Vanadium pentoxide and rGO co-coated gradient ternary positive electrode material and preparation method thereof

Abstract

The invention discloses a vanadium pentoxide and rGO co-coated gradient ternary positive electrode material and a preparation method thereof. The positive electrode material is spherical core-shell structure particles formed by coating lithium nickel cobalt manganate on the inner and outer layers of vanadium pentoxide and rGO. The mass ratio of the lithium nickel cobalt manganate to the vanadium pentoxide to the rGO is 1: (0.01-0.05): (0.01-0.05). The chemical formula of the lithium nickel cobalt manganate is LiNixCoyMn(1-x-y)O2, x is greater than or equal to 0.70 and less than or equal to 0.90, y is greater than or equal to 0.05 and less than or equal to 0.2, and 1-x-y is greater than 0. The invention also discloses a preparation method of the vanadium pentoxide and rGO co-coated gradientternary positive electrode material. The positive electrode material is high in lithium ion and electron conductivity and good in electrochemical performance. The method is simple, controllable, short in process, low in cost and suitable for industrial production.

Description

technical field [0001] The invention relates to a ternary positive electrode material and a preparation method thereof, in particular to a gradient ternary positive electrode material co-coated with vanadium pentoxide and rGO and a preparation method thereof. Background technique [0002] High nickel ternary materials are currently one of the most attractive cathode materials due to their high theoretical specific capacity and high mass specific energy. However, high-nickel ternary materials still have problems such as poor cycle stability and insufficient rate performance during the charge-discharge cycle, and the surface of the material is easily corroded by HF, which affects the stability of the material structure. At the same time, the Ni on the surface of the material 4+ Ions are easily reduced to rock-salt phase NiO, which greatly affects the conductivity of the material. Researchers have conducted modification experiments on high-nickel ternary materials, especially ...

AI Technical Summary

Problems solved by technology

However, 1) the preparation of ternary material precursors by hydrothermal method is not suitable for widespread use; 2) the dissolution of ammonium metavanadate in the solution cannot guarantee the complete conversion of vanadium pentoxide; 3) the ternary precursors are complexed with lithium and vanadium Source co-firing will affect the structure of ternary materials

Therefore, this method is only applicable to the experimental process, and the synthesis process is relatively complicated and needs to be further improved.

[0004] CN109546123 A discloses a vanadium pentoxide-coated core-shell structure gradient nickel-cobalt-manganese positive electrode material and a preparation method thereof. During the process of high temperature treatment, if metal ions and electrons diffuse at the core-shell interface, it will form a barrier that hinders the diffusion and greatly reduce the performance of the material.

Images