXene materials in the realm of supercapacitors, providing guidance towards achieving high volumetric capacitance, excellent cycling stability, and rate capability in supercapacitor development.