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Promising lithium–oxygen batteries (LOBs) with extra‐high capacities have attracted increasing attention for use in future electric devices. However, the challenges facing this complicated battery system still limit their practical applications. These challenges mainly consist of inefficient product evolution and low‐activity catalysts. In present work, a cation occupying, modified 3D‐architecture NiFeO cubic spinel is constructed via superassembly strategy to achieve a high rate, stable electrocatalyst for LOBs. The octahedron predominant spinel provides a stable polycrystal structure and optimized electronic structure, which dominates the discharge/charge products evolution with multiformation kinetics of crystal Li2O2 and Li2−xO2 at low and high rate conditions and energetically favors the mass transport between the electrode/electrolyte interface. Simultaneously, the porous NiFeO framework provides adequate spaces for Li2O2 accommodation and complex channels for sufficient electrolyte, oxygen, and ion transportation, which dramatically alter the cathode catalysis for an unprecedented performance. As a consequence, a large specific capacity of 23413 mAh g−1 and an excellent cyclability of 193 cycles at a high current of 1000 mA g−1, and 300 cycles at a current of 500 mA g−1, are achieved. The present work provides intrinsic insights into designing high‐performance metal oxide electrocatalysts for Li–O2 batteries with fine‐tuned electronic and frame structure. [ABSTRACT FROM AUTHOR]

While electrochemical water splitting is one of the most promising methods to store light/electrical energy in chemical bonds, a key challenge remains in the realization of an efficient oxygen evolution reaction catalyst with large surface area, good electrical conductivity, high catalytic properties, and low fabrication cost. Here, a facile solution reduction method is demonstrated for mesoporous Co3O4 nanowires treated with NaBH4. The high-surface-area mesopore feature leads to efficient surface reduction in solution at room temperature, which allows for retention of the nanowire morphology and 1D charge transport behavior, while at the same time substantially increasing the oxygen vacancies on the nanowire surface. Compared to pristine Co3O4 nanowires, the reduced Co3O4 nanowires exhibit a much larger current of 13.1 mA cm-2 at 1.65 V vs reversible hydrogen electrode (RHE) and a much lower onset potential of 1.52 V vs RHE. Electrochemical supercapacitors based on the reduced Co3O4 nanowires also show a much improved capacitance of 978 F g-1 and reduced charge transfer resistance. Density-functional theory calculations reveal that the existence of oxygen vacancies leads to the formation of new gap states in which the electrons previously associated with the Co-O bonds tend to be delocalized, resulting in the much higher electrical conductivity and electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Li-O2 Batteries: Interfacial Super-Assembled Porous CeO2/C Frameworks Featuring Efficient and Sensitive Decomposing Li2O2 for Smart Li-O2 Batteries (Adv. This technique is highly applicable to the future production of smart high-performance Li-O SB 2 sb batteries with CeO SB 2 sb -based cathode catalysts. Carbon materials, cathode materials, Li-O2 batteries, porous materials, self-assembled. [Extracted from the article]

The Li–O2 battery (LOB) represents a promising candidate for future electric vehicles owing to its outstanding energy density. However, the practical application of LOB cells is largely blocked by the poor cycling performance of cathode materials. Herein, an ultralong 440‐cycle life of an LOB cell is achieved using CeO2 nanocubes super‐assembled on an inverse opal carbon matrix as the cathode material without any additives. CeO2 is proved to be effective for the complete and sensitive decomposition of loosely stacked Li2O2 films during the oxygen evolution reaction process and full accommodation of volume changes caused by the fast growth of Li2O2 films during the oxygen reduction reaction process. The super‐assembled porous CeO2/C frameworks satisfy critical requirements including controlled size, morphology, high Ce3+/Ce4+ ratio, and efficient volume change accommodation, which dramatically increase the cycle life of LOB cell to 440 cycles. This study reveals the design strategy for high performance CeO2 catalyst cathodes for LOB cells and the generation mechanisms of Li2O2 films during the discharge process by using density functional theory calculations, showing new avenues for improving the future smart design of CeO2‐based cathode catalysts for Li–O2 batteries. [ABSTRACT FROM AUTHOR]

Direct electrochemical production of hydrogen peroxide (H2O2) through two‐electron oxygen electrochemistry, for example, the oxygen reduction in fuel cells or water oxidation in water electrolyzers, could provide an attractive alternative to locally produce this chemical on demand. The efficiency of these processes depends greatly on the availability of cost‐effective catalysts with high selectivity, activity, and stability. In recent years, various novel nanostructured materials have been reported to selectively produce H2O2. Through combined experimental and theoretical approaches, underlying mechanisms in the electrochemical synthesis of H2O2 via oxygen electrochemistry have been unveiled. Considering the remarkable progress in this area, the authors summarize recent developments regarding the direct production of H2O2 through two‐electron electrochemical oxygen reactions. The fundamental aspects of electrochemical oxygen reactions are first introduced. Various types of catalysts that can effectively produce H2O2 via two‐electron oxygen electrochemistry are then presented. In parallel, the unique structure‐, component‐, and composition‐dependent electrochemical performance together with the underlying catalytic mechanisms are discussed. Finally, a brief conclusion about the recent progress achieved in electrochemical generation of H2O2 and an outlook on future research challenges are given. Direct electrochemical production of hydrogen peroxide (H2O2) through two‐electron oxygen reduction and water oxidation is summarized. The structure, components, and composition of the electrocatalysts show strong correlation with their selectivity, activity, and durability. This review also provides some guidelines for rational design of highly efficient electrocatalysts toward electrochemical H2O2 generation on demand. [ABSTRACT FROM AUTHOR]