Nickel, cobalt, lithium manganate core-shell material gel and preparation method therefor

Abstract

The invention provides nickel, cobalt, lithium manganate core-shell material gel and a preparation method therefor. A nickel, cobalt, lithium manganate positive electrode material adopts a spherical-like core-shell structure doped with a little amount of metal elements, wherein the content of nickel in an inner layer is high, and the content of nickel in the outer layer is relatively low; a lithium source solution and a chelating agent solution are dropwise added to a metal salt solution I in sequence to form gel I; the gel is subjected to water bath heating to obtain a gelation precursor I; next, the gelation precursor is subjected to smashing and spheroidizing technologies to prepare a spheroidized precursor I; the lithium source solution and the chelating agent solution are dropwise added to a metal salt solution II in sequence to be subjected to gel treatment, sol treatment and smashing to obtain a precursor II; next, by virtue of the spheroidizing technology and by taking the spheroidized precursor I as the core, the precursor II is subjected to surface coating to obtain the final spherical core-shell precursor; and the spherical core-shell precursor is subjected to high-temperature sintering in an oxygen atmosphere to obtain the doped core-shell material. By virtue of the gel method, the main elements and the doped elements can be dispersed uniformly; and meanwhile, by virtue of coating of the outer layer low-nickel element, the tolerance of the material in the air can be improved, thereby greatly improving the rate, cycling and safety performance of the ternary material.

Description

technical field [0001] The patent of the present invention relates to the technical field of lithium batteries, in particular to a nickel, cobalt, lithium manganate core-shell material gel and a preparation method thereof. technical background [0002] At present, researchers generally use high-temperature solid-phase method and co-precipitation method to prepare ternary materials. The high-temperature solid-phase method is a traditional method often used in the preparation of positive electrode materials. A certain proportion of raw materials are mixed and then mechanically ground and high-temperature roasted to prepare the target product. Although the solid-phase method is simple to operate and easy to produce industrially, it requires a high temperature and a long time for calcination, which is a waste of energy, and the prepared material has poor mixing uniformity, and it is difficult to control the particle size and shape. The co-precipitation method is mainly to co-pr...

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Problems solved by technology

[0004] The object of the present invention is to aim at the above-mentioned shortcomings existing in the prior art, to provide a kind of nickel, cobalt, lithium manganate core-shell material gel preparation method, the core-shell ternary material after the doping prepared by the method of the present invention, and It can overcome the problems of unstable structure and poor environmental tolerance of high-nickel materials, thereby improving the cycle, rate and safety performance of materials

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