Modified graphite negative electrode material and preparation method and application thereof

The invention discloses a modified graphite negative electrode material as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) carrying out ball milling on graphite until the particle size D50 is 10-20 microns; (2) placing the ball-milled graphite in a mixed solution of ethylenediamine and ammonia water, stirring at 50-80 DEG C for 1-5 hours, filtering, and taking out graphite particles; and (3) putting the graphite particles into a coating agent, carrying out hydrothermal reaction for 1-5 hours, and then cooling to room temperature. The graphite negative electrode material with improved coating performance, which is good in coating performance, large in charge and discharge capacity, high in lithium removal specific capacity, high in graphitization degree and long in cycle life, is prepared, and a battery prepared from the graphite negative electrode material is large in capacity and high in charge and discharge specific capacity. 本发明公开了一种改性石墨负极材料及其