High-Conductive Multilayer TiO_X-Ti₃C₂T_X Electrocatalyst for Longevous Metal-Oxygen Battery under a High Rate

Abstract

Metal-oxygen batteries (especially Li-O2 battery) with ultrahigh theoretical energy density are of great promise for long-range vehicle electrification. However, the limited enduring stability and low-rate property further restricted the large-scale commercial application of metal-oxygen batteries. We firstly report the fabrication of a TiOX@Ti3C2TX with multilayer structure and its utilization as cathode for Li-O2 batteries. The TiOX protective layer was fabricated in situ to directly optimize surface properties of Ti3C2TX, as well as to strengthen surface active functional groups. The initial discharge capacity of as-prepared TiOX@Ti3C2TX cathode reaches 7100 mAh g−1 at 2500 mA g−1, as well as delivers impressive cycling stability (>100 cycles) at 2500 mA g−1. Experimental analysis reveals that the in situ TiOX protective layer enhanced active functional-groups and the improved complete decomposition of discharge products Li2O2 are three critical factors for promoting the electrochemical performance of LOBs. This work exhibits a new insight into the design of MXene electrocatalysts for metal-oxygen batteries.

Keywords

• Ti₃C₂T_X
• TiO_X protective layer
• active functional-groups
• bifunctional electrocatalysts
• Li-O₂ battery