Cobalt-free layered cathode material and preparation method thereof and lithium ion battery

Abstract

The invention provides a cobalt-free layered cathode material and a preparation method thereof and a lithium ion battery. The cobalt-free layered cathode material is of a core-shell structure, a material forming a shell of the core-shell structure comprises titanium nitride, and a material forming the inner core of the core-shell structure does not comprise cobalt and is of a single crystal structure. According to the cobalt-free layered cathode material provided by the invention, high-conductivity titanium nitride is coated on the surface of the cobalt-free inner core, so that the rate capability of the cathode material can be improved while the price cost of the cathode material is reduced, and the rate capability of the cobalt-free cathode material is better.

Description

technical field [0001] The invention relates to the technical field of cathode materials for lithium-ion batteries. Specifically, the invention relates to a cobalt-free layered cathode material, a preparation method thereof, and a lithium-ion battery. Background technique [0002] At present, ternary cathode materials are more and more widely used in lithium-ion power batteries. Traditional ternary cathode materials generally contain cobalt, and the price of cobalt is the highest among the three elements, which will cause the price of ternary cathode materials to be higher than that of LiFePO 4 , LiMn 2 o 4 and other cathode materials are significantly higher. Therefore, ternary cathode materials are developing towards low-cobalt or even cobalt-free. [0003] Although the cobalt-free layered cathode material has higher capacity and lower cost, however, the cobalt-free conversion reduces the conductivity of the cathode material, which in turn affects the rate performance ...

AI Technical Summary

Problems solved by technology

[0005] The inventors of the present invention aimed at the technical problems of poor conductivity and poor rate performance of cobalt-free cathode materials, and provided a cathode material with high-conductivity titanium nitride on the surface, which can not only improve the surface conductivity of cobalt-free materials , and at the same time reduce the surface impedance of cobalt-free materials, thereby improving the electrical properties of cobalt-free materials such as cycle and rate

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