▎ 摘　　要

NOVELTY - A core-shell structure type graphene composite material preparation method involves mixing iron salt and graphene and ultrasonically dispersing the mixture into de-ionized water to obtain the uniform mixed solution. Alkali solution is added into the mixed solution. The mixed liquid is put into a reaction kettle. The obtained product is washed after the reaction is finished. The washed product is frozen and dried in vacuum at 500-900 degrees C for 6-36 hours, and cooled to room temperature to obtain the iron doped ferric oxide core-shell structure type graphene composite material. USE - Method for preparing a core-shell structure type graphene composite material that is utilized as a cathode material of a lithium ion battery. ADVANTAGE - The method enables preparing the core-shell structure type graphene composite material in a simple, safe and eco-friendly manner with good structural stability and monodispersity, and improving cycle life, multiplying power performance, and charging and discharging performance of the battery. DETAILED DESCRIPTION - A core-shell structure type graphene composite material preparation method involves mixing iron salt and graphene and ultrasonically dispersing the mixture into de-ionized water for 25-180 minutes to obtain the uniform mixed solution. Alkali solution is added into the mixed solution and the pH value of the solution is adjusted to 5-11. The mixed liquid is put into a reaction kettle at a temperature of 120-230 degrees C for 6-48 hours. The obtained product is washed with de-ionized water and absolute ethyl alcohol for several times, after the reaction is finished. The washed product is frozen and dried in vacuum at 500-900 degrees C for 6-36 hours, and cooled to room temperature to obtain the iron doped ferric oxide core-shell structure type graphene composite material.