Unveiling Electrolyte Effects on the Oxygen Reduction at Co–N–C Single-Atom Catalysts in Nonaqueous Lithium–Oxygen Batteries by Ab Initio Molecular Dynamics

Nonaqueous lithium–oxygen batteries (LOBs) hold immense promise due to their ultrahigh theoretical energy density, yet the role of electrolytes in regulating reaction kinetics during the oxygen reduction reaction (ORR) remains fundamentally unclear. Here, we systematically explore ORR pathways at the interface between Co–N–C single-atom catalysts (SACs) and electrolytes via ab initio molecular dynamics (AIMD). In bulk electrolytes, simulations reveal Li⁺-solvent bonding strength follows donor number (DN) order, which may result in a difference in the free energy of interfacial reaction. High-DN solvents elevate Li⁺ insertion barrier due to strong Li⁺-solvent binding, while facilitating *LiO₂ desorption at the interface. However, the desorption of *LiO₂ into the electrolytes is found to be thermodynamically unfavorable, thereby driving the reaction toward surface-mediated growth. Low-DN electrolytes paired with high-adsorption catalysts enforce surface growth, while high-DN systems with weak-adsorption catalysts favor solution growth. Our work proposes a catalyst–electrolyte interfacial Li⁺ competition principle that governs discharge product formation pathways and offers optimization strategies for LOBs.