The Surface Electronic Structure Reconstruction of Co<sub>2.85</sub>Mn<sub>0.15</sub>O<sub>4</sub> with High Active Sites for High-Efficient Lithium–Oxygen Batteries
Zhencheng Xie, Zheng-Xuan Lu, Junkai Wang, Yuanduo Qu, Lianfeng Duan
Abstract
Spinel structure Co 3 O 4 has been used as cathode catalysts for lithium–oxygen batteries, because of the structural stability, abundant oxygen vacancies, and adjustable Co 3+ /Co 2+ ratio. Most reports focused on adjusting the anion–cation ratio and coordination state in Co 3 O 4 to enhance its ORR and OER activities. Based on this, we interfered with the distribution of Co 2+ /Co 3+ by introducing Mn 3+ . Li 2 O 2 was detected as a discharge product by in situ characterization methods, but the charging voltage was only 3.25 V. During charge and discharge, Mn-containing Co 3 O 4 has a higher reversible shift of Co 3+ /Co 2+, 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.