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Metal‐air batteries as alternatives to the existing lithium‐ion battery are becoming increasingly attractive sources of power due to their high energy‐cost competitiveness and inherent safety; however, their low oxygen evolution and reduction reaction (OER/ORR) performance and poor operational stability must be overcome prior to commercialization. Herein, it is demonstrated that a novel class of hydrothermally grown dual‐phase heterogeneous electrocatalysts, in which silver‐manganese (AgMn) heterometal nanoparticles are anchored on top of 2D nanosheet‐like nickel vanadium oxide (NiV2O6), allows an enlarged surface area and efficient charge transfer/redistribution, resulting in a bifunctional OER/ORR superior to those of conventional Pt/C or RuO2. The dual‐phase NiV2O6/AgMn catalysts on the air cathode of a zinc‐air battery lead to a stable discharge–charge voltage gap of 0.83 V at 50 mA cm−2, with a specific capacity of 660 mAh g−1 and life cycle stabilities of more than 146 h at 10 mA cm−2 and 11 h at 50 mA cm−2. The proposed new class of dual‐phase NiV2O6/AgMn catalysts are successfully applied as pouch‐type zinc‐air batteries with long‐term stability over 33.9 h at 10 mA cm−2.

Given the global demand for green energy, the battery industry is positioned to be an important future technology. Lithium-ion batteries (LIBs), which are the most widely used battery in the market, are the focus of various research and development efforts, from materials to systems, that seek to improve their performance. The separator is one of the core materials in LIBs and is a significant factor in the lifespan of high-performance batteries. To improve the performance of present LIBs, electrochemical testing and related surface analyses of the separator is essential. In this paper, we prepared a ceramic (Boehmite, γ-AlOOH) coated polypropylene separator and a porous polyimide separator to compare their electrochemical properties with a commercialized polypropylene (PP) separator. The prepared separators were assembled into nickelmanganese-cobalt (NMC) cathode half-cell and full-cell lithium-ion batteries. Their cycling performances were evaluated using differential capacity and electrochemical impedance spectroscopy with ethylene carbonate:dimethylcarbonate (EC:DMC) electrolyte. The ceramic coated polypropylene separator exhibited the best cycle performance at a high 5 C rate, with high ionic conductivity and less resistive solid electrolyte interphase. Also, it was confirmed that a separator solid electrolyte interface (SSEI) layer formed on the separator with cycle repetition, and it was also confirmed that this phenomenon determined the cycle life of the battery depending on the electrolyte.