A kind of preparation method of negative pole piece of lithium battery

A technology for negative pole pieces and lithium batteries, which is applied in battery electrodes, electrode manufacturing, negative electrodes, etc., can solve the problems of negative pole piece powder dropping, etc., and achieve the effects of short production cycle, slowing down cell expansion, and low price

Active Publication Date: 2021-11-19
SHANGHAI ELECTRICGROUP CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the technical problem of reducing the SBR content in the negative electrode sheet in the prior art and causing the powder drop of the negative electrode sheet, the present invention provides a lithium battery negative electrode that solves the problem of powder drop of the negative electrode sheet due to the reduction in the amount of SBR added. Tablet preparation method

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  • A kind of preparation method of negative pole piece of lithium battery
  • A kind of preparation method of negative pole piece of lithium battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Preparation of negative electrode sheet 1:

[0031] Add 100g of silicon carbon, 1g of conductive agent, and 1.3g of CMC dry powder into the mixer, and stir evenly for 40 minutes. In order to improve the mixing effect, add 50g of deionized water in three times, add 30g of deionized water for the first time, and stir evenly for 30 minutes; the second time Add 10g of deionized water, stir evenly for 30 minutes, and make a slurry; finally add 10g of deionized water, stir for 30 minutes, mix well, add 1.3g of SBR (solid content 40%), 1.3g of sucrose, stir evenly for 30min, and the pulping is completed.

[0032] Put the slurry into the slurry buffer tank of the coating machine, evenly coat the two sides of the copper foil to form a wet film pole piece, put it into an oven at a temperature of 300°C, and dry it to obtain the negative pole piece 1 .

Embodiment 2

[0034] Preparation of negative electrode sheet 1:

[0035] Add 98.5g of deionized water to the blender, slowly add 1.5g of sodium carboxymethylcellulose, and stir evenly to make a CMC solution, and let it stand for 3 hours before use.

[0036] Add 100g of natural graphite and 1g of conductive agent to another mixer, stir evenly for 30min to form a solution, add 48g of CMC solution, stir evenly for 45min to form a high viscosity state; continue to add the remaining 52g of CMC solution, and stir evenly for 45min. Add 2.25g SBR (solid content 40%), 2.25g sucrose, stir evenly for 30min, pulping is completed.

[0037] Put the slurry into the slurry buffer tank of the coating machine, evenly coat the two sides of the copper foil to form a wet film pole piece, put it into an oven at a temperature of 300° C., and dry it to obtain the negative pole piece 2 .

[0038] Compared with the prior art, the lithium battery negative electrode sheet prepared by the present invention reduces the...

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Abstract

The invention discloses a method for preparing a negative electrode sheet of a lithium battery, comprising the following steps: step S1: mixing CMC, negative electrode active material, conductive agent and deionized water to form a solution A; step S2: continuing in the A solution Add SBR and carbon precursor, stir to form a slurry; step S3: apply the slurry on copper foil to form a wet film pole piece; step S4: heat the wet film pole piece to 270-330°C to obtain The negative electrode sheet of the lithium battery. The preparation method of the negative pole piece provided by the present invention reduces the addition of SBR, and by adding a small amount of carbon precursor, the carbon precursor is heated and decomposed to form carbon chains of functional groups such as carbonyl and double bonds, and then in the process of adding electrolyte and charging and discharging, Slow down the cell expansion caused by SBR swelling, and the pole piece itself will not lose powder due to the reduction of SBR addition.

Description

technical field [0001] The invention relates to the field of lithium-ion secondary batteries, in particular to a method for preparing a negative pole piece of a lithium battery. Background technique [0002] In the prior art, the reasons for the swelling of lithium-ion batteries are divided into three categories. One is that the thickness of the battery pole piece increases during the cycle; the other is the swelling caused by the oxidation and decomposition of the electrolyte; Bulging caused by process defects such as the introduction of moisture and corner damage. In different battery systems, the dominant factors of battery thickness change are different. For example, in lithium titanate negative electrode system batteries, the main factor of bulging is gas bulging; Play a promoting role. The swelling caused by the injection of electrolyte, because SBR is a flexible material, will expand and shrink as Li+ is deintercalated in the negative electrode. The current common ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/04H01M4/1399H01M4/60H01M10/0525
CPCH01M4/0416H01M4/1399H01M4/602H01M10/0525H01M2004/027Y02E60/10
Inventor 刘利霞耿振李斯剑高欣苏青廖文俊
Owner SHANGHAI ELECTRICGROUP CORP
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