Manganese oxide for aqueous zinc ion battery as well as preparation method and application of manganese oxide

The invention belongs to the field of ion batteries, and particularly relates to manganese oxide for an aqueous zinc ion battery as well as a preparation method and application of the manganese oxide. The magnesium oxide is slightly dissolved in water to slowly form alkaline conditions, so that the reaction process is more controllable and stable, the operation is convenient, the cost is low, the safety coefficient is high, and the method is suitable for mass production. The acidified multi-walled carbon nanotubes can obviously enlarge the battery capacity, the multi-walled carbon nanotubes containing rich hydroxyl groups surround the prismatic beta-MnO2, the surface area of the material is increased, the acidified multi-walled carbon nanotubes can also control the growth direction of the beta-MnO2, the ionic conductivity of the whole material is improved, and the structural collapse of the beta-MnO2 is inhibited. The agglomeration phenomenon is serious due to excessive acidification of the multi-walled carbo