Silicon/carbon composite cathode material for lithium ion battery, in-situ preparation method for silicon/carbon composite cathode material and application thereof

The invention discloses a method for preparing a silicon/carbon composite cathode material for a lithium ion battery and a process for preparing two types of pole pieces, and belongs to the technical field of lithium ion battery materials. The method and the process have the advantages that carbon materials are added in procedures for synthesizing nanometer silicon from acid or alkali etched metal-silicon alloy powder, accordingly, nanometer silicon particles can be directly precipitated and can grow on the surfaces of the carbon materials, and silicon/carbon composite materials can be formed in an in-situ manner by one step and can be applied to the cathode material for the lithium ion battery; the dispersibility of the silicon particles can be improved by the aid of the added carbon materials, the conductivity among the silicon particles further can be enhanced, and destruction on the cathode material due to volume expansion of the silicon particles in charge and discharge procedures can be relieved; the composite cathode material manufactured by the aid of the method is high in capacity and coulomb efficiency and excellent in cycle and rate performance; the process is simple and is convenient to implement and low in raw material cost and production cost, and large-scale industrial production can be facilitated.