Method for preparing lithium nickel cobalt manganese oxide ternary cathode material in liquid-phase sugar coating and spray drying manners

Abstract

The invention discloses a method for preparing a lithium nickel cobalt manganese oxide ternary cathode material in liquid-phase sugar coating and spray drying manners. The method comprises the steps of firstly mixing sulphate liquids of Ni, Co and Mn, performing a coprecipitation reaction under an alkaline condition to prepare a ternary composite precursor (NixCoyMnz)(OH)2, filtering, washing, drying, adding the ternary composite precursor, a soluble metal lithium compound, a rare earth compound to a sugar-dissolved solvent, uniformly mixing, and spray drying to obtain a sugar-coated rare-earth-element-doped ternary precursor, finally performing high-temperature calcination to obtain a rare-earth-element-doped ternary material LiNixCoyMnzRnO2, wherein R is a doped rare earth element, the sum of x, y and z is equal to 1, and n is not less than 0.002 and is not greater than 0.1. According to the method for preparing the lithium nickel cobalt manganese oxide ternary cathode material in the liquid-phase sugar coating and spray drying manners, sugar coating is utilized, so that the dissipation of pungent smell is reduced in a spray drying process; the prepared stoichiometric-ratio ternary material has the advantages that the secondary particle dispersity is good, the size is uniform, the infiltration of electrolyte is facilitated, the diffusion rate of lithium ions is increased basically, and the impedance of the lithium ions during diffusion is reduced, so that the electrical property of a material is improved, and the stable production is convenient.

Description

technical field [0001] The invention relates to a method for preparing nickel-cobalt-lithium-manganese-oxide ternary cathode material by spraying and drying liquid-phase sugar coating. Background technique [0002] Lithium-ion batteries, as a new generation of energy storage batteries, are developing rapidly in the fields of various consumer electronics products, and have shown potential application value in the fields of electric vehicles, electric vehicles and aerospace. The performance and cost of lithium-ion batteries depend largely on the cathode material. At present, the specific capacity of the negative electrode material of lithium ion battery is twice that of the positive electrode material, so the low specific capacity of the positive electrode material has become a bottleneck restricting the development of lithium ion battery. important practical significance. [0003] Because the ternary nickel-cobalt lithium manganese oxide material inherits the advantages of ...

AI Technical Summary

Problems solved by technology

One: the use of dry or wet mixing of lithium leads to uneven mixing of the precursor and lithium, and the particle size is not easy to control, making it difficult to control the stability of the final product; the lithium dinickel cobalt manganese oxide is produced at a high temperature above 850 °C After a certain period of heat preservation and calcination synthesis, the crystal grains will grow rapidly during the calcination process, and the particle size is difficult to control, resulting in a negative impact on the initial discharge capacity and cycle performance of the material; third: the radius of lithium ions is similar to that of nickel ions. During the discharge process, nickel ions easily occupy the position of lithium ions and the crystal structure collapses

The collapse of the crystal structure not only destroys the Li + The transmission channel, and the battery is coming out of the Li 2 After O, the ion rearrangement is hindered, and the octahedral vacancies are occupied. After discharge, there are not enough positions for lithium ions to intercalate, resulting in lithium precipitation, which seriously affects the performance of electrical properties.

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