The invention discloses a preparation method for a
silicon-carbon composite negative
electrode material. The preparation method comprises the steps of performing dispersing on nanometer
silicon,
graphite and an
organic matter separately and mixing in proportion; next, performing heating and
drying and heating until the temperature reaches an
organic matter softening point temperature or above, and performing fusing and binding and low-temperature
carbonization to obtain an
organic matter cracked carbon-coated primary
coating material; performing dispersing on the organic matter and the primary
coating material separately and mixing in proportion; and next, performing heating and
drying and heating until the temperature reaches an organic matter
softening point temperature or above, and performing fusing and
coating and high-temperature
carbonization to obtain an organic matter cracked carbon-coated secondary coating material, namely the
silicon-carbon composite negative
electrode material provided by the invention. The initial reversible capacity of the negative
electrode material prepared by the method can reach 649mAh / g, and the capacity
retention ratio after 50 cycles can be maintained at 85.36%, and quite excellent
cycling performance is shown; and in addition, the preparation method has a simple and environment-friendly process, low
energy loss, rich silicon and
graphite raw material resource, low cost and high safety, and is suitable for industrial production and use.