| abstract |
The invention discloses a lithium salt-coated graphene-doped silicon-carbon composite material and a preparation method thereof, wherein the preparation method comprises the following steps: firstly, preparing carboxylic acid porous nano-silicon, then soaking the carboxylic acid porous nano-silicon in a solution of a catalyst amino organic solvent, then growing graphene with a vertical structure on the surface of the carboxylic acid porous nano-silicon by a vapor deposition method, finally depositing inorganic lithium salt on the surface of the carboxylic acid porous nano-silicon by a particle injection method, and crushing the inorganic lithium salt to obtain the lithium salt-coated graphene doped silicon-carbon composite material. The prepared composite material vertically grows graphene on the surface of the nanometer silicon by utilizing the action of the catalyst, so that the impedance and the expansion of the graphene are reduced; simultaneously, the carboxylic acid porous nano silicon and the amination solution are subjected to chemical reaction to generate an inner core with a stable structure; the impedance of the graphene is reduced by utilizing the synergistic effect of the electronic conductivity of the graphene and the high ionic conductivity of inorganic lithium salt on the shell of the graphene, and lithium ions can be rapidly inserted and removed through the inorganic lithium salt by depending on the core porous structure of the graphene, so that the quick charging performance is improved, and the expansion is reduced. |