The roles of MXenes in developing advanced lithium metal anodes

Lithium (Li) metal has emerged as the most promising anode for rechargeable Li batteries owing to its high theoretical specific capacities, low negative electrochemical potential, and superior electrical conductivity. Replacing the conventional graphite anodes with Li metal anodes (LMAs) provides great potential to exceed the theoretical limitations of current commercial Li-ion batteries, leading to next-generation high-energy–density rechargeable Li metal batteries (LMBs). However, further development of LMAs is hindered by several inherent issues, such as dangerous dendrite growth, infinite volume change, low Coulombic efficiency, and interfacial side reactions. MXenes, a family of two-dimensional (2D) transition metal carbides and/or nitrides, have recently attracted much attention to address these issues due to their 2D structure, lithiophilic surface terminations, excellent electrical and ionic conductivity, and superior mechanical properties. Herein, an overview of recent advances in the roles of MXenes for stabilizing LMAs is presented. In particular, strategies of utilizing MXenes as the Li hosts, artificial protection layers, electrolyte additives, and for separator modifications to develop stable and dendrite-free LMAs are discussed. Moreover, a perspective on the current challenges and potential outlooks on MXenes for advanced LMAs is provided.