The invention discloses a preparation method of an N-
doped graphene-coated
silicon-based negative
electrode material, which comprises the following steps of: performing
carbon coating by using
graphene, controlling the particle size of a
silicon substrate to be less than 2 microns, and realizing micro-nanocrystallization of a
silicon main body material through mechanical ball milling, so that the micro-nanocrystallization silicon material is distributed in a
graphite layer while
metal-doped
silicon monoxide obtains a smaller particle size; according to the preparation method,
metal doped
silicon monoxide is taken as a silicon source, the surface of the
metal doped
silicon monoxide is coated with the stripped
graphene, the
metal doped silicon
monoxide is coated with the
graphene oxide, finally, a silicon material is further uniformly coated with graphene micro-nanosheets by adopting a rapid
spray drying technology, and an electroactive substance is effectively protected from being influenced by
volume change caused in the charging and discharging process through the synergistic effect of the graphene micro-nanosheets. The preparation method has the advantages that after the
composite material is prepared from micron-sized silicon
monoxide and graphene, low-cost preparation of the modified silicon
monoxide is realized, the
electrode material with excellent electrochemical performance is obtained, the stability of the
composite material is effectively improved, the cycle service life is prolonged, and the application and popularization value is relatively good.