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Ceramic diaphragm for lithium ion battery and lithium ion battery

A technology of lithium-ion batteries and ceramic diaphragms, which is applied in secondary batteries, battery pack components, circuits, etc., can solve problems such as adverse effects of the environment and users, ceramic diaphragms are easy to powder, and insufficient bonding strength, etc., to achieve improvement Safety performance and cycle performance, reduction of adverse effects, effects of high bonding strength

Active Publication Date: 2020-09-15
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the scheme provided by CN201210444056.7, due to the insufficient bonding strength between the inorganic particles and the binder, the prepared ceramic separator is easy to drop powder, which will affect the battery performance such as cycle
However, in the scheme provided by CN201310533838.2, due to the use of a large amount of binder, the gas permeability of the ceramic diaphragm is deteriorated, and the output characteristics of the battery are affected.
[0005] In addition, the same as the above two patents, acrylonitrile monomers are often used in the existing ceramic diaphragms in the prior art, although the use of such acrylonitrile monomers can improve the cohesive energy density of the binder , however, because this acrylonitrile monomer is highly toxic, it is easy to cause adverse effects on the environment and users

Method used

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  • Ceramic diaphragm for lithium ion battery and lithium ion battery
  • Ceramic diaphragm for lithium ion battery and lithium ion battery
  • Ceramic diaphragm for lithium ion battery and lithium ion battery

Examples

Experimental program
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preparation example Construction

[0035] In the present invention, the above-mentioned ceramic separator for lithium-ion batteries can be prepared in a conventional manner in the art, as long as the raw materials mentioned above in the present invention are used. Wherein, an optional preparation method includes the following steps: mixing ceramic particles, dispersant and water, stirring once, adding an optional surface treatment agent and stirring twice to form a slurry of ceramic particles; Adding binder emulsion, optional surfactant and optional thickener to the particle slurry, stirring three times, coating the ceramic coating obtained by stirring on at least one surface of the substrate layer, drying to form the A ceramic separator for a lithium-ion battery.

[0036] Preferably, the preparation method of the above-mentioned binder emulsion comprises: the first monomer (acrylate monomer), the second monomer (acrylic acid and / or acrylate) and the third monomer (methylol acrylate and / or or methylol acrylami...

Embodiment 1 to 20

[0049] It is used to illustrate the raw materials and proportions in the ceramic coating for forming the ceramic diaphragm of the present invention, and the preparation method of the ceramic diaphragm. The substrate used in each example is a PE separator purchased from SK Company, and its thickness is 12 μm.

Embodiment 1

[0051] 2kg alumina (ceramic particles), 0.008kg sodium polyacrylate (dispersant, number average molecular weight is 15000), and the water that keeps the solid content of final alumina slurry is 25% is mixed, stirred at 5000 speed for 1.5 hours, Add 0.02kg of 3-glycidyloxypropyltrimethoxysilane, continue to stir for 1.5 hours at a speed of 5000 rpm, add 0.27kg of adhesive agent PA1 emulsion with a solid content of 30wt% (the particle size in the emulsion 200nm), the sodium dodecylbenzenesulfonate of 0.008kg, the sodium polyacrylate tackifier (number average molecular weight 450000) of 0.02kg, continue to stir 0.5 hour under 2000 rev / min speeds, obtain ceramic slurry, will The ceramic slurry was coated on both sides of the substrate layer, and dried at 75° C. to obtain a ceramic diaphragm with a total thickness of 6 μm of the ceramic coating on both sides of the substrate layer, denoted as S1.

[0052] Such as figure 1 as shown, figure 1 For adopting scanning electron microsco...

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Abstract

The invention discloses a ceramic diaphragm for a lithium ion battery and the lithium ion battery. The ceramic diaphragm for lithium ion battery comprises a substrate layer and a ceramic coating coated on at least one side surface of the substrate layer, the ceramic coating includes ceramic particles, a dispersant and a binding agent, and the binding agent is formed by the first A copolymer formed by copolymerization of a monomer, a second monomer and a third monomer, the first monomer is an acrylate monomer, the second monomer is acrylic acid and / or acrylate, and the third monomer is methacrylate esters and / or methylolacrylamide. The ceramic diaphragm of the present invention avoids the introduction of highly toxic acrylonitrile monomers, makes it safe and reliable during preparation and use, and reduces adverse effects on the environment and users. At the same time, in the above-mentioned ceramic diaphragm provided by the present invention, the binder formed by the copolymerization of the above-mentioned three specific polymerized monomers is used in conjunction with the ceramic material and the dispersant, which is conducive to the preparation of uniformly distributed, good air permeability, and bond strength. Large ceramic diaphragm.

Description

technical field [0001] The invention relates to the field of battery manufacturing, in particular to a ceramic diaphragm for a lithium ion battery and a lithium ion battery comprising the same. Background technique [0002] Lithium ion secondary batteries generally include an electrode assembly, a container housing the electrode assembly, and an electrolytic solution. Wherein the electrode assembly includes two electrodes with opposite polarities and a separator for preventing short circuit between the two electrodes. Existing separators usually use polyolefin organic separators such as PE. However, this type of separator has a low melting point and poor thermal stability. When the battery temperature rises due to internal or external stimuli, the organic separator may be damaged. Shrinkage or melting occurs, which leads to a short circuit between the positive and negative electrodes of the battery, causing the battery to burn or explode. In addition, this type of organic ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M2/16H01M10/0525C09D133/08C09D7/61C09D7/65H01M50/434H01M50/443H01M50/449
CPCH01M10/0525C09D133/08C08L2205/02C08L2205/025H01M50/446H01M50/449C08L33/02C08K9/06C08K3/00Y02E60/10
Inventor 鲁丹刘荣华高磊吴金祥单军
Owner BYD CO LTD