Breaking Redox Barriers in Lithium-Oxygen Batteries via Multiscale Architecture of Pyridinic Nitrogen-Doped Carbon-Encapsulated Cobalt Catalysts

Lithium-oxygen batteries (LOBs) are limited by sluggish oxygen redox kinetics and cathode instability. Herein, we report a cobalt particle catalyst encapsulated in nitrogen-doped carbon (Co@NC) with a three-dimensional hierarchical architecture, synthesized via a chitosan-derived hierarchical porous carbon framework. This innovative design integrates uniformly dispersed ultra-thin carbon shells (11.7 nm), pyridinic nitrogen doping, and Co particles (1.41 μm) stabilized through carbon-support electronic coupling. The hierarchical porosity facilitates rapid O₂/Li⁺ mass transport, while pyridinic N sites act as dual-function electrocatalytic centers for Li₂O₂ nucleation and charge transfer kinetics. Co@NC achieves 11,213 mAh g⁻¹ at 200 mA g⁻¹ (126.5% higher than nitrogen-doped carbon) and maintains 1.54 V overpotential (500 mAh g⁻¹). These metrics outperform benchmark catalysts, addressing kinetic and stability challenges in LOBs. The study advances electrocatalyst design by integrating structural optimization, heteroatom doping, and electronic coupling strategies for high-performance metal–air batteries.