Lithium nickel cobalt manganese oxide gradient positive electrode material and preparation method thereof

Abstract

The invention discloses a nickel cobalt lithium manganate gradient positive electrode material and a preparation method thereof. The preparation method comprises the following steps: obtaining a nickel cobalt lithium manganate gradient positive electrode material precursor; wherein the nickel content in the nickel cobalt lithium manganate gradient positive electrode material precursor is reduced in a gradient manner from an inner core to a shell, and the cobalt content and the manganese content are increased in a gradient manner from the inner core to the shell; uniformly mixing the nickel cobalt lithium manganate gradient positive electrode material precursor and a lithium source, and performing gradient calcination to obtain the nickel cobalt lithium manganate gradient positive electrode material, wherein the gradient calcining process comprises the step of controlling the calcining temperature so that the calcining temperature gradient is reduced. According to the invention, the core and the shell are under respective optimal sintering conditions through temperature gradient calcination so as to avoid different degrees of shrinkage and gradual separation of the core and the shell in the circulation process caused by core-shell component and structure difference in the sintering process, so that the long-term circulation performance of the material is effectively improved.

Description

A kind of nickel cobalt lithium manganate gradient cathode material and preparation method thereof technical field The present invention relates to the technical field of positive electrode materials, particularly relate to a kind of gradient positive electrode material of nickel cobalt manganate and lithium manganate and its preparation preparation method. Background technique [0002] Nickel-cobalt lithium manganate ternary lithium-ion battery cathode material is widely used in new energy due to its high energy density. source automotive field. [0003] High nickel enrichment is generally employed to maximize reversible capacity. However, with the increase of nickel content, the The cation mix becomes more and more, and the cycle and thermal stability gradually decrease, which leads to a decrease in the cycle life of the battery. therefore, Some studies have proposed that by controlling the gradual decrease of nickel from the inner core to the particle surface, tha...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the above-mentioned technical deficiencies, propose a nickel-cobalt lithium manganate gradient positive electrode material and a preparation method thereof, and solve th

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