Ruthenium atoms anchored on oxygen-modified molybdenum disulfide with strong interfacial coupling as efficient and stable catalysts for lithium–oxygen batteries

Abstract

Rechargeable non-aqueous lithium-oxygen batteries (LOBs) have garnered increasing attention owing to their high theoretical energy density. However, their slow cathodic kinetics hinder efficient battery reactions. Nanoscale catalysts can effectively enhance electrocatalytic activity and atomic utilization efficiency. However, the agglomeration of nanoscale catalysts (such as cluster and single atoms) during continuous discharge/charge cycles leads to decreased electrochemical performance and poor cyclic stability. Herein, the ruthenium (Ru) atomic sites anchored on an O-doped molybdenum disulfide (O-MoS₂) catalyst (designated as Ru/O-MoS₂) was fabricated using a facile impregnation and calcination method. Strong Ru-O coupling between Ru atoms and the O-MoS₂ substrate optimizes the localized electronic structure, resulting in improved electrochemical performance and enhanced resistance to Ostwald ripening. When employed as a cathode catalyst for LOBs, Ru/O-MoS₂ catalyst exhibits a high reversible specific capacity (18700.5 (±59.8) mAh g⁻¹), good rate capability, and enhanced long-term stability (115 cycles, 1200 h). This study encourages facile and efficient strategies for the development of effective and stable electrocatalysts for use in LOBs.