A treatment process to improve the stability and conductivity of high-nickel cathode materials

A cathode material and processing technology technology, applied in the field of lithium-ion battery cathode materials, can solve the problems of high requirements for sintering conditions, materials are sensitive to air, and viscosity of slurry increases, so as to improve rate performance, improve consistency and stability, The effect of increasing electrical conductivity

Active Publication Date: 2021-07-23
ZHEJIANG UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, high-nickel cathode materials still have the following disadvantages: the material has high requirements for sintering conditions, and lithium-nickel mixing is prone to occur during the sintering process; the surface of the sintered material is highly alkaline, which makes the material sensitive to air The reaction with carbon dioxide will cause the material to deteriorate from the outside to the inside. At the same time, too strong alkalinity will increase the viscosity of the prepared slurry, resulting in difficulty in coating; the poor conductivity of the material will lead to poor rate performance, etc.

Method used

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  • A treatment process to improve the stability and conductivity of high-nickel cathode materials
  • A treatment process to improve the stability and conductivity of high-nickel cathode materials
  • A treatment process to improve the stability and conductivity of high-nickel cathode materials

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] A treatment process to improve the stability and conductivity of high-nickel cathode materials,

[0034] Based on the high-temperature sintering furnace 6, a porcelain boat 1 is arranged inside the high-temperature sintering furnace 6, and a corundum tube 8 is provided on the outer cover of the porcelain boat 1, and the air inlet of the corundum tube 8 is provided with a carbon dioxide channel with a valve, oxygen channel and ozone channel, the ozone channel is also provided with an ozone generator 2, and the gas outlet of the corundum tube 8 is provided with an exhaust absorption device 7,

[0035] Described processing technology comprises the steps:

[0036] S1, the high-nickel cathode material precursor Ni 0.8 co 0.1 mn 0.1 (OH) 2 and lithium salt LiOH·H 2 O is mixed uniformly according to the molar ratio of 1:1.05 according to the molar ratio, the mixture homogeneously mixed is placed in the porcelain boat 1, then the porcelain boat 1 is put into the high-tempe...

Embodiment 2~5

[0047] On the basis of Example 1, only the carbon dioxide plasma treatment time was changed, and the carbon dioxide plasma treatment time in Examples 6-9 were 10 min, 20 min, 30 min, and 50 min, respectively. The cycle performance of button batteries assembled with high-nickel cathode materials obtained under different conditions is shown in Table 1 (charge and discharge current density is 100mA / g), and the influence of carbon dioxide plasma treatment time on battery cycle stability was discussed.

[0048] Table 1: Effect of carbon dioxide plasma treatment time on battery cycle stability

[0049]

[0050] It can be seen from Examples 2-5 that the carbon dioxide plasma treatment can enhance the charge storage performance and cycle performance of the material, but if the treatment time is too long, the material will be damaged and the cycle stability and capacity will be reduced.

Embodiment 6~8

[0052] On the basis of Example 1, the carbon dioxide annealing time was changed, and the carbon dioxide annealing time of Examples 6-8 were 20 min, 40 min, and 80 min, respectively. The cycle performance of button batteries assembled with high-nickel cathode materials obtained under different conditions is shown in Table 2 (charge and discharge current density is 100mA / g), and the influence of carbon dioxide annealing time on battery cycle stability was discussed.

[0053] Table 2: Effect of carbon dioxide annealing time on battery cycle stability

[0054]

[0055] It can be seen from Examples 6-8 that although the carbon dioxide annealing treatment will lose part of the initial discharge capacity, it can improve the cycle stability of the material.

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Abstract

The invention provides a treatment process for improving the stability and conductivity of a high-nickel positive electrode material, and carbon dioxide annealing treatment and carbon dioxide plasma treatment are respectively performed on the high-nickel positive electrode material obtained by sintering in an ozone atmosphere. The method can not only shorten the sintering time of materials, increase production capacity, reduce the amount of gas, and reduce costs, but also can reduce the degree of lithium-nickel mixing of high-nickel cathode materials, improve the consistency and stability of materials, and prolong the service life of batteries; After the sintering, carbon dioxide gas is continuously introduced for annealing treatment, which can react with the residual lithium hydroxide on the surface of the high-nickel cathode material, reduce the residual alkali content on the surface of the material, reduce the sensitivity of the material to air, prolong the storage time of the material, and improve the The processing performance of the material; finally, carbon dioxide plasma treatment is performed to coat a carbon layer on the surface of the material to increase the electrical conductivity of the material, thereby improving the rate performance of the material.

Description

technical field [0001] The invention relates to a treatment process for improving the stability and conductivity of high-nickel positive electrode materials, and belongs to the technical field of lithium ion battery positive electrode materials. Background technique [0002] With the development of new energy vehicles and lithium-ion power batteries, high-nickel cathode materials have become a research hotspot because of their high reversible charge-discharge capacity. However, high-nickel cathode materials still have the following disadvantages: the material has high requirements for sintering conditions, and lithium-nickel mixing is prone to occur during the sintering process; the surface of the sintered material is highly alkaline, which makes the material sensitive to air The reaction with carbon dioxide will cause the material to deteriorate from the outside to the inside. At the same time, too strong alkalinity will increase the viscosity of the prepared slurry, result...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/485H01M4/505H01M4/525H01M4/62H01M10/0525
CPCH01M4/366H01M4/485H01M4/505H01M4/525H01M4/625H01M10/0525Y02E60/10
Inventor 张文魁陈安琪王坤夏阳吴海军钱志挺毛秦钟黄辉张俊甘永平梁初
Owner ZHEJIANG UNIV OF TECH
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