The Surface Electronic Structure Reconstruction of Co2.85Mn0.15O4 with High Active Sites for High-Efficient Lithium-Oxygen Batteries

Spinel structure Co3O4 has been used as cathode catalysts for lithium-oxygen batteries, because of the structural stability, abundant oxygen vacancies, and adjustable Co3+/Co2+ ratio. Most reports focused on adjusting the anion-cation ratio and coordination state in Co3O4 to enhance its ORR and OER activities. Based on this, we interfered with the distribution of Co2+/Co3+ by introducing Mn3+. Li2O2 was detected as a discharge product by in situ characterization methods, but the charging voltage was only 3.25 V. During charge and discharge, Mncontaining Co3O4 has a higher reversible shift of Co3+/Co2+, and this surface electron reconstitution effect leads to an extremely low overpotential (0.29 V). The surface electronic structure modified strategy and reversibility verification method could be a positive significance in the application of lithium-oxygen batteries, especially for reducing the use of noble metal catalysts.