▎ 摘　　要

NOVELTY - Preparing potassium ion battery cathode material, comprises (i) adding graphite powder to concentrated sulfuric acid, stirring, cooling under an ice-water bath to obtain uniform mixture, adding sodium nitrate and potassium permanganate into it, and reacting to obtain mixed slurry I, (ii) adjusting mixed slurry I to certain temperature, continuing stirring, adding deionized water, and mixing to obtain mixed slurry II, (iii) heating mixed slurry II, stirring, adding deionized water and hydrogen peroxide, and mixing to obtain mixed slurry III, (iv) cooling mixed slurry III, washing off inorganic salts by centrifugation, removing potassium-containing inorganic salt solution adsorbed on the surface of graphene film in the mixed slurry III to obtain slurry graphite oxide, (v) cooling and drying the slurry graphite oxide to obtain dry graphite oxide solid, namely honeycomb graphite oxide, and (vi) carrying out heat treatment to the honeycomb graphite oxide to obtain pyrolytic carbon. USE - The method is useful for preparing potassium ion battery cathode material. ADVANTAGE - The method adopts multi-step densification method to prepare the carbon material for potassium ion battery, and the cathode material has excellent electrochemical performance. DETAILED DESCRIPTION - Preparing potassium ion battery cathode material, comprises (i) adding graphite powder to concentrated sulfuric acid with concentration of 98%, stirring, cooling under the condition of an ice-water bath for 30-60 minutes, forming uniform mixture, adding sodium nitrate and potassium permanganate into it, and reacting to obtain mixed slurry I, (ii) adjusting the mixed slurry I to a certain temperature, continuing stirring, slowly adding deionized water, and mixing evenly to obtain mixed slurry II, (iii) heating the mixed slurry II, stirring continuously for 30-60 minutes, adding deionized water and hydrogen peroxide, and mixing evenly to obtain mixed slurry III, (iv) cooling the mixed slurry III to room temperature, washing off inorganic salts in it by centrifugation under normal temperature conditions, removing potassium-containing inorganic salt solution adsorbed on the surface of graphene film in the mixed slurry III to obtain slurry graphite oxide, (v) cooling and drying the slurry graphite oxide to obtain dry graphite oxide solid, namely honeycomb graphite oxide, and (vi) carrying out heat treatment to the honeycomb graphite oxide to obtain pyrolytic carbon. An INDEPENDENT CLAIM is also included for preparing potassium ion battery cathode using pyrolytic carbon material.