Electron Localization in Rationally Designed Pt₁Pd Single-Atom Alloy Catalyst Enables High-Performance Li-O₂ Batteries

Li-O₂ batteries (LOBs) are considered as one of the most promising energy storage devices due to their ultrahigh theoretical energy density, yet they face the critical issues of sluggish cathode redox kinetics during the discharge and charge processes. Here we report a direct synthetic strategy to fabricate a single-atom alloy catalyst in which single-atom Pt is precisely dispersed in ultrathin Pd hexagonal nanoplates (Pt₁Pd). The LOB with the Pt₁Pd cathode demonstrates an ultralow overpotential of 0.69 V at 0.5 A g^-1 and negligible activity loss over 600 h. Density functional theory calculations show that Pt₁Pd can promote the activation of the O₂/Li₂O₂ redox couple due to the electron localization caused by the single Pt atom, thereby lowering the energy barriers for the oxygen reduction and oxygen evolution reactions. Our strategy for designing single-atom alloy cathodic catalysts can address the sluggish oxygen redox kinetics in LOBs and other energy storage/conversion devices.