The invention relates to a uniform carbon-coated mesoporous
silicon carbon negative
electrode material and a preparation method and application thereof.The preparation method comprises the steps that a product obtained after
pyrolysis and
carbonization of a
biomass carbon source is subjected to alkali activation treatment, acid
pickling,
drying, smashing,
passivation,
water washing and
drying are conducted to obtain a
mesoporous carbon matrix, nanometer
silicon particles are deposited in pores of the
mesoporous carbon matrix, and the uniform carbon-coated mesoporous
silicon carbon negative
electrode material is obtained. Then selecting a low-temperature
carbonization material and
polyethylene glycol to perform pre-
carbonization and complete carbonization treatment on the mesoporous silicon carbon material to obtain a
carbon coating layer, and finally obtaining the uniform carbon-coated mesoporous silicon carbon negative
electrode material. When the uniform carbon-coated mesoporous silicon carbon negative
electrode material is applied to a
lithium battery, the mesoporous skeleton can effectively inhibit
volume expansion of silicon in a battery circulation process, and the uniform carbon-coated layer can effectively reduce the risk of direct contact between the negative
electrode material and an
electrolyte, so that a stable SE I film is formed to reduce the occurrence of side reactions; and the first coulombic efficiency and the cycle performance of the battery are further improved.