The role of catalysts in aprotic Li−O 2 batteries remains unclear. To identify the exact catalytic nature of oxide catalysts, a precisely surface-engineered model catalyst, perovskite (LaMnO 3 ), was investigated for oxygen reduction reaction/ oxygen evolution reaction (ORR/OER) in both aqueous and aprotic solutions. By using integrated theoretical and experimental approaches, we explicitly show that H + -ORR/OER catalytic activity on transition-metal sites fails to completely describe the electrochemical performance of LaMnO 3 catalysts in aprotic Li−O 2 batteries, whereas the collective redox of the lattice oxygen and transition metal on the catalyst surface during initial Li 2 O 2 formation determines their discharge capacity and charge overpotential. This work applies oxide catalyst design to tailor both the surface lattice oxygen and the transition-metal arrangement for an aprotic Li−O 2 battery. The optimized model catalyst shows good performance for Li−O 2 batteries under both oxygen and ambient air (real air) conditions.

The CNT@Ni@Ni–Co silicate core–shell composites prevent the formation of side-products via structural synergistic effects, thereby enhancing its electrochemical performances for Li–O2 batteries.

A defect engineering of inorganic solids garners great deal of research activities because of its high efficacy to optimize diverse energy-related functionalities of nanostructured materials. In this study, a novel in situ defect engineering route to maximize electrocatalytic redox activity of inorganic nanosheet is developed by using holey nanostructured substrate with strong interfacial electronic coupling. Density functional theory calculations and in situ spectroscopic analyses confirm that efficient interfacial charge transfer takes place between holey TiN and Ni−Fe-layered double hydroxide (LDH), leading to the feedback formation of nitrogen vacancies and a maximization of cation redox activity. The holey TiN−LDH nanohybrid is found to exhibit a superior functionality as an oxygen electrocatalyst and electrode for Li−O 2 batteries compared to its non-holey homologues. The great impact of hybridization-driven vacancy introduction on the electrochemical performance originates from an efficient electrochemical activation of both Fe and Ni ions during electrocatalytic process, a reinforcement of interfacial electronic coupling, an increase in electrochemical active sites, and an improvement in electrocatalysis/charge-transfer kinetics.

A detailed understanding of the surface modification or coating of materials is becoming more important for the design and development of hybrid materials for their advanced applications.