Negative electrode sheet and lithium ion battery comprising same

A technology of negative electrode sheet and negative electrode, which is applied in the direction of negative electrode, battery electrode, secondary battery, etc., can solve the problems of binder bond strength attenuation, negative electrode sheet expansion rate, swelling performance increase, etc., to reduce rebound , Small coverage, enhance the effect of negative plate structure

Pending Publication Date: 2021-08-10
ZHUHAI COSMX BATTERY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Compared with pure styrene-butadiene rubber, although the bonding performance and ion conductivity of the negative electrode sheet prepared from it can be improved by modification, it will also increase the swelling performance of the binder to the electrolyte (i.e. viscosity The liquid absorption performance of the binder is improved), which will lead to the attenuation of the bond strength of the binder, which will lead to the problem that the expansion rate of the negative electrode sheet becomes larger

Method used

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  • Negative electrode sheet and lithium ion battery comprising same
  • Negative electrode sheet and lithium ion battery comprising same
  • Negative electrode sheet and lithium ion battery comprising same

Examples

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preparation example Construction

[0039] The preparation method of the present invention will be further described in detail in conjunction with specific examples below. It should be understood that the following examples are only for illustrating and explaining the present invention, and should not be construed as limiting the protection scope of the present invention. All technologies realized based on the above contents of the present invention are covered within the scope of protection intended by the present invention.

[0040] The experimental methods used in the following examples are conventional methods unless otherwise specified; the reagents and materials used in the following examples can be obtained from commercial sources unless otherwise specified.

Embodiment 1

[0042] ①The preparation of the negative electrode sheet, by weight fraction, artificial graphite, thickener CMC, binder SBR, conductive agent SP, nanocellulose (diameter range 10-50nm, length 1-5μm) according to 96.3%: 1.5% : 1.5% : 0.5% : 0.2% by weight, mixed with deionized water and stirred evenly, prepared into negative electrode slurry, coated on both sides of negative electrode current collector copper foil (thickness is 6 μm), dried, rolled, separated After cutting and welding the negative electrode ear, the negative electrode sheet is obtained.

[0043] ②Preparation of the positive electrode sheet, by weight fraction, 98.0% of the positive electrode active material LiCoO 2 , 1.0% positive electrode binder polyvinylidene fluoride, and 1.0% positive electrode conductive agent SP are added to NMP, stirred evenly, coated on both sides of the positive electrode current collector aluminum foil (thickness is 9 μ m), after drying, rolling, cutting, The positive electrode piec...

Embodiment 2~7

[0047]The preparation method of the lithium-ion batteries of Examples 2-7 is the same as that of Example 1, except that the size of the nanocellulose is different, as shown in Table 1 for details.

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Abstract

The invention provides a negative electrode sheet and a lithium ion battery comprising the same. The negative electrode sheet comprises nano cellulose, wherein the nano cellulose is light in weight and high in strength, can enhance the structure of the negative electrode sheet and reduce rebound of the negative electrode sheet, is small in volume, is small in the coverage of a negative electrode active material, and does not bring large bulk phase impedance like a traditional negative electrode binder. The lithium ion battery comprising the negative electrode sheet has relatively excellent low-temperature charge-discharge performance, high-temperature storage performance and high-temperature stability performance.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a negative electrode sheet and a lithium ion battery including the negative electrode sheet. Background technique [0002] The negative electrode sheet is an important part of the lithium-ion battery, which is one of the important factors affecting the overall dynamic performance of the lithium-ion battery; at the same time, the lithium-ion battery has thickness growth and deformation during use, especially in high temperature environments. Structural changes that lead to battery swelling and increased cell resistance. This thickness increase is generally considered to be mainly from the rebound of the negative electrode sheet, and optimizing the formulation design of the negative electrode sheet is an important way to reduce the resistance of the cell and the expansion of the battery. [0003] At present, negative electrode sheets for lithium-ion batte...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/587H01M4/62H01M10/0525
CPCH01M4/587H01M4/625H01M10/0525H01M2004/027Y02E60/10
Inventor 陈伟平李素丽
Owner ZHUHAI COSMX BATTERY CO LTD
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