The application discloses a
silicon-carbon
composite material and a preparation method and application thereof, and belongs to the technical field of
lithium ion batteries. The
silicon-carbon
composite material is composed of the following components:
graphite or
graphite-like carbon framework,
silicon particles dispersed in the carbon framework, and an outermost
carbon coating layer; the
carbon coating layer encapsulates the silicon particles in the interior. The carbon framework is formed by high-temperature transient
sintering of
elemental carbon material, the silicon particles are formed by melting and spreading of silicon
powder, and the
carbon coating layer is formed by transient
cracking of carbon hydrates; the high-temperature transient
sintering, melting and spreading and transient
cracking are completed in one step in the same device. The application has the advantages of simple production process, easy operation of equipment, one-step completion of silicon refining and carbon
coating, continuous process, low cost of required raw materials, and easy popularization. Two different carbon sources play the roles of framework and bonding and
coating, so that the silicon is stably encapsulated in the carbon material, the destruction of the
electrode structure caused by the
volume expansion of the silicon is effectively relieved, and good cycle performance is exhibited.