Localized Ru-induced interfacial electronic reconstruction enables highly reversible Li–CO₂ batteries

Li–CO₂ batteries are promising for integrating energy storage with CO₂ utilization, yet their practical application is limited by poor reversibility of discharge product formation/decomposition. Rational regulation of interfacial electronic environments is therefore crucial for improving reaction reversibility and enhancing electrochemical performance. Herein, a Co-based catalyst with localized Ru incorporation was constructed through a zeolitic imidazolate framework-67 (ZIF-67)-derived structural confinement strategy. Localized Ru incorporation effectively reconstructs the local electronic environment of neighboring Co sites and induces interfacial electronic modulation. The Li–CO₂ battery with the Ru₁₅Co₈₅ nanoparticles (Ru₁₅Co₈₅-NPs) cathode delivers a low voltage gap of 1.11 V, a high Coulombic efficiency of 99.7%, and stable cycling over 750 cycles (3100 h), significantly superior to those with Co-NPs and Ru₅₀Co₅₀-NPs counterparts. The optimized Ru₁₅Co₈₅ catalyst exhibits regulated interfacial reaction, enabling more efficient Li₂CO₃-related conversion and decomposition processes. Density functional theory calculations further reveal that moderate Ru incorporation lowers the free-energy barrier of the rate-determining Li₂CO₃ formation step and reduces the Li₂CO₃ dissociation barrier to 0.65 eV. This work provides an effective strategy for regulating interfacial electronic environments through moderate Ru incorporation and offers new insights into the design of highly reversible Li–CO₂ battery catalysts.