A large-scale preparation method of a high-nickel cobalt-free precursor and positive electrode materials

Abstract

A large-scale preparation method of high-nickel and cobalt-free precursors and positive electrode materials, through the precise control of various key parameters in the co-precipitation reaction process, to achieve the regulation of the crystal plane, morphology, assembly and arrangement of primary particles , to obtain a high-nickel-cobalt-free cathode material precursor with a relatively uniform appearance. When it is used as a precursor for high-nickel-cobalt-free lithium-ion battery cathode active materials, the prepared high-nickel and cobalt-free cathode material has low residual alkali and pH It is relatively low, not easy to absorb water, has good processing performance, does not contain precious metal element cobalt, and has low cost. The cells prepared by it have high first effect and capacity, and are excellent in normal temperature cycle, high temperature cycle and high temperature storage, and through doping and coating Its thermal stability is greatly improved, its preparation process is simple and efficient, and the obtained product has high uniformity and excellent electrochemical performance, which is conducive to large-scale market promotion.

Description

technical field [0001] The invention relates to the field of energy storage materials and electrochemical technology, in particular to a large-scale preparation method of high-nickel and cobalt-free precursors and positive electrode materials. Background technique [0002] In the ternary cathode material, the main function of nickel is to participate in the oxidation-reduction reaction, which is used to increase the energy density. Surface materials with higher nickel content have higher energy density. The main role of cobalt in the ternary cathode material is to improve crystal conductivity and stabilize the structure. However, because cobalt is very expensive and lacks natural resources, it is not conducive to large-scale use. Therefore, Al, Ba, Mg, Ce, Cr, Mn, Ti, Sr, Zr, Ge, Er, W, La, Nd, Dy, Eu, Nb, Pr, Yb, Lu, Sn, Mo and other elements can be used instead of cobalt The role of elements in ternary materials. [0003] The precursor will determine the basic properties...

AI Technical Summary

Problems solved by technology

However, in this process, there are many parameters that need to be adjusted, and it is very difficult to realize the synergy of each parameter, so it is very difficult to control the growth of primary particle crystals.

[0004] While the high-nickel material has high energy density, its disadvantages are also obvious. Its structural stability and high temperature stability are poor, and the particles on the surface are prone to phase transition: layered structure → spinel structure → rock salt structure (irreversible), the surface The phase transition of the particle will extend to the interior of the particle, leading to material failure and cracking

High-nickel materials are more likely to interact with CO in the air during sintering 2 and H 2 O reacts to form Li 2 CO 3 And LiOH, in this case the material is more likely to absorb water, the pH is higher, and the processing performance is deteriorated; and too much Li 2 CO 3 Can cause flatulence, affect high temperature cycling and high temperature storage

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