Dual-functional Mo/Mo₂N heterocatalyst engineering with optimized d-band center for efficient and stable Li-O₂ batteries

The practical deployment of lithium-oxygen (Li-O₂) batteries is hindered by the sluggish kinetics of the oxygen evolution reaction (OER), which lead to large charge overpotentials and poor cycling stability. Here, we designed a dual-functional heterostructured molybdenum nitride (Mo₂N) electrocatalyst via an isomorphic metal-anchoring strategy. This architecture synergistically enhances electrical conductivity, prevents nanoparticle agglomeration, and modulates the Mo d-band center through pronounced Mo-N covalency. As a result, the Mo/Mo₂N cathode delivers a low OER overpotential to 0.436 V at 100 mA g−1 and sustains 131 stable cycles at 500 mA g−1, markedly outperforming Mo and Mo/MoO₂ benchmarks. Combined experimental and theoretical analyses reveal that the heterostructure promotes a stepwise Li₂O₂ oxidation pathway via conductive Li_2−xO₂ intermediates, thereby significantly reducing the energy barrier and mitigating electrode passivation. This study establishes a general design principle for bifunctional electrocatalysts that unify electronic regulation with structural stabilization, offering a promising pathway toward practical high-energy Li-O₂ batteries.