Preparation technology capable of improving cycle performance and electrical conductivity of high-nickel positive electrode material

A cathode material and preparation technology, applied in the field of cathode materials for lithium-ion batteries, can solve problems such as poor battery rate performance, decreased cycle performance, and reduced material capacity, and achieve shortened sintering time, reduced gas consumption, and reduced residual alkali content Effect

Active Publication Date: 2019-10-18
ZHEJIANG UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are still many problems in high-nickel cathode materials, such as: high-nickel materials have poor conductivity, resulting in poor battery rate performance; high-nickel cathode materials are prone to lithium-nickel mixing during sintering, resulting in reduced capacity and The cycle performance is reduced. In order to reduce the degree of lithium-nickel mixing, it is necessary to fully oxidize the divalent nickel ions into trivalent nickel ions, which puts forward high requirements on the sintering conditions.

Method used

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  • Preparation technology capable of improving cycle performance and electrical conductivity of high-nickel positive electrode material
  • Preparation technology capable of improving cycle performance and electrical conductivity of high-nickel positive electrode material
  • Preparation technology capable of improving cycle performance and electrical conductivity of high-nickel positive electrode material

Examples

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Comparison scheme
Effect test

Embodiment 1

[0033] A preparation process for improving the cycle performance and conductivity of high-nickel cathode materials,

[0034] Based on the high-temperature sintering furnace 5, a porcelain boat 1 is provided inside the high-temperature sintering furnace 5, and a corundum tube 7 is provided on the outer cover of the porcelain boat 1, and an ozone channel with a valve and an oxygen gas channel are provided in parallel at the air inlet of the corundum tube 7. channel, the ozone channel is also provided with an ozone generator 2, and the gas outlet of the corundum tube 7 is provided with an exhaust absorption device 6,

[0035] Described preparation process 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 evenly according to the molar ratio of 1:1.05 according to the molar ratio, and the evenly mixed mixture is placed in the porcelain boat 1, then the porcelain boat 1 is put into the h...

Embodiment 2~5

[0046] On the basis of Example 1, in Examples 2 to 5, the number of times that the ozone gas is introduced is changed to 1 time, 2 times, 4 times, and 5 times respectively, without changing the time of each time the ozone gas is introduced, that is, a total of ozone gas is introduced. Gas 20min, 40min, 80min, 100min. The cycle performance of the button battery assembled with the high-nickel cathode material obtained under different conditions is shown in Table 1 below (the charge and discharge current density is 100mA / g), and the influence of the time of ozone introduction on the battery cycle performance is discussed.

[0047] Table 1: The influence of the time of passing ozone on the cycle performance of the battery

[0048]

[0049] It can be seen from Examples 2-5 that sintering with ozone for a period of time can improve the cycle performance of the material, and the optimum time for sintering is about 80 minutes.

Embodiment 6~9

[0051] 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 2 (charge and discharge current density is 100mA / g), and the influence of carbon dioxide plasma treatment time on battery cycle stability was discussed.

[0052] Table 2: Effect of carbon dioxide plasma treatment time on battery cycle stability

[0053]

[0054] It can be seen from Examples 6-9 that the carbon dioxide plasma treatment can improve the initial discharge capacity and cycle performance, but if the treatment time is too long, the material will be damaged, and the cycle stability and capacity will decrease.

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Abstract

The invention provides a preparation technology capable of improving the cycle performance and the electrical conductivity of a high-nickel positive electrode material. The preparation technology comprises the steps of mixing a high-nickel positive electrode material precursor with a lithium salt evenly at a certain ratio; sintering in ozone-containing oxygen or air atmosphere; and carrying out carbon dioxide plasma processing after sintering is ended. According to the method, the sintering time of the material ca be shortened, the productivity is improved, the amount of a gas is reduced, thecost is reduced, the lithium-nickel mixed discharge degree of the high-nickel positive electrode material is reduced and the consistency and the stability of the material are improved; carbon dioxideplasma processing is carried out after sintering is ended, so that the residual alkali content on the surface can be reduced; and a carbon film can be formed on the surface, so that the electrical conductivity and the rate capability of the material are improved.

Description

technical field [0001] The invention relates to a preparation process for improving the cycle performance and conductivity of high-nickel positive electrode materials, and belongs to the technical field of lithium ion battery positive electrode materials. Background technique [0002] High-nickel cathode materials have higher reversible discharge capacity and higher average working voltage, so they have higher energy density, and are expected to become the cathode materials for next-generation lithium-ion power batteries. However, there are still many problems in high-nickel cathode materials, such as: high-nickel materials have poor conductivity, resulting in poor battery rate performance; high-nickel cathode materials are prone to lithium-nickel mixing during sintering, resulting in reduced capacity and The cycle performance is reduced. In order to reduce the degree of lithium-nickel mixing, it is necessary to fully oxidize the divalent nickel ions into trivalent nickel io...

Claims

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Application Information

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IPC IPC(8): H01M4/36H01M4/485H01M4/505H01M4/525H01M4/62H01M10/0525
CPCH01M4/362H01M4/485H01M4/505H01M4/525H01M4/625H01M10/0525H01M2004/028Y02E60/10
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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