Positive electrode material for lithium battery, preparation method and application thereof

Abstract

The invention provides a cathode material for a lithium battery, a preparation method and application thereof. The anode material for a lithium battery according to the present invention includes a lithium metal composite oxide having a layered structure and a boron coating layer formed on the surface of the lithium metal composite oxide, wherein the lithium metal composite oxide includes Li, Ni and doping element M1, said doping element M1 is at least one selected from Zr, Mg, Al, Ni, Mn, Zn, Fe, Cr, Mo and W, said Ni and said doping element The molar ratio of the sum of M1 to the Li is less than 1, and the boron coating layer includes boron and / or boride. The positive electrode material for the lithium battery has good structural stability, stable electrochemical performance, and is not easy to react with the electrolyte.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a positive electrode material for lithium batteries and a preparation method and application thereof. Background technique [0002] At present, the new energy industry is developing rapidly. As an important part of the new energy industry, new energy vehicles have put forward higher requirements for the stability and safety of batteries. As the core of new energy vehicles, power batteries will directly determine the performance of new energy vehicles. In order to meet the needs of new energy vehicles for mileage and cost performance, researchers generally use high-nickel cathode materials to replace traditional LiCoO 2 Material. Lithium-nickel oxides are not only cheaper than cobalt oxides, but also have a higher discharge capacity when charged at 4.3V, and the reversible capacity of doped lithium-nickel oxides exceeds that of LiCoO 2 The capacity (165mAh / g) is about ...

AI Technical Summary

Problems solved by technology

Lithium-nickel oxides are not only cheaper than cobalt oxides, but also have a higher discharge capacity when charged at 4.3V, and the reversible capacity of doped lithium-nickel oxides exceeds that of LiCoO 2 The capacity (165mAh / g) is about 200mAh / g, so the lithium nickel-based positive electrode active material not only has a slightly lower discharge voltage and volume density, but also has improved energy density, and is used in high-capacity batteries; but lithium nickel The biggest problem of the positive electrode active material is the Li remaining on the surface during synthesis. 2 CO 3 and the presence of lithium impurities such as LiOH, the lithium impurities remaining on the surface will interact with the CO in the air 2 or H 2 O reacts to form Li 2 CO 3 , such that Li 2 CO 3 Not only will it cause the formation of initial irreversible capacity and hinder the movement of lithium ions on the surface, but also become the main cause of gas generation due to the decomposition reaction in the electrochemical reaction. The existence of these residual alkalis will affect the battery cycle performance and safety performance

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