Sodium/potassium ion battery negative electrode material and preparation method thereof

The invention relates to the technical field of battery materials, in particular to a sodium/potassium ion battery negative electrode material and a preparation method thereof. The preparation method comprises the following steps: preparing a mixed aqueous solution of zinc salt and a surfactant and a cobalt cyanide salt solution; adding a cobalt cyanide salt solution into the mixed solution in an ice bath, stirring, standing, collecting a precipitate, and freeze-drying; grinding the precipitate, and carbonizing under an inert gas condition; and washing the carbonized product, and carrying out vacuum drying to obtain the sodium/potassium ion battery negative electrode material. According to the prepared negative electrode material, the cobalt nanoparticles are uniformly dispersed and tightly wrapped in the nitrogen-doped graphite carbon through the strong chemical action of Co-N bonds, a core-shell structure is constructed, the dispersed cobalt nanoparticles can regulate and control charge distribution, the el