Ti₃C₂T_x MXene based materials in lithium-air battery cathode: a progress review

Lithium-air battery (LAB) has a theoretical energy density of 3500 W·h·kg⁻¹, therefore is considered a potential next-generation energy storage system．The discharge product of the cathode in non-water LAB is solid-state Li₂O₂, which is insulative and leads to slow reaction kinetics, resulting in high reaction overpotential, poor rate performance, limited cycling stability and low energy efficiency．Catalysts can improve the kinetically slow rates of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER)．The development of stable catalysts with high catalytic activity is a key to improve LAB performance．Ti₃C₂T_x MXene is a two-dimensional layered titanium carbon/nitride nanomaterial discovered in 2011 with dual function catalytic activity in the ORR and OER, which has received widespread attention in recent years as typical high-efficiency catalyst with promising application in LAB．In this paper we discuss the reaction mechanism of LAB, summarize research progress of Ti₃C₂T_x MXene based materials in LAB in recent years．We discuss the reaction mechanism and performance improvement strategy of Ti₃C₂T_x MXene based cathode catalyst materials in LAB, and finally provide some perspectives for future developments in this direction．