MnO2 particles grown on the surface of N-doped hollow porous carbon nanospheres for aqueous rechargeable zinc ion batteries

The growing demand for energy storage devices leads to great interest in advanced batteries researches. Among them, aqueous rechargeable zinc ion batteries (ARZIBs) has attracted wide attention due to their low cost, simple manufacturing process and environmental friendliness. Here, we prepared a composite material, namely MnO2 particles grown on the surface of N-doped hollow porous carbon nanospheres, that is, combining hollow carbon material with metal oxides, and employed it as the cathode of ARZIBs. Owing to the synergistic merits of desirable structural features of manganese oxides and hollow porous carbon nanospheres, the composite material exhibited excellent performance for the storage of zinc ions, including high capacity of 206 mA h g−1 at 100 mA g−1, impressive rate capability of 103 mA h g−1 at 500 mA g−1 and superior cycling stability with the coulombic efficiency (capacity retention) of 98.3% over 650 cycles. The distinguished electrochemical behavior is attributed to the synergistic effects of desirable structural features of manganese oxides and hollow porous carbon nanospheres, which can be summed up as larger electron modified interface, high mass loading, and stable carbon-layer structure. These results demonstrate that the composite material could satisfy the criteria for applying in advanced ARZIBs.