Taming the Activity‐Stability Trade‐Off in Lithium‐Oxygen Batteries via Lattice Strain‐Mediated <i>d</i> ‐Band Center Modulation in High‐Entropy Alloys

ABSTRACT High‐entropy alloys (HEAs) show great promise as cathode materials for lithium‐oxygen batteries due to their unique catalytic properties. This study designed and synthesized a series of ruthenium‐based alloy nanocatalysts with varying entropy levels (Ru@NC, CoRu@NC, CoNiCuRu@NC, FeCoNiCuRu@NC) via a pyrolysis‐reduction method. Calculations reveal that Fe acts as a “structural‐electronic synergistic modulation hub”. Its introduction enhances lattice distortion via the high‐entropy effect, constructing a local asymmetric stress field at the atomic scale and optimizing the local microenvironment of metal sites. Meanwhile, electronegativity differences between Fe and other multi‐components synergistically drive electron redistribution. These effects shift the d ‐band center of Ru sites upward, enhancing adsorption of key oxygen intermediates, optimizing the reaction pathway, and improving bifunctional catalytic kinetics. Furthermore, the pronounced lattice distortion establishes an effective “atomic diffusion barrier”, inhibiting active metal dissolution and migration and enhancing structural stability. The lithium‐oxygen battery using this high‐entropy catalyst achieves outstanding performance, including reduced charge/discharge overpotential and enhanced long‐term cycling stability. From the perspective of “electron redistribution triggered by lattice strain and elemental synergy”, this study provides insights into the catalytic enhancement mechanism of HEAs, offering a new design strategy to address the “activity‐stability trade‐off” in electrocatalysis.