In-Situ growth of MnO2 nanoflakes on Co3V2O8 generating a hollow hexahedron: Zn-storage properties, and investigation of electrochemical mechanism

Composite heterostructured electrode materials are of dominant significance for improving the electrochemical performance of advanced energy storage devices. In this work, a hollow heterostructure Co3V2O8@MnO2 was obtained by a simple hydrothermal method and an In-situ growth strategy as a free-standing aqueous zinc-ion batteries cathode. The heterojunction material itself has high conductivity, and the hollow structure can largely prevent the volume shrinkage/expansion of MnO2. In addition, MnO2 Nanoflakes can also provide sufficient active sites for the electrolyte. Specifically, such Co3V2O8@MnO2 cathode exhibit a relatively high discharge capacity of 245.4 mAh·g−1 at 100 mA·g−1, desirable rate performance, and the discharge capacity is about 140.0 mAh·g−1 at a current density of 300 mA·g−1 after 300 cycles. The application in aqueous zinc-ion batteries suggests that the method of designing Co3V2O8@MnO2 hollow heterostructures can become a reasonable idea for creating high-performance aqueous zinc-ion batteries cathodes.