A precursor of nickel-cobalt lithium manganese oxide material and its preparation method, and a lithium-ion battery prepared from the precursor

Abstract

The invention relates to a lithium nickel cobalt manganese oxide material precursor and a preparation method thereof and a lithium-ion battery prepared from the precursor. The lithium nickel cobalt manganese oxide material precursor is in a spherical form, primary particles are in the shape of emissive strips and the chemical formula is Ni(1-x-y)Co<x>Mn<y>(OH)<2>, wherein x is smaller than 0.2 and greater than 0 and y is smaller than 0.2 and greater than 0, the tap density is 1.6-1.9g / cm<3>, the median particle size D50 is 6-18 microns and the average pore size is 14-18nm. The preparation method of the lithium nickel cobalt manganese oxide material precursor is improved on the basis of a traditional one-step method, and the precursor prepared through the method has the characteristics of a precursor product under a single anti-oxidation condition and also has the characteristics of a precursor product under a single oxidation condition; and a ternary positive electrode material prepared from the precursor has the advantages of high capacity and high cycle performance, and also has the advantages of high compaction density, good heat stability and low self-discharge rate.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery materials, and in particular relates to a nickel cobalt lithium manganese oxide material precursor, a preparation method thereof, and a lithium ion battery prepared from the precursor. Background technique [0002] As a new type of green secondary battery, lithium-ion battery has the advantages of large specific capacity, small self-discharge, light weight, and no memory effect. It has been widely used in various mobile electronic products (such as mobile phones, cameras, notebook computers, etc.) ), artificial satellites, aerospace and other fields, and breakthroughs have also been made in the field of electric vehicles. In order to meet the growing needs of these application fields, the demand for lithium-ion secondary batteries with larger capacity, higher rate performance, and longer cycle life is increasing. Therefore, the specific capacity and rate performance of lithium-ion batt...

AI Technical Summary

Problems solved by technology

The positive electrode material sintered by the first precursor has a high capacity but poor cycle performance. This is due to the low porosity caused by the dense packing of primary particles inside the precursor particles, which will hinder the diffusion of lithium ions to a certain extent; As the charge and discharge continue, the situation that hinders the diffusion of lithium ions is more serious, resulting in a significant decline in the capacity in the later period.

The positive electrode material sintered from the second precursor has good cycle performance but low capacity. This is because the internal particles of the precursor are too loose, the porosity is too high, and the diffusion path of lithium ions is too long, resulting in low energy density of the material.

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