Bismuth oxyfluoride/nickel hydroxide secondary alkaline battery and preparation method thereof

The invention discloses a bismuth oxyfluoride/nickel hydroxide secondary alkaline battery and a preparation method thereof. The bismuth oxyfluoride /nickel hydroxide secondary alkaline battery takes nickel hydroxide as a battery positive electrode material, bismuth oxyfluoride as a battery negative electrode material and an alkaline water solution as an electrolyte. A preparation method of the bismuth oxyfluoride comprises: dissolving a soluble bismuth raw material into a solvent or dissolving an insoluble bismuth raw material into acid to prepare a bismuth ion solution; or adding a bismuth raw material with a solubility product which is greater than that of the bismuth oxyfluoride into a solvent to prepare a solid-liquid mixture containing bismuth; or adding a certain amount of a regulator into a bismuth-containing system; or adding a certain amount of a carbon material into the bismuth-containing system again; then adding a certain amount of a fluorine ion solution into the bismuth-containing system to react to generate the bismuth oxyfluoride, wherein the prepared bismuth oxyfluoride is composed of nanosheets with the size of 3nm to 30nm. According to the battery prepared by the invention, the specific capacity is 227mAh/g when the current density is 0.5A/g. The bismuth oxyfluoride/nickel hydroxide secondary alkaline battery and the preparation method thereof have the advantages of simple preparation process, environment friendliness and good electrochemical performances of the battery.