Silicon-carbon composite negative electrode material and preparation method and application thereof

The invention belongs to the technical field of negative electrode materials for lithium ion batteries, and particularly relates to a silicon-carbon composite negative electrode material as well as a preparation method and application thereof. The silicon-carbon composite negative electrode material has a core-shell structure. The silicon-carbon composite negative electrode material comprises amorphous carbon, porous carbon and a silicon nanosheet, the silicon nanosheet is a core material, the porous carbon and the amorphous carbon are shell materials, and a cavity exists between the core material and the shell material. According to the method, the problem of volume expansion of the silicon-carbon composite negative electrode material can be well solved, and meanwhile, the cycle performance and the first coulombic efficiency of the silicon-carbon composite negative electrode material can also be improved. 本发明属于锂离子电池用负极材料技术领域，具体涉及一种硅碳复合负极材料及其制备方法与应用。所述硅碳复合负极材料具有核壳结构。所述硅碳复合负极材料包括无定型炭、多孔炭和硅纳米片；所述硅纳米片为核芯材料，所述多孔炭