Method for preparing silicon-carbon composite material based on silane cracking method and application of silicon-carbon composite material

The invention discloses a method for preparing a silicon-carbon composite material based on a silane cracking method and application thereof, and the method comprises the following steps: S1) putting petroleum coke and an inorganic carbonic acid compound into a reaction cavity, and heating to a temperature condition not lower than the softening point of the petroleum coke; introducing modified gas, and keeping the temperature for not less than 1 hour; carbonizing at the temperature of 1100-1300 DEG C for at least 1 hour to obtain petroleum coke porous carbon; s2) transferring the petroleum coke porous carbon into a fluidized bed cavity, heating, vacuumizing, introducing silane gas and heteroatom gas, and carrying out vapor deposition to obtain a heteroatom doped silicon carbon precursor material; s3) cooling the heteroatom-doped silicon-carbon precursor material, introducing passivation gas to perform surface passivation treatment, then raising the temperature, and introducing fluorinated gas to perform vapor