Large scale preparation method of high-nickel cobalt-free precursor and cathode material

Abstract

The invention discloses a large scale preparation method of a high-nickel cobalt-free precursor and a cathode material. During the co-precipitation reaction process, the key parameters are precisely controlled, thus the crystal face, morphology, and assembly arrangement mode of primary particles are regulated and controlled to obtain the high-nickel cobalt-free cathode material precursor with uniform morphology, the precursor can be used to prepare the high-nickel cobalt-free lithium battery cathode active material, which has the advantages of low residual alkali, low pH value, water absorption resistance, and good processing performance, moreover, the cathode material does not contain any precious metal and is cheap; the prepared lithium battery has the advantages of high cell primary effect, high capacity, excellent normal temperature cycle performance, good high temperature cycle performance, and excellent high temperature storage performance; moreover, the thermal stability is greatly improved through doping and coating; the preparation process is simple and efficient; and the obtained product is highly uniform, has excellent electrochemical properties, and has a wide market prospect.

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 high-nickel materials have high energy density, their disadvantages are also obvious. Their 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), 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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