Ceramic coating membrane and preparation method thereof

A technology of ceramic coating and diaphragm, applied in the direction of electrical components, circuits, battery pack components, etc., can solve the problem of affecting the uniformity of the dispersion of the ceramic coating layer on the surface of the diaphragm, the agglomeration or uneven dispersion of ceramic powder, and the infiltration of electrolyte in the isolation membrane. Low capacity and other problems, to achieve the effect of improving the wetting capacity of the electrolyte, not easy to fall off and separate, improving hydrophilicity and ion exchange capacity

Active Publication Date: 2012-07-11
SHENZHEN SENIOR TECH MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Recently, there have also been composite separators of ceramic powders and polyolefin separators to prepare lithium-ion batteries. However, these existing composite separators of ceramic powders and polyolefin separators are simply suspended ceramic powders in solvents or bonded. In the solvent solution, the surface of the ceramic powder has not been treated in any way, so that the existing isolation membrane electrolyte has low wettability and poor safety performance.
At the same time, since the ceramic powder is not processed, it also brings about the existence of agglomeration or uneven dispersion of the ceramic powder, which directly affects the uniformity of the dispersion of the ceramic coating layer on the surface of the diaphragm, thus causing the problem of uneven performance of the diaphragm product.

Method used

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  • Ceramic coating membrane and preparation method thereof
  • Ceramic coating membrane and preparation method thereof
  • Ceramic coating membrane and preparation method thereof

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preparation example Construction

[0022] The embodiment of the present invention provides a method for preparing a ceramic coated diaphragm with electrolyte infiltration capability and high safety. The process flow is as follows: figure 1 Shown. The preparation method of the ceramic coated diaphragm includes the following steps:

[0023] S01. Preparation of grafted ceramic powder:

[0024] Grafting the benzenesulfonic acid derivative to the surface of the ceramic powder under the action of the dehydrating agent to obtain the grafted ceramic powder, and washing the grafted ceramic powder;

[0025] S02. Preparation of functional micropowders containing lithium ions:

[0026] Subjecting the washed grafted ceramic powder to an ion replacement reaction in a LiOH aqueous solution to obtain a functional micropowder containing lithium ions;

[0027] S03. Preparation of coating slurry:

[0028] Mixing the functional micropowder and the binder solution to prepare a coating slurry; wherein the mass ratio of the functional micropow...

Embodiment 1

[0045] A method for preparing a ceramic coated diaphragm includes the following steps:

[0046] S11: Take 10g of submicron aluminum oxide powder, 5-sodium isophthalate and 2g DCC respectively, and dissolve 5-sodium isophthalate and DCC in 200ml ethanol at 65℃ , N 2 In a water bath for 2 hours under the atmosphere, the grafting reaction is carried out. After the grafting reaction is completed, the grafted ceramic powder is refluxed in ethanol for 4 hours for purification;

[0047] S12: Add a 27% LiOH aqueous solution to the washed grafted ceramic powder and reflux for 48 hours at 100°C to remove -SO on the surface of the grafted ceramic powder. 2 Na group is converted to SO 3 Li group, fully washed with water until the PH value is neutral, and the functional group on the surface is SO 3 Li's functional ceramic powder;

[0048] S13: Mix lithium polystyrene sulfonate and N,N-dimethylformamide at a mass ratio of 1:1 at 50°C for 2 hours, and then add the functional ceramic powder in step ...

Embodiment 2

[0051] A method for preparing a ceramic coated diaphragm includes the following steps:

[0052] S21: Refer to step S11 of Example 1, to obtain a purified grafted ceramic powder;

[0053] S22: Refer to step S12 of Example 1, to obtain the functional group on the surface as SO 3 Li's functional ceramic powder;

[0054] S23: Refer to step S12 of embodiment 1 to obtain a coating slurry;

[0055] S24: Immerse the PP microporous film in the coating slurry prepared in step S23 above, so that the PP microporous film (thickness 20um) is completely infiltrated by the coating slurry, then remove the film from the clip, and drain the remaining slurry on the surface , Spread it out and hang it in a vacuum drying box, and dry it at 80°C for 30 minutes to prepare a ceramic coated diaphragm with a functional layer on both sides.

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Abstract

The invention discloses a ceramic coating membrane and a preparation method thereof. The steps are as follows: the preparation of stem grafting ceramic powder, the preparation of functional power containing lithium-ion, the preparation of coating slurry and the preparation of ceramic coating membrane. The preparation method of ceramic coating membrane, provided by the invention is that: benzene sulfonate containing lithium is grafted on the surface of the ceramic powder, and then the ceramic powder grafted is coated on a polyolefin microporous membrane, thereby obtaining the ceramic coating membrane is obtained. The preparation method has the advantages of simple process, low requirements to equipment, easiness in condition control and low cost, and is suitable for industrial production. Due to the ion exchange capacity and hydrophily of the ceramic coating membrane prepared by the method, the ceramic coating membrane has a strong electrolyte infiltrating capability, is high in membrane breaking temperature, and has improved safety.

Description

Technical field [0001] The invention belongs to the technical field of lithium ion batteries, and specifically relates to a ceramic coating diaphragm for lithium ion batteries and a preparation method thereof. Background technique [0002] At present, polyolefin microporous film materials have been used in more and more applications and developments. The most extensive application is currently used as an isolation membrane material for lithium-ion batteries, becoming one of the key internal components of lithium-ion batteries. The isolation membrane has a crucial influence on the performance of the actual battery. It must have good chemical and electrochemical stability and maintain a high degree of wettability to the electrolyte during repeated charge and discharge. The interface compatibility between the isolation membrane material and the electrode and the retention of the isolation membrane to the electrolyte have a greater impact on the charge and discharge performance and c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16
CPCY02E60/12Y02E60/10
Inventor 陈秀峰陈良杨佳富雷彩红王今刚何方波
Owner SHENZHEN SENIOR TECH MATERIAL
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