A lithium ion battery silicon-carbon composite negative electrode material preparation and their products

The present invention relates to a lithium ion battery silicon-carbon composite negative electrode material preparation and their products. Belonging to the technical field of lithium ion battery anode material. The method comprises the steps of: a silicon alloy powder is added to the acid solution until the alloy was completely dissolved, washed with deionized water, placed in an HF solution was stirred, washed with deionized water again, and dried in vacuo, re-dispersed in a dispersant, to prepare a dispersion liquid silica fume; graphite, a binder, silica fume mixed dispersion; secondary drying in vacuo; carbonization; carbonized product was placed in a dispersing agent, the capping agent is added, mix well; three times and dried in vacuo; two charring times. The present invention is a double-coated adhesive relieve mechanical stress model structure of silicon during charge and discharge due to volumetric expansion and contraction, the elimination volume effect.