A high-capacity high-pressure graphite composite material and a preparation method thereof

The invention relates to a high-capacity high-pressure graphite composite material and a preparation method thereof, belonging to the technical field of negative electrode materials of lithium ion batteries. The high-capacity high-pressure graphite composite material of the invention is a core-shell structure, and the core comprises graphite and graphene doped in graphite. The mass ratio of graphite to graphene is 100: 0.5- 1; The shell comprises a first shell wrapped outside the core and a second shell wrapped outside the first shell, wherein the first shell is lithium silicate and the secondshell is a nitrogen-doped carbon layer; The ratio of the thickness of the core to the thickness of the first housing and the thickness of the second housing is 100: (5 to 10): (0.5 to 2). The lubricating property of the graphene in the core of the material of the invention can improve the compaction density of the material, the good conductivity of lithium ion in the lithium silicate in the shelland the good electronic c