A Bimetallic Oxide ZnMnO₃ as a High-performance Long-cycle Cathode for Zinc Ion Batteries

A bimetallic oxide (ZnMnO₃) is synthesized with the sol-gel method and used as the cathode for zinc ion batteries for the first time. Electrochemical tests show that the ZnMnO₃ exhibits a high specific discharge capacity (175 mA·h/g at 300 mA/g). At a current density of 1 000 mA/g, the specific discharge capacity is still 134 mA ·h/g. Compared with monometallic oxides, the material exhibits more excellent cycling stability and better rate performance. The ex-situ scanning electron microscope (SEM) characterization of the electrode surface morphology shows that the morphology of ZnMnO₃ can be well maintained during the cycling process so that it can have stable long-cycle performance. According to the results of ex-situ X-ray diffraction (XRD) analysis, the zinc storage mechanism of ZnMnO₃ is the insertion and extraction reaction.