Manipulating Electron\nDelocalization of Metal Sites\nvia a High-Entropy Strategy for Accelerating Oxygen Electrode Reactions\nin Lithium–Oxygen Batteries

High-entropy perovskite oxides, in which the B-type metal\nsite\nof perovskite oxides (ABO<sub>3</sub>) is occupied by over five kinds\nof transition metal ions, show promising applications in energy storage\nand conversion fields. Herein, high-entropy perovskite oxides (LaSr(5TM)O<sub>3</sub>) composed of Cr, Mn, Fe, Co, and Ni at the B-type metal site\nare prepared as oxygen electrocatalysts for Li–O<sub>2</sub> batteries. The presence of compressive strain in LaSr(5TM)O<sub>3</sub> effectively regulates the 3d orbit occupancy of the active\nCo site (Co<sup>2+</sup> → Co<sup>3+</sup>) and lifts the energy\nlevel of the Co d-band center, thus leading to enhanced adsorption\ntoward the LiO<sub>2</sub> intermediate on Co sites. Furthermore,\nthe high electron-drawing capability of Cr sites ensures sufficient\nelectron exchange and further strengthens the adsorption of LiO<sub>2</sub>. As expected, the Li–O<sub>2</sub> battery with a\nLaSr(5TM)O<sub>3</sub> electrode delivers a low overpotential (0.79\nV) and superior cyclability (226 cycles). This study provides a meaningful\nstrain strategy to improve the electrocatalytic activity of multicomponent\noxides via fabricating high-entropy materials.