Electronic structure modulation of Ru/W20O58 catalyst via interfacial Ru–O–W bridging bond for high-performance Li–O2 batteries

Abstract

The development of advanced catalysts with high activity is crucial to addressing the issues of sluggish reaction kinetics at the cathode of Li–O2 batteries. Herein, the authors propose a facile strategy to synthesize Ru nanoparticles anchored on non-stoichiometric tungsten oxide nanosheets (Ru/W20O58) hybrids. The non-stoichiometric lattice structure of W20O58 provides abundant surface nucleation sites, and the defects-induced restriction effect inhibits the agglomeration of Ru nanoparticles. The interfacial covalent coupling between Ru and W20O58 facilitates charge transfer at the interface via Ru–O–W bridging bond and optimizes the electronic structure of catalysts surface. As the obtained Ru/W20O58 employed as cathode catalysts, Li–O2 batteries exhibit high specific discharge capacity of 6346.4 mAh g−1, improved rate performance and a cycling life of 260 cycles. The density functional theory calculation demonstrate that the interfacial coupling enhances the adsorption energy of intermediates on the surface and regulates the discharge reaction pathway, leading to the restraint of O2– nucleophilic attack and the formation of amorphous and decomposable discharge products. This work provides an insight on the correlation between electrochemical activity and interfacial coupling, shedding lights on a promising cathode catalyst for advanced Li–O2 batteries.