Negative pole piece as well as preparation method thereof, and lithium ion battery

A technology of negative electrode sheet and negative electrode is applied in the field of negative electrode sheet and its preparation, which can solve problems such as hidden dangers of battery safety, and achieve the effects of reducing the occurrence probability, lowering the edge coating amount, and reducing safety accidents.

Inactive Publication Date: 2018-07-06
湖南三迅新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a negative electrode sheet and a preparation method thereof, and to provide a negative electrode sheet and a preparation method thereof, and to provide a negativ...

Method used

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  • Negative pole piece as well as preparation method thereof, and lithium ion battery
  • Negative pole piece as well as preparation method thereof, and lithium ion battery
  • Negative pole piece as well as preparation method thereof, and lithium ion battery

Examples

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preparation example Construction

[0047] Simultaneously, the present invention also provides the preparation method of above-mentioned negative plate, comprises the following steps:

[0048] providing a slurry of the first negative electrode material;

[0049] providing a slurry of the second negative electrode material;

[0050] Coating the slurry of the first negative electrode material on the surface of the negative electrode current collector 1 to form a first negative electrode material layer 21, the first negative electrode material layer 21 includes a first material region 211 and a second material region at the edge of the first material region 211 212, the thickness of the first material region 211 is greater than the thickness of the second material region 212, the slurry material of the second negative electrode material is coated on the surface of the second material region 212 to form a second negative electrode material layer 22, and then dried to form a negative electrode Material layer 2, to o...

Embodiment 1

[0067] 1. Preparation of negative electrode sheet

[0068] 1.1 Slurry preparation of the first negative electrode material.

[0069] First prepare CMC (sodium carboxymethylcellulose) into an aqueous solution;

[0070] Add conductive carbon black in the CMC aqueous solution and mix and stir, then add artificial graphite (produced by Shenzhen Beiterui New Energy Materials Co., Ltd., the gram capacity is 360mAH / g) and continue to stir;

[0071] Then add SBR (styrene-butadiene rubber) emulsion and continue to mix and stir evenly. Wherein the weight ratio of artificial graphite: conductive carbon black: CMC: SBR is 96:1:1.5:1.5.

[0072] 1.2 Preparation of slurry for the second negative electrode material.

[0073] First prepare CMC into an aqueous solution;

[0074] Add conductive carbon black to the CMC aqueous solution for mixing and stirring, then add silicon oxide carbon composite material (purchased from Shenzhen Betterui New Energy Materials Co., Ltd., the gram capacity ...

Embodiment 2

[0086] Negative electrode sheets, positive electrode sheets, and lithium-ion batteries were prepared according to the method of Example 1, the difference being that the weight ratio of artificial graphite:CMC:SBR in the slurry of the first negative electrode material was 98:1:1.

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Abstract

The invention belongs to the field of lithium ion batteries and relates to a negative pole piece. The negative pole piece comprises a negative current collector and a negative material layer adhered onto the surface of the negative current collector; the negative material layer comprises a first negative material layer and a second negative material layer; the first negative material layer comprises a first material area and a second material area positioned on the edge of the first material area and is adhered onto the surface of the negative current collector; the thickness of the first material area is greater than that of the second material area; the second negative material layer is adhered onto the surface of the second material area and is positioned on the edge of the first negative material layer. The negative pole piece provided by the invention has the benefits that the risk of battery short-circuit caused by potential production of lithium dendrites due to relatively low edge coating weight of a conventional negative sheet is reduced, the occurrence probability of safety accidents of the lithium ion battery is reduced, and the safety performance of the lithium ion battery is improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a negative electrode sheet, a preparation method thereof, and a lithium ion battery including the negative electrode sheet. Background technique [0002] Lithium-ion batteries have been widely used in the electronic field due to their high energy density, high cycle life, and low self-discharge performance since they were first commercialized by Sony Corporation of Japan in the 1990s. With the rapid development of industry and economy, the contradiction between oil supply and demand and environmental pollution have become increasingly prominent, and countries have taken the development of new energy vehicles as a national strategy. In the past three years, the utilization rate of domestic new energy vehicles has been growing rapidly, and new energy vehicles use lithium-ion batteries, which has led to a sharp increase in the production and sales of lithiu...

Claims

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Application Information

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IPC IPC(8): H01M4/131H01M4/133H01M4/134H01M4/1391H01M4/1393H01M4/1395H01M4/36H01M10/0525
CPCH01M4/131H01M4/133H01M4/134H01M4/1391H01M4/1393H01M4/1395H01M4/366H01M10/0525Y02E60/10
Inventor 玉正日冯晓杰梁世硕周文对
Owner 湖南三迅新能源科技有限公司
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