Core-shell polynary lithium ion battery anode material distributed in all-concentration gradient way and preparation method thereof

Abstract

The invention relates to a core-shell polynary lithium ion battery anode material distributed in an all-concentration gradient way and a preparation method thereof, and belongs to the field of lithium ion battery anode materials. The structural formula of the anode material is LiaNixCoyMn1-x-yO2@LibNimConMn1-m-nO2, wherein a is more than or equal to 0.9 and less than or equal to 1.2, x is more than or equal to 0.6 and less than or equal to 0.9, y is more than or equal to 0.05 and less than or equal to 0.4, b is more than or equal to 0.9 and less than or equal to 1.2, m is more than or equal to 0.2 and less than or equal to 0.7, and n is more than or equal to 0.1 and less than or equal to 0.6. The anode material is spherical or sphere-like, and is of a core-shell structure; a core part is an all-concentration gradient part being 2-10 microns in diameter; a shell part is a protective layer part being 0.5-2 microns in thickness; the concentration of the protective layer part is an all-concentration gradient end-point concentration; and from the center of a core to the surface of a shell, the nickel content decreases gradually while the cobalt content and manganese content increase gradually. The material has the advantages of low cost, high cycle performance, high safety performance, high discharge capacity and the like. Moreover, the core-shell polynary lithium ion battery anode material is simple in process flow, and easy for realizing industrial production.

Description

technical field [0001] The invention relates to a core-shell type multi-element lithium-ion battery cathode material with full concentration gradient distribution and a preparation method thereof, belonging to the field of lithium-ion battery electrode materials. Background technique [0002] In recent years, with the intensification of energy consumption and the impact of environmental pollution and other issues, people have gradually developed new and renewable energy sources such as solar energy, wind energy, geothermal energy, and nuclear energy, and chemical power sources play an important role in the field of new energy. effect. As a new generation of secondary batteries, lithium-ion batteries have the advantages of high working voltage, high specific energy, low self-discharge rate, and no memory effect. They have great application prospects in 3C batteries, electric vehicles, military defense, etc., and become power batteries and The first choice for energy storage ...

AI Technical Summary

Problems solved by technology

With the increase of doping content, the electrochemical performance of the material is improved, but when the doping content is too high, the inactive doping elements seriously affect the specific capacity of the material.

2) The method of surface coating, such as in LiNi 0.8 co 0.1 mn 0.1 o 2 The surface is coated with a layer of LiNi 0.33 co 0.33 mn 0.33 o 2 , this method can improve the safety performance of the cathode material, but there are still problems such as poor structural stability and poor cycle performance.

3) The preparation of high-nickel-based cathode materials with a concentration gradient has also become a means to overcome the shortcomings of such materials, but the concentration-gradient materials prepared by this method still have the problem of outward diffusion of nickel ions in the core, making The material becomes structurally unstable during cycling and safety performance is compromised

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