Nano-silicon agglomerate composite negative electrode material and method for preparing the same

A method for preparing a nano-silicon agglomerate composite negative electrode material, characterized in that it comprises the following steps:

• (1) performing a surface metal replacement reaction by placing a powder of metal A in a salt solution of metal B, to produce nano-sized metal B particles on a part of the surface of the powder of metal A, thereby forming a composite powder;
• (2) continuously charging the composite powder serving as a reactant and a nucleating agent into a reaction chamber;
• (3) carrying a SiCl4 gas into the reaction chamber with inert gas or nitrogen;
• (4) performing a high temperature reaction with continuous stirring by setting the temperature of the reaction chamber to be 500 to 950° C., the reaction causing a nano-silicon agglomerate of pine needle and branch-shaped three-dimensional network structure to dynamically grow and wind around the nano-sized metal B particles;
• (5) subjecting the nano-silicon agglomerate of pine needle and branch-shaped three-dimensional network structure discharged from the reaction chamber to a vacuum thermal treatment;
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• (6) subjecting the nano-silicon agglomerate of pine needle and branch-shaped three-dimensional network structure obtained in step (5) to a composite coating treatment with electrically conductive carbon and an inorganic metal oxide.

A Method for preparing a nano-silicon agglomerate composite negative material, characterized in that it comprises the following steps:

• (1) continuously charging an alloy powder comprising metal A and carbon and serving as a reactant and a nucleating agent into a reaction chamber;
• (2) carrying a SiCl4 gas into the reaction chamber with inert gas or nitrogen;
• (3) performing a high temperature reaction with continuous stirring by setting the temperature of the reaction chamber to be 500 to 950° C., the reaction causing a nano-silicon agglomerate of pine needle and branch-shaped three-dimensional network structure to dynamically grow and wind around the nano-sized carbon particles produced by the alloy powder;
• (4) subjecting the nano-silicon agglomerate of pine needle and branch-shaped three-dimensional network structure discharged from the reaction chamber to a vacuum thermal treatment;
• and
• (5) subjecting the nano-silicon agglomerate of pine needle and branch-shaped three-dimensional network structure obtained in step (4) to a composite coating treatment with electrically conductive carbon and an inorganic metal oxide.