▎ 摘　　要

NOVELTY - Silicon-carbon composite material comprises a core composite material and a soft carbon layer coated on the surface of the inner core composite materials. The inner core composite material is a carbon nanotubes/silica/graphene composite material. USE - The silicon carbon cathode material is useful for lithium ion battery in portable electronic device e.g. notebook computer and mobile phone. Can also be used in high power vehicle electric artificial satellite, aerospace and chargeable power supply. ADVANTAGE - The silicon-carbon composite material exhibits excellent electrochemical performance, and has good cycle stability and multiplying power performance; increases the electrolyte solution contact and cathode material contact; shortens the diffusion path of the lithium ion. The outer soft carbon layer is easy to form a stable SEI film with the electrolytes solution. The carbon nano-tube/silicon/graphene composite material has high conductivity and gram capacity, and good application prospect in lithium ion battery cathode the controllability is good, andis suitable for industrial popularization and application. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) a preparation method of silicon-carbon composite material; and (2) a lithium ion battery.