Preparation method of core-shell structure ternary positive electrode material precursor

Abstract

The invention discloses a preparation method of a core-shell structure ternary positive electrode material precursor. The preparation method comprises the following steps: (1) preparing a metal salt solution, a precipitator solution, a complexing agent solution and an amphoteric polymeric flocculant solution; (2) adding water, a complexing agent solution and a precipitator solution into a reaction kettle to prepare a reaction kettle base solution; and (3) adding a metal salt solution, a precipitant solution and a complexing agent solution into the reaction kettle base solution, carrying out a co-precipitation reaction, starting to introduce the amphoteric polymeric flocculant solution when the particle size of particles in the reaction kettle grows to be 2-3 microns smaller than the target particle size, then continuing the reaction, and stopping feeding until the average particle size of the particles grows to the target particle size. The polymer flocculant is utilized to form a net structure on the outer layer of the precursor particles, so that the structural strength is enhanced, and ball cracks caused by collision among the particles in the later period of the reaction of the precursor are avoided, thereby ensuring the cyclicity, stability and safety.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery positive electrode materials, in particular to a preparation method of a core-shell structure ternary positive electrode material precursor. Background technique [0002] Lithium-ion batteries have been widely used due to their good cycle performance, high capacity, low price, convenient use, safety and environmental protection. Today, with the increasing market demand for high-performance batteries such as high energy density and the continuous popularization of electric vehicles, the market demand for battery cathode materials has shown a rapid growth trend. Due to the characteristics of high energy density, relatively low cost, and excellent cycle performance, ternary cathode materials are currently the most promising materials with the greatest potential among mass-produced cathode materials. Therefore, it is imminent to improve the performance of ternary precursors. In order to g...

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Problems solved by technology

[0003] In recent years, high-nickel ternary cathode materials have become a hot spot in the industry due to their high energy density. Under the reaction conditions of pH, with the continuous growth of the particles and the continuous increase of the solid content of the reaction system, the collision between the particles will intensify, which will easily lead to the cracking of the large particles of the precursor and seriously affect the cycle performance of the battery material.

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