Negative electrode composite slurry and preparation method thereof, lithium battery negative electrode sheet

A technology of composite slurry and negative electrode, applied in the field of negative electrode composite slurry and its preparation, can solve the problems of blocking lithium ion diffusion channels, affecting the rate performance of lithium batteries, increasing battery impedance, etc., and achieving good lithium ion transmission effect and isolation. Good thermal effect, reducing clogging effect

Active Publication Date: 2021-03-23
ETRUST POWER ETP GRP LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The usual practice is to apply ceramic coating on the diaphragm of polymer materials, but even if the diaphragms currently used in the market are coated with ceramics, there are still certain safety risks. If the battery is overheated locally, the diaphragm will also shrink, causing the positive and negative electrodes to be damaged. Chips are directly shorted, prone to thermal runaway
However, pure ceramic powder coating will block the diffusion channel of lithium ions on the positive and negative electrodes to a certain extent, thus causing the impedance of the battery to increase, thereby affecting the rate performance of the lithium battery.

Method used

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  • Negative electrode composite slurry and preparation method thereof, lithium battery negative electrode sheet
  • Negative electrode composite slurry and preparation method thereof, lithium battery negative electrode sheet
  • Negative electrode composite slurry and preparation method thereof, lithium battery negative electrode sheet

Examples

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Comparison scheme
Effect test

Embodiment 1

[0033] A negative electrode composite slurry, comprising the following components in weight percentage: 1.20% ultrafine glass fiber; 17.22% aluminum oxide powder; 1.20% low-viscosity carboxymethyl cellulose; 0.40% high-viscosity carboxymethyl cellulose; Benzene emulsion 0.10%; and water 79.88%. Wherein, the solid content of the styrene-butadiene emulsion is 50%.

[0034] see figure 1 , a lithium battery negative electrode sheet, comprising a negative electrode active material layer 1, a negative electrode composite coating 2 and a negative electrode current collector 3, the upper and lower surfaces of the negative electrode current collector 3 are coated with a negative electrode active material layer 1, and on the negative electrode active material layer 1 Coated with negative electrode composite coating 2. Wherein, the negative electrode current collector 3 may be copper foil.

[0035] A method for preparing a lithium battery negative pole piece, comprising the following ...

Embodiment 2

[0042] A negative electrode composite slurry, comprising the following components in weight percentage: 1.20% ultrafine glass fiber; 17.22% aluminum oxide powder; 1.10% low-viscosity carboxymethyl cellulose; 0.50% high-viscosity carboxymethyl cellulose; Benzene emulsion 0.10%; and water 79.88%. Wherein, the solid content of the styrene-butadiene emulsion is 50%.

[0043] A method for preparing a lithium battery negative pole piece, comprising the following steps:

[0044] 1) According to the formulation amount, mix low-viscosity carboxymethyl cellulose, high-viscosity carboxymethyl cellulose and water, put them into a planetary mixer for stirring and mixing, and obtain a dispersed aqueous solution.

[0045] 2) Mix ultrafine glass fiber and alumina powder evenly to obtain a mixture, add a predetermined amount of dispersion solution to the mixture, the predetermined amount of dispersion solution accounts for 8% of the total mass of the dispersion solution, stir for 40 minutes, ...

Embodiment 3

[0050] A negative electrode composite slurry, comprising the following components in weight percentage: 1.00% ultrafine glass fiber; 17.42% boehmite powder; 1.20% low-viscosity carboxymethyl cellulose; 0.40% high-viscosity carboxymethyl cellulose; Benzene emulsion 0.10%; and water 79.88%. Wherein, the solid content of the styrene-butadiene emulsion is 50%.

[0051] A method for preparing a lithium battery negative pole piece, comprising the following steps:

[0052] 1) According to the formulation amount, mix low-viscosity carboxymethyl cellulose, high-viscosity carboxymethyl cellulose and water, put them into a planetary mixer for stirring and mixing, and obtain a dispersed aqueous solution.

[0053] 2) Mix ultrafine glass fiber and boehmite powder evenly to obtain a mixture, add a predetermined amount of dispersion solution to the mixture, the predetermined amount of dispersion solution accounts for 10% of the total mass of the dispersion solution, stir for 30 minutes, stir...

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Abstract

The invention discloses negative electrode composite slurry and a preparation method thereof, and a lithium battery negative electrode plate. The negative electrode composite slurry comprises the following components in percentage by weight: 1.00 to 3.20% of superfine glass fibers, 16.20 to 23.50% of ceramic powder, 0.90-3.50% of a binder I, 0.10 to 0.80% of a binder II, 0.05 to 0.30% of styrene-butadiene emulsion or styrene-acrylic emulsion and 71.20 to 81.75% of water. A preparation method of the negative electrode composite slurry comprises the following steps: 1) obtaining a dispersed aqueous solution; 2) obtaining premixed slurry; and 3) obtaining the negative electrode composite slurry. The scheme of the invention has the advantages that the superfine glass fibers and the ceramic powder are mixed in the negative electrode composite slurry, so that the superfine glass fibers and the ceramic powder are evenly dispersed, the safety performance of the lithium battery is effectively improved, a negative electrode coating has a good lithium ion transmission effect, and the rate performance of the lithium battery is ensured.

Description

technical field [0001] The invention relates to the field of lithium battery negative pole pieces, in particular to a negative electrode composite slurry, a preparation method thereof, and a lithium battery negative pole piece. Background technique [0002] As the market demands higher and higher battery energy density, ternary materials, as a high-profile battery material, have a high discharge platform and high energy density, and more and more ternary materials are used in lithium batteries. However, due to its relatively poor thermal stability and the frequent spontaneous combustion incidents of electric vehicles in recent years, the market is currently looking for ways to safely and effectively avoid thermal runaway of the battery cell. [0003] Lithium batteries are usually mainly composed of positive electrodes, negative electrodes, diaphragms, electrolytes, and battery casings. The usual practice is to apply ceramic coating on the diaphragm of polymer materials, but...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/62H01M4/13H01M10/052
CPCY02E60/10
Inventor 王文帅陈启多程君陈星
Owner ETRUST POWER ETP GRP LTD
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