2D/2D W-MoSe2@Ti3C2 MXene heterostructure harnesses high-rate lithium–oxygen batteries: momentous roles of high-valence metal sites and interfacial bridge-oxygen bonding

Abstract

The synergistic integration of high-valence metal sites and interfacial bridge-oxygen bonding plays a pivotal role in the construction of valid bifunctional electrocatalysts for accelerating oxygen electrode redox kinetics and promoting the practical implementation of lithium–oxygen batteries. Herein, high-valence tungsten dopants induced the formation of 2H-MoSe₂, which was successfully anchored on the layered Ti₃C₂ MXene matrix (W-MoSe₂@MXene) with an interfacial bridge-oxygen bonding structure, affording a porous and vertical staggered nanosheet array network architecture. Consequently, the Li–O₂ battery assembled with the as-prepared W-MoSe₂@MXene cathode delivers high discharge specific capacity (12442.6 mA h g⁻¹) and favorable cycling lifespan (over 194 cycles) at 1 A g⁻¹. Notably, stable operation is also maintained over 61 cycles at an ultra-high current density of 5 A g⁻¹. Experimental analysis in combination with density functional theory (DFT) calculation reveals that the synergistic interaction between high-valence W dopants and bridge-oxygen bonds facilitates spatial charge redistribution and accelerates charge transfer, thereby lowering the theoretical discharge–charge overpotential and enhancing electrode reaction kinetics. This work offers a feasible design paradigm for the construction of MXene-based oxygen electrode catalysts toward high-rate Li–O₂ batteries.