Silicon-carbon composite material and preparation method thereof, and lithium ion battery

The invention provides a silicon-carbon composite material and a preparation method thereof, and a lithium ion battery. The method comprises the following steps: mixing calcium lignosulphonate, gelatin and deionized water according to a first specified mass ratio to obtain a mixed solution A; mixing the mixed solution A with nano-silicon according to a second specified mass ratio, and ultrasonically dispersing for a first specified time to obtain a mixed solution B; carrying out spray drying on the mixed solution B according to a specified spray drying process to obtain a primary carbon-coatednano-silicon composite material; and carbonizing the primary carbon-coated nano-silicon composite material in an inert gas atmosphere according to a specified carbonization process to obtain the silicon-carbon composite material. Calcium lignosulphonate and gelatin are used as carbon sources, and nano silicon is used as a silicon source, so that the production process is simple and pollution-freeto operate, the finished