The invention relates to the field of
lithium batteries, and discloses a
boron doped modified soft
carbon coating negative
electrode material with high stability under a high-low temperature environment and a preparation method thereof. An
amorphous carbon-carbon lay is formed on that surface of a negative
electrode substrate aft
carbonization by a soft
carbon source,
boron oxide is generated by decomposing a
boron compound at a high temperature, the reaction of the
boron oxide with the
amorphous carbon and the surface of the negative
electrode substrate is controlled, and a
composite structure such as a boron-carbon bond and a boron-carbon-
oxygen bond is for on the surface of the negative
electrode material at a high temperature. 1, that soft carbon coat can reduce the impedance of the material under the low temperature, improve the liquid absorption performance, increase the low-temperature
discharge voltage platform and greatly improve the low-temperature performance of the material; 2. By the
catalysis of boron, the degree of graphitization of the
cathode material is increased by reducing the surface defects, so that the specific surface area is greatly reduced, and the
side reaction of the
cathode material with the
electrolyte at high temperature is reduced by the smaller specific surface area, and the performance at high temperature is obviously improved.