Modified graphite and preparation method thereof, lithium battery negative electrode material, lithium battery negative electrode plate and lithium battery

The invention provides modified graphite and a preparation method thereof, a lithium battery negative electrode material, a lithium battery negative electrode plate and a lithium battery. The preparation method of the modified graphite comprises the following steps of carrying out oxidation pretreatment on graphite to obtain pretreated graphite, performing complex reaction on a mixture containing the pretreated graphite and the hydroxyl-containing polymer and zinc chloride, and then drying to obtain a precursor, and carrying out carbonization treatment on the precursor to obtain the modified graphite. Oxidation pretreatment is carried out on graphite, complex reaction is then carried out on the graphite, the mixture of the hydroxyl-containing polymer and zinc chloride, drying is conducted to obtain a gelatinous precursor, and the precursor is carbonized to obtain porous modified graphite with a core-shell structure of sp2 + sp3 amorphous carbon coated sp2 graphite; when the modified graphite is applied to the