The invention relates to a preparation method of a
silicon carbon negative
electrode material for
lithium ion batteries. The preparation method is characterized in that the preparation technology specifically comprises the following preparation steps: through expanded
graphite pretreatment, precursor turbid liquid configuration, precursor preparation and
silicon-enriched material preparation, sufficiently mixing a
silicon-enriched material with other negative
electrode carbon materials of
lithium batteries, and obtaining the silicon carbon negative
electrode material through ball-milling, wherein the silicon-enriched material accounts for 10% to 30% of total
mass, and the other negative electrode carbon materials of
lithium batteries comprise synthetic
graphite. According to the method, silica
powder is not used as a silicon source, on one hand, the material cost is reduced, and on the other hand, the
insertion of silicon among expanded
graphite layers is guaranteed, so that the buffer action of expanded graphite on silicon is guaranteed; and moreover, the method uses the other negative electrode carbon materials as a main
carbon source, so that the flexibility of the material is improved, the cost is reduced, batch is easily realized, and the
controllability of cost and performance are reached.