Recent advances in Ti₃C₂T_x MXene-based anode materials for lithium/sodium-ion batteries

Two-dimensional transition metal carbides and/or nitrides (MXenes) have garnered eye-catching attention in the field of energy storage because of their high specific surface area, easily adjustable structure, and excellent electron transfer capability. Among them, Ti₃C₂T_x (T=O, OH, and F), the most prototypical MXene, renowned for its excellent electroconductivity and low ion diffusion barrier, outperforms other carbides in enhancing battery rate capabilities and accommodating various large metal ions. Consequently, it has been regarded as a strong competitor to replace graphite with next-generation anodes for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). However, poor stability and severe self-stacking of Ti₃C₂T_x nanosheets result in low specific capacity and capacity recession during prolonged cycling. To address these issues, intensive research efforts have been devoted to surface modification and structural engineering strategies to optimize Ti₃C₂T_x-based materials. This review presents a comprehensive summary of recent advancements in Ti₃C₂T_x-based materials regarding surface and structure engineering, highlights their electrochemical performance in LIBs and SIBs as anodes, and outlines the remaining challenges and future perspectives for further substantial improvement and practical implementation.