MICROCAPSULE TYPE SILICON-CARBON COMPOSITE NEGATIVE ELECTRODE MATERIAL, AND PREPARATION METHOD THEREFOR AND APPLICATION THEREOF

摘要

Disclosed is a microcapsule type silicon-carbon composite negative electrode material. The negative electrode material comprises a current collector and a silicon-carbon coating which is formed by drying silicon-carbon slurry with which the current collector is coated; the silicon-carbon slurry comprises carbon slurry and silicon capsule powder dispersed in the carbon slurry; the carbon slurry comprises a dispersing agent, and a carbon material, a first conductive agent, and a first binder dispersed in the dispersing agent; the silicon capsule powder comprises silicon powder and a second binder with which the surface of the silicon powder is coated; a microcapsule structure is formed between the second binder and the silicon powder coated by the second binder; and the first binder is different from the second binder. The improved silicon-carbon composite negative electrode material in the present invention has excellent cycle performance, coulombic efficiency, and rate capability.