Solid-state redox mediator engineering of the Ag cluster/CoMoO4 heterostructure for accelerated LiOx conversion kinetics

Abstract

Facing growing energy demands, lithium–oxygen batteries (LOBs) offer a promising high-energy-density alternative but suffer from sluggish oxygen electrocatalysis at the cathode. This work innovatively demonstrates that rational modulation of the metal–support interaction (MSI) between Ag and vacancy-rich CoMoO₄ serves as an effective strategy for designing high-performance catalysts. By precisely controlling the Ag incorporation ratio, a series of Ag/CoMoO₄ electrocatalysts were successfully constructed, wherein the unique solid state redox mediator properties of Ag nanoclusters with the CoMoO₄ substrate were activated and superior electrocatalytic activity was achieved via accelerated LiO_x conversion kinetics. The optimized Ag/CoMoO₄-2 catalyst exhibited bifunctional activity for both the oxygen reduction and evolution reactions (ORR/OER) in LOBs, with a high discharge capacity of 13 886 mAh g⁻¹, reduced overpotentials of 100 mV, and an extended cycle life, double that of pristine CoMoO₄. These findings highlight the critical role of the Ag/CoMoO₄ heterostructure in modulating the electronic structure, promoting the adsorption of intermediates and enhancing the reaction kinetics, providing a viable strategy for developing high-performance LOBs.