Battery separator coating material, preparation method therefor and use thereof

Provided is a method for preparing a battery separator coating material, the method comprising: dissolving PVDF and a covalent organic backbone material in an organic solvent and stirring same until uniform. The mass ratio of the PVDF to the covalent organic backbone material to N-methylpyrrolidone is 20:(70-85):(5-10). When the material is applied to preparation of a lithium ion battery separator, the problem of metal dissolution when a transition metal oxide is used as a positive electrode material can be effectively solved. The prepared separator can effectively adsorb metal ions and prevent the metal ions from being deposited on a negative electrode during charging and discharging processes, such that the cycle performance of a transition metal oxide positive electrode material is improved.