Gradient high-nickel single-crystal ternary material, preparation method thereof and battery using same

Abstract

The invention relates to a lithium ion battery positive electrode material, and particularly provides a preparation method of a gradient high-nickel single-crystal ternary material. The preparation method comprises the following steps of: (1) taking nanoscale high-nickel ternary material particles as crystal nucleuses; (2) carrying out a first coprecipitation reaction on the crystal nucleuses and a first nickel-cobalt-manganese-containing solution, adding a second nickel-cobalt-manganese-containing solution into the solution after the first coprecipitation reaction is completed, carrying out a second coprecipitation reaction, and carrying out coprecipitation reactions for n times according to the method, wherein the nickel content in the first nickel-cobalt-manganese-containing solution to the nth nickel-cobalt-manganese-containing solution is reduced in a gradient manner, and the manganese content is increased in a gradient manner; and (3) mixing the product of the nth coprecipitation reaction, a lithium source and the crystal nucleuses, and calcining the mixture in an oxygen-containing atmosphere. The gradient high-nickel single-crystal ternary material prepared by adopting the method has an obvious single-crystal form, the structural strength of ternary material particles is effectively improved, the residual alkali amount on the surface of the material is reduced, and the discharge capacity and the cycle performance of a battery can be effectively improved when the gradient high-nickel single-crystal ternary material is applied to the battery.

Description

technical field [0001] The invention relates to a positive electrode active material of a lithium ion battery, in particular to a gradient high-nickel single crystal ternary material, a preparation method thereof and a battery using the material. Background technique [0002] With the rapid development of new energy vehicles in recent years, high energy density, long cycle life, high safety performance, and low cost have become the core issues of concern for battery and material related companies. Ternary materials have become the target of many companies because of their advantages such as high specific capacity, good capacity retention rate, and high-voltage charging performance. Among them, high-nickel ternary materials are more popular because they greatly increase the energy density of materials. became the focus of everyone's attention. [0003] At present, the high-nickel ternary materials on the market are mostly composed of secondary particles, which exist in the f...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the low compaction density of high-nickel ternary materials in the prior art, which are easily broken during the preparation of electrode sheets and charge-discharge cycles, and then The problem of poor cycle performance and safety performance of the battery is provided. A gradient high-nickel single crystal ternary material and its preparation method and a battery using the material are provided. The ternary material forms a single crystal form and effectively improves the structure of the ternary material particles. Strength, and reduce the amount of residual alkali on the surface of the material, using it in batteries can effectively improve the cycle performance and safety performance of batteries

Images