2D/2D W-MoSe2@Ti3C2 MXene Heterostructure Harness 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 was successfully anchored on the layered Ti3C2 MXene matrix (W-MoSe2@MXene) with interfacial bridge-oxygen bonding structure, affording the porous and vertically staggered nanosheets array networks architecture. Consequently, the Li-O2 battery assembled with the as-prepared W-MoSe2@MXene cathode delivers high discharge specific capacity (12442.6 mAh g‒1) and favorable cycling lifespan (over 194 cycles) at 1 A g‒1. Notably, stable operation is also maintained over 61 cycles under an ultra-high current density of 5 A g‒1. Experimental analysis in combination with density functional theory (DFT) calculation reveal that the synergistic interaction between high-valence W dopants and bridge-oxygen bonds facilitate spatial charge redistribution and accelerate charge transfer, thereby lowing 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.