Negative plate and lithium ion battery

A lithium-ion battery and negative electrode technology, which is applied to battery electrodes, secondary batteries, non-aqueous electrolyte battery electrodes, etc., can solve the problems of easy volume expansion of silicon materials, poor cycle performance, and large expansion of negative electrode plates, so as to achieve a good cycle. performance, control of volume expansion, and the effect of improving cycle performance

Pending Publication Date: 2021-12-03
ZHUHAI COSMX BATTERY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, the volume of silicon material is easy to expand, which causes the negative electrode sheet containing silicon material to expand too much during the charging and discharging process, which affects the cycle performance of lithium-ion batteries, and as the content of silicon material in the negative electrode sheet gradually increases, the expansion rate increases , the cycle performance will be worse, therefore, how to improve the problem of easy volume expansion of silicon materials and improve the cycle performance of lithium-ion batteries has received more and more attention

Method used

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  • Negative plate and lithium ion battery
  • Negative plate and lithium ion battery
  • Negative plate and lithium ion battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] The negative electrode sheet provided in this embodiment includes a negative electrode current collector copper foil and a first negative electrode active layer, wherein,

[0046] The first negative electrode active layer comprises 96.5 mass parts of negative electrode active material, 1 mass part of conductive agent, 1.5 mass parts of PAA binder and 1 mass part of dispersant CMC;

[0047] Among them, the negative electrode active material includes graphite and SiO 1.2 , graphite and SiO 1.2 The mass ratio is 85:15;

[0048] The D10 of graphite is 6 μm, the D50 is 13 μm, and the D90 is 29 μm;

[0049] SiO 1.2 The D10 is 0.6μm, the D50 is 6.7μm, and the D90 is 12μm;

[0050] Conductive agent comprises carbon tube and carbon black, and the mass ratio of carbon tube and carbon black is 1:1;

[0051] The thickness of the copper foil is 6 μm, and the thickness of the first negative electrode active layer is 60 μm;

[0052] The preparation method of the negative plate p...

Embodiment 2

[0057] The negative electrode sheet provided in this example and its preparation method can refer to Example 1, the difference is that the negative electrode active material includes graphite and SiO 1.2 , graphite and SiO 1.2 The mass ratio is 93:7;

[0058] The same method as in Example 1 is used for statistics, and the SiO in the first negative active layer provided by this example 1.2 The average number of particles in the thickness direction of the first negative electrode active layer is 3.5, and the average number of particles in every 50 μm*50 μm area is 25.

[0059] The M value calculated in this embodiment is 1.98.

Embodiment 3

[0061] The negative electrode sheet provided in this example and its preparation method can refer to Example 1, the difference is that the negative electrode active material includes graphite and SiO 1.2 , graphite and SiO 1.2 The mass ratio is 99:1;

[0062] The same method as in Example 1 is used for statistics, and the SiO in the first negative electrode active layer provided by this example is counted. 1.2 The average number of particles in the thickness direction of the first negative electrode active layer is 1.5, and the average number of particles in a region of 50 μm*50 μm is 5.

[0063] The M value calculated in this embodiment is 0.33.

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Abstract

The invention provides a negative plate and a lithium ion battery. According to one embodiment, the invention provides a negative plate, the negative plate comprises a negative electrode current collector and a negative electrode active layer arranged on at least one functional surface of the negative electrode current collector, the negative electrode active layer comprises a first negative electrode active layer, and the first negative electrode active layer comprises a silicon material and a carbon material; in the thickness direction of the first negative electrode active layer, N silicon materials are distributed in the first negative electrode active layer in a linear arrangement mode, and the average particle number of the silicon materials in each linear arrangement is 1.5-5.5; the number of particles of the silicon material in an area of 50microns*50microns is 5-50. The negative plate provided by the invention can effectively improve the cycle performance of the lithium ion battery.

Description

technical field [0001] The invention relates to a negative electrode sheet and a lithium ion battery, and relates to the technical field of lithium ion batteries. Background technique [0002] Nowadays, lithium-ion batteries have become the energy storage devices of mainstream electronic products. With the continuous improvement of people's requirements for the battery life and charging capacity of electronic products, higher requirements are placed on the energy density of lithium-ion batteries. Silicon materials have a high specific capacity, and it has become an industry trend to increase the energy density of lithium-ion batteries by using a mixture of silicon materials and carbon materials as negative electrode active materials. [0003] However, the volume of silicon material is easy to expand, which causes the negative electrode sheet containing silicon material to expand too much during the charging and discharging process, which affects the cycle performance of lith...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): H01M4/13H01M4/62H01M10/0525
CPCH01M10/0525H01M4/13H01M4/625H01M2004/027H01M2004/021Y02E60/10
Inventor韦世超彭冲李俊义陈博
OwnerZHUHAI COSMX BATTERY CO LTD