Preparation method of nickel-cobalt-manganese precursor particles

Abstract

The invention relates to a preparation method of a nickel-cobalt-manganese precursor, which specifically includes the following steps: preparing nickel-cobalt solution, nickel-manganese solution and nickel-T solution by mixing soluble nickel salt with soluble cobalt salt, soluble manganese salt and soluble salt doped with metal T respectively, wherein the concentration of the nickel-cobalt solution is higher than that of the nickel-manganese solution, and the concentration of the nickel-manganese solution is higher than that of the nickel-T solution; mixing the nickel-cobalt solution with thenickel-manganese solution and adding a complexing agent to obtain a mixed solution, and adjusting the pH value of the mixed solution to 9-11.5 by adding alkali solution; and adding the nickel-T solution to the mixed solution for reaction in an inert atmosphere to obtain nickel-cobalt-manganese precursor particles with uniform size, high purity and stable chemical performance. The prepared nickel-cobalt-manganese precursor particles show a gradient decrease in the relative content of nickel element and a gradient increase in the relative content of doped element from the core to the surface.

Description

technical field [0001] The invention relates to a method for preparing nickel-cobalt-manganese precursor particles, in particular to a method for preparing nickel-cobalt-manganese precursor particles by liquid-phase gradient doping, and belongs to the field of preparation of positive electrode materials for lithium batteries. Background technique [0002] Ternary cathode materials generally have the problem of poor structural stability. A large number of studies have proved that element doping on the surface of ternary cathode materials can effectively isolate the electrolyte from the active material without excessively reducing the electrochemical performance of the material. Avoid side reactions between the two and improve the stability of the material. [0003] At the same time, the cycle performance of the ternary cathode material can be greatly improved by element doping, thereby improving the battery life of the lithium-ion battery. [0004] Chinese patent application...

AI Technical Summary

Problems solved by technology

The doping method of this invention is backward

Moreover, simple impregnation is difficult to make the dopant elements distributed in a gradient in the precursor particles

At the same time, this method can only wrap the doping elements on the surface of the ternary precursor particles in a permeable manner, which is easy to cause the enrichment of the doping elements on the surface of the ternary precursor particles

[0006] It can be seen that the existing technology mainly adopts the method of doping elements by solid-phase method in the process of preparing lithium salts, which will cause local enrichment of doping elements, interfere with the uniformity of product particles, and reduce product stability. properties, thereby improving the material capacitance to a certain extent

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