A bimetallic oxide NiMnO3 with perovskite structured as a high-performance cathode for zinc ion batteries

Rechargeable aqueous zinc ion batteries (ZIBs) are considered as one of the most promising candidates for large-scale energy storage due to their high safety, environmental benignity, and low cost. Developing cathode materials with high specific capacity and long cycle performance is the key to the commercialization of ZIBs. In this work, a perovskite structured bimetallic oxide (NiMnO3) was synthesized and firstly used as cathode for ZIBs. Electrochemical tests show that the NiMnO3 exhibits a high capacity (280 mA h g−1 at 300 mA g−1), good cycling stability, and rate performance (152 mA h g−1 at 1000 mA g−1). The fast ion transportation and the significant capacitance contribution should be the reasons for remarkable rate performance. The zinc storage mechanism of NiMnO3 is the insertion and extraction reaction and the formation/dissolution of ZHS (ZnSO4·3Zn(OH)2·5H2O). The results suggest that the bimetallic oxide with perovskite structure could be a promising cathode material for ZIBs.