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Lithium ion battery pole piece and diaphragm compounding method and lithium ion battery

A lithium-ion battery and diaphragm technology, which is applied in the composite field of pole pieces and diaphragms, can solve problems such as incomplete safety, poor compounding of pole pieces and diaphragms, etc., so as to solve the problem of loose batteries, avoid consistency deterioration, and reduce The effect of short circuit rate

Pending Publication Date: 2021-07-16
深圳市懋略技术研究有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In order to solve the problems in the prior art that the pole piece and the diaphragm are not tightly combined and the safety or incompleteness in the lithium supplementation process, the invention provides a method for the pole piece and the diaphragm to be tightly combined, and the lithium supplementation is safe and thorough

Method used

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  • Lithium ion battery pole piece and diaphragm compounding method and lithium ion battery
  • Lithium ion battery pole piece and diaphragm compounding method and lithium ion battery
  • Lithium ion battery pole piece and diaphragm compounding method and lithium ion battery

Examples

Experimental program
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Effect test

Embodiment 1

[0041] Preparation of positive electrode sheet

[0042] Mix the cathode active material LiNi according to the mass ratio of 93:4:3 0.7 co 0.1 mn 0.2 o 2 , conductive carbon black Super-P and binder polyvinylidene fluoride (PVDF), and then disperse them in N-methyl-2-pyrrolidone (NMP) to obtain positive electrode slurry. The slurry is evenly coated on both sides of the aluminum foil, and the positive electrode sheet is obtained through drying, calendering and vacuum drying. Then, at a temperature of 60° C., ethylene carbonate in molten state was coated on the surface of the positive electrode with a coating thickness of 5 μm, and then cooled to room temperature.

[0043] Preparation of negative electrode sheet

[0044] Mix negative electrode active material, conductive carbon black Super-P, binder styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) in a mass ratio of 94:1:2.5:2.5, and then disperse them in deionized water , to obtain negative electrode slurry...

Embodiment 2

[0049] Preparation of positive electrode sheet

[0050] Mix the cathode active material LiNi according to the mass ratio of 93:4:3 0.7 co 0.1 mn 0.2 o 2 , conductive carbon black Super-P and binder polyvinylidene fluoride (PVDF), and then disperse them in N-methyl-2-pyrrolidone (NMP) to obtain positive electrode slurry. The slurry is evenly coated on both sides of the aluminum foil, and the positive electrode sheet is obtained through drying, calendering and vacuum drying. Then, at a temperature of 60° C., vinylene carbonate in a molten state was coated on the surface of the positive electrode with a coating thickness of 5 μm, and then cooled to room temperature.

[0051] Preparation of negative electrode sheet

[0052] Mix negative electrode active material, conductive carbon black Super-P, binder styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) in a mass ratio of 94:1:2.5:2.5, and then disperse them in deionized water , to obtain negative electrode slur...

Embodiment 3

[0057] Preparation of positive electrode sheet

[0058] Mix the cathode active material LiNi according to the mass ratio of 93:4:3 0.7 co 0.1 mn 0.2 o 2 , conductive carbon black Super-P and binder polyvinylidene fluoride (PVDF), and then disperse them in N-methyl-2-pyrrolidone (NMP) to obtain positive electrode slurry. The slurry is evenly coated on both sides of the aluminum foil, and the positive electrode sheet is obtained through drying, calendering and vacuum drying. Then, at a temperature of 40°C, 1,3-propane sultone in a molten state was coated on the surface of the positive electrode with a coating thickness of 5 μm, and then cooled to 15°C.

[0059] Preparation of negative electrode sheet

[0060] Mix negative electrode active material, conductive carbon black Super-P, binder styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) in a mass ratio of 94:1:2.5:2.5, and then disperse them in deionized water , to obtain negative electrode slurry. Coating ...

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Abstract

In order to solve the problems that in the prior art, a battery cell pole piece and a diaphragm are not tightly compounded, and the lithium supplementing process is safe or incomplete, the invention provides a method for tightly compounding the pole piece and the diaphragm and safely and thoroughly supplementing lithium. The method comprises the following steps: uniformly mixing lithium powder and a solvent to obtain a lithium powder mixture; coating the lithium powder mixture on the surface of the negative plate in a molten state of the solvent; in the melting state of the solvent without the lithium powder, coating the surface of the positive plate with the solvent free from the lithium powder; sequentially laminating the negative plate coated with the lithium powder mixture, the diaphragm and the positive plate coated with the solvent free from the lithium powder, and winding or laminating to form a battery cell; and carrying out hot pressing on the battery cell, and then cooling to obtain the pole piece and diaphragm compounded battery cell. According to the invention, not only is the problem that the battery cell is loose after winding and lamination solved, but also pole piece diaphragm compounding and negative electrode lithium supplement are combined together, and the assembly process is simplified.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a composite method for a pole piece and a diaphragm of a lithium ion battery. Background technique [0002] Lithium-ion batteries are currently the most widely used commercial battery technology due to their high voltage, long cycle life, low self-discharge rate, and high energy density. [0003] At present, the manufacturing process of lithium-ion batteries is mainly winding and stacking. The production efficiency of the winding process is high, and the assembly process is relatively simple. However, due to the difficulty in controlling the tension during the winding process and the influence of the tension of the pole piece diaphragm, the wound cell is relatively loose. To improve the space utilization, the cell needs to be compressed. However, high pressure will cause excessive stress at the bend, which will easily cause material drop, resulting in a decrease in...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M50/46H01M50/403H01M10/0525H01M10/0583H01M10/0587
CPCH01M10/0525H01M10/0587H01M10/0583Y02P70/50Y02E60/10
Inventor 沈晞王晶
Owner 深圳市懋略技术研究有限公司