COMPOSITE SILICON MATERIAL AND PREPARATION METHOD THEREFOR, NEGATIVE ELECTRODE PLATE, SECONDARY BATTERY, AND ELECTRICAL APPARATUS

The composite silicon material includes an inner core and a silicon-containing cladding layer cladded on the outer side of the inner core. The inner core comprises a silicon-carbon material, the silicon-carbon material includes a porous conductive material and a first silicon-based material, the outer surface of the porous conductive material has pores, and at least a portion of the first silicon-based material is distributed in the pores. The silicon-containing cladding layer contains an ion-conducting material and a second silicon-based material. The second silicon-based material is dispersed in the ion-conducting material. At least a portion of the first silicon-based material is embedded in the pores of the porous conductive material, which can effectively alleviate the problem of silicon expansion; meanwhile, the ion-conducting material can increase the ion transmission path, thereby effectively alleviating the problem of poor dynamic performance caused by the small number of ion transmission paths of the silicon-carbon material.