Partial‐Oxidation Enabling Homologous Ru/RuO<sub>2</sub> Heterostructures With Proper d‐Dand Center as Efficient and Durable Cathode Catalysts for Ultralong Cycle Life in Li–O<sub>2</sub> Batteries
Chaoyang Sun, Fenglong Xiao, Meiyan Li, Deliang Cui, Qilong Wang, Feng Dang, Haohai Yu, Gang Lian
Abstract
Abstract The sluggish cycle kinetics is one of the major obstacles to the commercial application of Li–O 2 batteries (LOBs), despite their large theoretical energy density. Efficient and long‐term durable cathode catalysts are urgently desired to strengthen their cycle stability and rate performance. Density functional theory calculations reveal that Ru/RuO 2 Mott–Schottky heterostructures can manipulate the adsorption capacities of intermediates by modulating the d‐band center and redistribute interfacial charges, enabling efficient redox kinetics, reducing overpotentials, and optimizing the growth pathway of discharge products. Herein, a wet impregnation approach followed by partial oxidization of Ru nanodots to construct homologous Ru/RuO 2 heterostructures as advanced cathode catalysts for boosting the electrochemical activities of LOBs is employed. They exhibit superior electrochemical performance, including high discharge specific capacity (17 120 mAh g −1 at 200 mA g −1 ), small overpotential (0.96 V), and ultralong cycle lifetime of 1209 cycles (>2400 h) at 500 mA g −1 . Over 1260‐h stable cycle in air atmosphere at 500 mA g −1 demonstrates the potential application prospects of the Ru/RuO 2 heterostructures in Li‐air batteries. Multiple ex/in situ measurements and theoretical calculation are conducted to investigate the optimizing mechanism of electrochemical performances.