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A kind of positive electrode slurry of lithium ion battery and preparation method thereof

A lithium-ion battery and positive electrode slurry technology, which is applied to battery electrodes, secondary batteries, circuits, etc., can solve the problems of dry cracks, binder migration, and large environmental hazards, so as to improve production efficiency, reduce usage, The effect of reducing energy consumption

Active Publication Date: 2020-09-15
CHINA AVIATION LITHIUM BATTERY LUOYANG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

During the coating drying process of traditional positive electrode slurry, due to the low solid content, a large amount of solvent in the slurry must be removed by the heat energy provided by the oven, which has the following disadvantages: high energy consumption, low coating efficiency, and environmental hazards Big
However, this cannot fundamentally solve the defects existing in the drying of traditional slurries, and it is easy to cause problems such as dry cracking of the pole pieces. Excessive drying speed may also cause the binder to migrate to the surface of the coating, and the gap between the active material and the current collector Easy to peel

Method used

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  • A kind of positive electrode slurry of lithium ion battery and preparation method thereof

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Experimental program
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Embodiment 1

[0035] The lithium ion battery cathode slurry in this embodiment is a mixture of the cathode material and N-methylpyrrolidone, the cathode material is composed of lithium iron phosphate, binder and conductive agent, the lithium iron phosphate, binder and The mass percentages of the conductive agent are respectively: 95%, 3%, and 2%. The binder is composed of a mixture of homopolymerized PVDF and modified PVDF with a mass ratio of 1:1. The modified PVDF is homopolymerized PVDF with a polar functional group -C-O-C-ester group. The homopolymerized PVDF The weight average molecular weight is 200,000, the weight average molecular weight of the modified PVDF is 800,000, and the conductive agent is carbon nanotube slurry containing 1% polyvinylpyrrolidone.

[0036] The preparation method of the positive electrode slurry of the lithium ion battery of the present embodiment comprises the following steps: (1), the mixed binder 95g that the mass ratio is 1:1 composition of homopolymeriza...

Embodiment 2

[0038] The positive electrode slurry of this embodiment differs from that of Example 1 in that the mass percentages of lithium iron phosphate, binder and conductive agent in the positive electrode material are: 90%, 4%, 6%, and the homopolymer PVDF The weight-average molecular weight of the modified PVDF is 1.2 million, and the weight-average molecular weight of the modified PVDF is 200,000, and the others remain unchanged.

[0039] The preparation method of the lithium ion battery positive electrode slurry in this embodiment is the same as that in Embodiment 1.

Embodiment 3

[0041] The lithium ion battery positive electrode slurry in this embodiment is a mixture of positive electrode material and N-methylpyrrolidone, the positive electrode material is composed of lithium iron phosphate, binder and conductive agent tube, the lithium iron phosphate, binder The mass percentages of the conductive agent and the conductive agent are respectively: 94%, 4%, and 2%. The binder is composed of a mixture of homopolymerized PVDF and modified PVDF with a mass ratio of 4:1. The modified PVDF is homopolymerized PVDF with polar functional groups: carbonyl and -C-O-C-ester groups. The The weight-average molecular weight of the homopolymerized PVDF is 200,000, and the weight-average molecular weight of the modified PVDF is 1.2 million. The conductive agent is carbon nanotube slurry containing 5% polyvinylpyrrolidone.

[0042]The preparation method of the positive electrode slurry of the lithium ion battery of the present embodiment comprises the following steps: (1...

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Abstract

The invention relates to lithium ion battery cathode slurry and a method of preparing same and belongs to the technical field of lithium ion batteries. The lithium ion battery cathode slurry includesa cathode material and an organic solvent, wherein the cathode material includes: a cathode active substance, a binder and a conductive agent. The binder is a mixture of polyvinylidene fluoride (PVDF)and modified PVDF according to mass ratio of 1-4:1. Solid content of the cathode slurry is 60-70%. The invention also discloses a preparation method of the cathode slurry. In the invention, the solidcontent of the cathode slurry is increased by about 15%, so that the cathode slurry has good stability and is free of jelly, granules and the like. A cathode plate can be dried quickly during manufacturing, thus reducing energy consumption. Coating speed of the cathode slurry is increased by about 80% than that of common cathode slurry, thus improving production efficiency. The usage amount of N-methylpyrrolidone is reduced in the slurry, so that the product is more environment-friendly.

Description

technical field [0001] The invention relates to a lithium ion battery cathode slurry and a preparation method thereof, belonging to the technical field of lithium ion batteries. Background technique [0002] Lithium-ion batteries have the advantages of high specific energy, long cycle life, stable working voltage, small self-discharge, high safety performance, low environmental pollution and no memory effect, and are expected to be widely used in electric vehicles and clean electric energy such as solar energy and wind energy storage. Since Japanese companies successfully commercialized lithium-ion batteries in the early 1990s, lithium-ion batteries have received widespread attention and research. [0003] In industrial production, the drying process after pole piece coating is an important process in the electrode coating process. The traditional drying process is electric heating and blowing air through the blower, and the coating is dried by circulating hot air. During...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/62H01M10/0525
CPCH01M4/623H01M10/0525Y02E60/10
Inventor 吉星王志敏于华章潘芳芳郭建峰
Owner CHINA AVIATION LITHIUM BATTERY LUOYANG