Preparation method of self-assembled ball-flower type cathode material for lithium ion battery

The invention relates to a preparation method of a self-assembled ball-flower type cathode material for a lithium ion battery. The preparation method comprises the following steps: dissolving ammonium metavanadate in ethylene glycol; then adding deionized water and uniformly stirring to obtain a NH4VO3 solution with the concentration of NH4 of 0.10-0.30mol/L; after adjusting the pH value and heating at 60-90 DEG C or carrying out ultrasonic treatment at 1000-1500W to obtain a suspension; and then after centrifugal separation, heating for 1-3 hours. The prepared material V2O5 is microcrystalline and is uniform in chemical composition, relatively high in purity and uniform in shape. Moreover, the prepared V2O5 is a loose structure which is formed by self-assembling nanorods, wherein the diameter of the nanorods is about 50nm and the length of the nanorods is about 1 micron. The cathode material has a relatively large specific surface area, so that not only can the contact area with an electrolyte be effectively increased, but also the diffusing path of lithium ions can be shortened due to the structures of the short nanorods, thereby promoting transmission of the lithium ions and improving the electrochemical performance of the material.