Preparation method of composite diaphragm, composite diaphragm and lithium ion battery

A composite diaphragm and base film technology, which is applied in the field of lithium-ion batteries, can solve the problems of poor bonding effect, no pole piece bonding effect, and no diaphragm sticking, etc., and achieve the effect of improving the bonding effect

Active Publication Date: 2020-09-11
东莞市魔方新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the composite diaphragm prepared by this method has the following problems: 1) Since the inorganic ceramic particles and organic bonding particles are randomly dispersed in the solvent, they are not evenly dispersed in the solvent, and there will be many organic bonding particles. The bonding effect between the place and the diaphragm is good, and the bonding effect between the place with few organic bonding parti

Method used

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  • Preparation method of composite diaphragm, composite diaphragm and lithium ion battery
  • Preparation method of composite diaphragm, composite diaphragm and lithium ion battery
  • Preparation method of composite diaphragm, composite diaphragm and lithium ion battery

Examples

Experimental program
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Effect test

Example Embodiment

[0032] A method for preparing a composite diaphragm includes the following operations:

[0033] Placing the inorganic particles 2 in the first solvent to obtain an inorganic slurry, coating the inorganic slurry on at least one surface of the base film 1 at intervals, and drying to obtain an inorganic thermally stable coating;

[0034] The organic particles 3 are dissolved in the second solvent to obtain an organic slurry, and the organic slurry is intermittently coated on the surface of the base film 1 between the inorganic thermally stable coatings to obtain an organic bonding coating; wherein, the organic bonding The thickness of the coating is greater than that of the inorganic thermally stable coating, and a composite diaphragm is obtained after drying.

Example Embodiment

[0035] Example 1

[0036] This embodiment provides a lithium ion battery, the preparation method of which is as follows:

[0037] (1) Preparation of composite diaphragm:

[0038] Take polyethylene microporous film with a thickness of 16um as the base film;

[0039] Preparation of inorganic thermally stable coating: adding Al in deionized water 2 O 3 Particle (Al 2 O 3 The average particle size of the particles is 1 μm) after stirring for 2 hours, grinding in a ball mill for 1 hour, and adding sodium carboxymethyl cellulose (CMC) to the ground slurry and stirring for 1 hour to prepare an inorganic slurry. The gravure coating method is used to coat the two sides of the base film with inorganic slurry so that the Al 2 O 3 The particles are arranged in island-like intervals on the surface of the base film to obtain an inorganic thermally stable coating with a thickness of 5 μm, which is ready for use after drying;

[0040] Preparation of organic bonding coating: Add polyvinylidene fluoride...

Example Embodiment

[0045] Example 2

[0046] This embodiment provides a lithium ion battery. The difference from Embodiment 1 is the preparation of the composite diaphragm:

[0047] Take a glass fiber membrane with a thickness of 16um, synthesize a polyamic acid solution and dissolve it in DMAc, then apply the mixed solution to the glass fiber membrane, first heat up to 60°C for 30 minutes; then heat up to 120°C for 30 minutes; then heat up Keep it at 200°C for 60 minutes, dry to remove excess solvent, vacuum dry to complete the imidization reaction, and obtain a polyimide-glass fiber composite film as the base film;

[0048] Preparation of inorganic thermally stable coating: adding Al in deionized water 2 O 3 Particle (Al 2 O 3 The average particle size of the particles is 1 μm) after stirring for 2 hours, grinding in a ball mill for 1 hour, and adding sodium carboxymethyl cellulose (CMC) to the ground slurry and stirring for 1 hour to prepare an inorganic slurry. The gravure coating method is used t...

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Abstract

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a preparation method of a composite diaphragm. The preparation method comprises the following steps:putting inorganic particles into a first solvent to obtain inorganic slurry, coating at least one surface of a base membrane with the inorganic slurry at intervals, and drying to obtain an inorganic heat-stable coating; putting organic particles into a second solvent to obtain organic slurry, and coating the surface of the base film between the inorganic heat-stable coatings with the organic slurry at intervals to obtain an organic bonding coating, wherein the thickness of the organic bonding coating is greater than that of the inorganic heat-stable coating; and drying to obtain the compositediaphragm. According to the invention, the problems that inorganic particles and organic particles cannot be regularly arranged, the organic particles can be buried by the inorganic particles, and thebonding effect of the organic particles, a base film and a pole piece is poor are solved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a preparation method of a composite diaphragm, a composite diaphragm and a lithium ion battery. Background technique [0002] Since the commercialization of lithium-ion batteries in the 1990s, due to their high energy density, high operating voltage, and light weight, they have been widely used in mobile phones, notebook computers, tablet computers, Bluetooth headsets, MP3, and digital cameras. . [0003] Lithium-ion batteries are mainly composed of positive and negative pole pieces and a separator in the middle. The separator is used as the isolation of the positive and negative electrodes to prevent the short circuit from direct contact between the positive and negative electrodes. At present, the separator is mainly a porous medium composed of polyolefins such as polyethylene and polypropylene. The polyolefin separator has a melting point of 200°C or...

Claims

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Application Information

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IPC IPC(8): H01M2/14H01M2/16H01M2/18H01M10/0525
CPCH01M10/0525H01M2220/30Y02E60/10
Inventor 汪圣龙蒋中林
Owner 东莞市魔方新能源科技有限公司
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