The study investigates the catalytic role of in-situ formed C-N species in enhancing the Li₂CO₃ decomposition kinetics in Li-Co₂ batteries. The sluggish kinetics of CO₂ reduction/evolution reactions lead to the accumulation of Li₂CO₃ residuals, which can cause catalyst deactivation and hinder long-term cycling stability. The research systematically regulates the compositions of solid-electrolyte interphase (SEI) layers by tuning electrolyte solvation structures, anion coordination, and binding free energy between Li ions and anions. The cells with increasing content of C-N species in the SEI layers exhibit improved cycling performance. The enhancement is attributed to the catalytic effect of C-N species, which accelerate the Li₂CO₃ formation/decomposition kinetics. Theoretical analysis reveals that C-N species provide strong adsorption sites and promote charge transfer during discharge and charge, forming a bidirectional fast-reacting bridge for CO₂ reduction/evolution reactions. This finding enables the design of a C-N rich SEI layer using dual-salt electrolytes, significantly improving the cycle life of Li-Co₂ batteries to twice that of traditional electrolytes. The study provides insights into the interfacial design by tuning catalytic properties to enhance CO₂ reduction/evolution reactions.The study investigates the catalytic role of in-situ formed C-N species in enhancing the Li₂CO₃ decomposition kinetics in Li-Co₂ batteries. The sluggish kinetics of CO₂ reduction/evolution reactions lead to the accumulation of Li₂CO₃ residuals, which can cause catalyst deactivation and hinder long-term cycling stability. The research systematically regulates the compositions of solid-electrolyte interphase (SEI) layers by tuning electrolyte solvation structures, anion coordination, and binding free energy between Li ions and anions. The cells with increasing content of C-N species in the SEI layers exhibit improved cycling performance. The enhancement is attributed to the catalytic effect of C-N species, which accelerate the Li₂CO₃ formation/decomposition kinetics. Theoretical analysis reveals that C-N species provide strong adsorption sites and promote charge transfer during discharge and charge, forming a bidirectional fast-reacting bridge for CO₂ reduction/evolution reactions. This finding enables the design of a C-N rich SEI layer using dual-salt electrolytes, significantly improving the cycle life of Li-Co₂ batteries to twice that of traditional electrolytes. The study provides insights into the interfacial design by tuning catalytic properties to enhance CO₂ reduction/evolution reactions.