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A kind of synthesis method of positive electrode material with high interfacial stability

A technology of positive electrode material and synthesis method, which is applied in the direction of battery electrodes, structural parts, electrical components, etc., can solve the problems of destroying crystal structure stability, poor slurry stability, easy-absorbing electrolyte, etc., to promote the diffusion of lithium ions and crystal growth, reduce the cladding temperature, and improve the effect of the reaction atmosphere

Active Publication Date: 2020-04-17
SOUNDON NEW ENERGY TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Li on the surface of the material 2 CO 3 Or LiOH and other combined forms are attached to the surface of the particles, which are very easy to absorb water and have side reactions with the electrolyte, resulting in poor slurry stability, attenuation of cycle performance or even diving, and deterioration of safety performance
The existing technology generally uses water washing, coating and heat treatment at a higher temperature. The problem is that when the free Li on the surface is reduced, the high temperature heat treatment will cause lithium ions to escape from the crystal structure and destroy the stability of the crystal structure.

Method used

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  • A kind of synthesis method of positive electrode material with high interfacial stability
  • A kind of synthesis method of positive electrode material with high interfacial stability
  • A kind of synthesis method of positive electrode material with high interfacial stability

Examples

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Embodiment 1

[0020] Weigh Li according to molar ratio Li:(Ni+Mn+Co)=1.05:1 2 CO 3 、Ni 0.6 co 0.2 mn 0.2 (OH) 2 , and weigh 1wt% PMMA at the same time, put the three in a high-speed mixer and mix them evenly, then place them in an air atmosphere furnace and sinter at 900°C for 12h to obtain a base material: Li x Ni 0.6 co 0.2 mn 0.2 o 2 . A small amount of sintered finished product was taken for testing, and the measured free Li content was 700ppm. Weigh a certain amount of Li x Ni 0.6 co 0.2 mn 0.2 o 2 , calculate and take by weighing the aluminum nitrate that is equal to the free Li content contained in the matrix, first disperse the aluminum nitrate in deionized water, after stirring for 90min, add 15wt% alanine and Li x Ni 0.6 co 0.2 mn 0.2 o 2 The matrix was stirred for 30 minutes, and the obtained paste material was dried and then self-propagating sintering was initiated at 300°C for 6 hours to obtain the surface-coated α-LiAlO 2 LiNi 0.6 co 0.2 mn 0.2 o 2 . T...

Embodiment 2

[0024] figure 1 The first charge-discharge curve obtained from the test after the material of this embodiment is assembled into a button battery; figure 2 It is the scanning electron microscope picture of the material of this example. Weigh LiOH·H according to the molar ratio Li:(Ni+Mn+Co)=1.045:1 2 O, Ni 0.8 co 0.1 mn 0.1 (OH) 2, 2wt% of PEG10000 was placed in a high-speed mixer and mixed evenly, then placed in an oxygen atmosphere furnace and sintered at 750 ° C for 12 hours to obtain a matrix material: Li x Ni 0.8 co 0.1 mn 0.1 o 2 ; A small amount of sintered finished product was taken for testing, and the measured free Li content was 1200ppm. Weigh a certain amount of Li x Ni 0.8 co 0.1 mn 0.1 o 2 , calculate and weigh the aluminum isopropoxide equivalent to the free Li content contained in the matrix, first disperse the aluminum isopropoxide in absolute ethanol, stir for 120min, then add 10wt% starch and Li x Ni 0.8 co 0.1 mn 0.1 o 2 The matrix was s...

Embodiment 3

[0026] image 3 It is the high-temperature cycle performance curve obtained from the test after the product of this example is assembled into a square battery, and LiOH·H 2 O, Ni 0.85 co 0.1 Al 0.05 (OH) 2 , 6wt% PVP is placed in a high-speed mixer and mixed evenly, then placed in an oxygen atmosphere furnace for sintering at 710°C for 10h to obtain a base material: Li x Ni 0.85 co 0.1 Al 0.05 o 2 ; A small amount of sintered finished product was taken for testing, and the measured free Li content was 1500ppm. Weigh a certain amount of Li x Ni 0.85 co 0.1 Al 0.05 o 2 , calculate and weigh the aluminum isopropoxide equivalent to the free Li content contained in the matrix, first disperse the aluminum isopropoxide in absolute ethanol, stir for 150min, then add 10wt% starch and Li x Ni 0.85 co 0.1 Al 0.05 o 2 matrix, and continue to stir for 40min, after drying the obtained paste material, initiate self-propagating sintering at 370°C for 5h, and obtain the surfa...

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Abstract

Disclosed is a high-interface stability positive-electrode material synthesis method. The method includes: firstly, synthesizing a lithium-ion battery positive-electrode material matrix through high-temperature solid state reaction; then performing low-temperature heat treatment combining with a liquid phase coating and self-propagation method to obtain the target product. The target product comprises a body material and a coating layer, the structural formula of the body can be indicated as LixMo2, 0.9 is smaller than or equal to x which is smaller than or equal to 1.2, wherein M equals to one or multiple kinds of Co, Ni, Mn and Al; the coating layer is alpha-LiAlO2. Surface ionization Li on the matrix is firstly detected, and then an Al source of equivalence ratio and organic matters needed for self-propagation sintering are added, the coating of the surface is synthesized under low-temperature self-propagation sintering, the surface ionization Li can be reduced to the greatest extent, removal of the Li form the interior of the matrix is avoided, the coating resistant to electrolytic corrosion is formed in the surface of the matrix, and the obtained material is high in interface stability, less prone to water absorption, good in processing performance, and excellent in high-temperature performance and safety performance.

Description

technical field [0001] The invention belongs to positive electrode materials of lithium ion batteries, in particular to a method for synthesizing positive electrode materials with high interface stability. Background technique [0002] Lithium-ion batteries include four main components: positive electrode materials, negative electrode materials, separators, and electrolytes. Among them, positive electrode materials are the key to determining the performance and cost of lithium-ion batteries. At present, the mainstream positive electrode materials on the market include lithium cobaltate, lithium manganate, lithium iron phosphate, and multi-component materials with nickel as the main component. The synthesis method is generally high-temperature sintering method. It is mixed with the precursor of the material, and then sintered at high temperature, so that lithium ions are diffused and infiltrated into the precursor at high temperature, forming a lithium metal oxide with a cert...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/1391H01M4/62
CPCH01M4/1391H01M4/62Y02E60/10
Inventor 唐泽勋陈敏周宇商士波
Owner SOUNDON NEW ENERGY TECH CO LTD