Cation-doped gradient high-nickel multi-material precursor and preparation method and application thereof

Abstract

The invention discloses a cation-doped gradient high-nickel multi-material precursor and a preparation method and application thereof. An automatic program control system is combined with a special-designed U-shaped reactor; material component ratio and a preparation process are controlled; therefore, a high-nickel multi-material precursor with nano-spherical microstructure is prepared in controllable manner. The precursor herein comprises a core and a multilayer shell portion attached to the same. A cathode material prepared with the precursor herein has continuously gradient changes in composition and structure; no evident boundary occurs in the cathode material. A core portion of the cathode material has high nickel content, so that the specific capacity is very high; a shell portion has more stable structure and better electrochemical properties; doping components help improve conductivity and battery rate performance; therefore, a gradient material with excellent comprehensive performance is attained. The preparation method herein is highly operable, easy to control and suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the field of preparation of cathode materials for lithium-ion secondary batteries, and in particular relates to a gradient high-nickel multi-component material precursor and a preparation method and application thereof. Background technique [0002] As a new type of green energy, lithium-ion secondary batteries (hereinafter referred to as "lithium-ion batteries") have been widely used in consumer electronics, electric vehicles, and various energy storage power systems. The rapid development of the industry has led to increasing requirements for lithium-ion batteries: increasing energy density and power density, extending service life, improving safety performance and reducing costs. The performance of lithium-ion batteries is largely determined by the cathode material. Therefore, the development of high-performance, high-safety, and low-cost cathode materials is an opportunity and a huge challenge for the further development of...

AI Technical Summary

Problems solved by technology

[0004] Although the high-nickel multi-component material has a high specific capacity, its disadvantages are also more prominent: (1) due to the high nickel content, the high-nickel multi-component material has poor thermal stability and low safety performance; (2) due to the high nickel content 2+ Radius and Li + similar radius, Ni 2+ with Li + Occupy each other, resulting in the occurrence of cation mixing, and the disordered state of this structure directly leads to poor rate performance and cycle performance of multi-component materials.

(3) The surface pH of high-nickel multi-component materials is relatively high, and it is easy to absorb water. During the processing, there is a high requirement for the humidity of the environment, which greatly increases the difficulty of cell process processing and equipment investment costs.

However, due to the complex synthesis process of gradient structure high-nickel multi-component materials, low efficiency, and high requirements for supporting equipment, it has seriously hindered its industrialization process.

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