MXene-based zinc-ion batteries: synthesis, applications, and strategies for performance optimization

Abstract

Aqueous zinc-ion batteries (ZIBs) have garnered significant research attention due to their distinct advantages, such as low cost, safety, and environmental compatibility. However, the development of ZIBs is significantly hindered by their limited specific capacity, energy density, and power density. MXenes have emerged as a prominent family of two-dimensional transition metal carbides or carbonitrides, characterized by a series of unique physicochemical properties. Recently, MXenes have been widely applied in the development of ZIBs (e.g., cathodes, anodes and electrolytes), leading to remarkable performance gains including high specific capacity (508 mA h g⁻¹), ultralong cycling (25 000 cycles), and dendrite suppression (2100 h stability). This paper aims to provide a concise overview of recent advancements in the application of MXenes in ZIBs. It summarizes MXene synthesis routes including HF etching and molten salt methods with their chemical characteristics. The applications of MXenes in cathodes, anodes, and electrolytes/diaphragms of ZIBs are then introduced, highlighting their immense potential in developing high-performance ZIBs. For example, in cathodes, MXenes enhance conductivity and structural integrity; in anodes, they enable dendrite-free plating; in electrolytes, they regulate ion transport. The review also discusses strategies for optimizing the performance of MXene-based ZIBs, including intercalation adjustment, surface modification, heteroatom doping, and interlayer spacing expansion. Finally, this review addresses the current challenges and future prospects for MXene-based ZIBs, paving the way for further research and development in this promising field.