Separator for battery and preparation method thereof

A separator and battery technology, applied in the field of battery separators and their preparation, can solve problems such as poor bonding performance, and achieve the effects of improving rate discharge and cycle performance, excellent bonding performance, and bonding force.

Active Publication Date: 2020-02-04
HEBEI GELLEC NEW ENERGY MATERIAL SCI&TECHNOLOY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] An object of the present invention is to provide a separator for batteries, including a base film, and a PVDF / PMMA (Polymethyl methacrylate, polymethyl methacrylate) composite coating coated on at least one surface of the base film, to alleviate the existing The technical problem of poor bonding performance between PVDF diaphragm and battery pole piece in the technology

Method used

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  • Separator for battery and preparation method thereof
  • Separator for battery and preparation method thereof
  • Separator for battery and preparation method thereof

Examples

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preparation example Construction

[0056] According to a second aspect of the present invention, the method for preparing a separator for a battery as described above comprises the following steps:

[0057] A PVDF / PMMA composite coating is sprayed on at least one side of the base film and dried to obtain a separator for batteries.

[0058] The principle of spraying: the required spraying material is transported to the rotary table by pressure through the magnetic pump, so that the rotary table rotates at a high speed, the material is cut into small droplets in the rotary table, and the cut droplets are thrown out to the film by centrifugal force .

[0059] The present invention sprays the PVDF / PMMA composite coating on the base film by means of spraying. The method is simple to operate, and the PVDF / PMMA composite coating sprayed in dots is relatively thin, and the diameter of the dots is 0.01-2mm, which can ensure the The air permeability of the battery can be enhanced, and the adhesion between the separator ...

Embodiment 1

[0070] A diaphragm for a battery comprises a polyimide base film and a PVDF / PMMA composite coating coated on one side of the polyimide base film.

[0071] The preparation method of the separator for the battery comprises the following steps:

[0072] Add 32 parts of PVDF and 9 parts of polyoxyethylene alkylphenol ether to 175 parts of water, mix and stir for 118 minutes to disperse evenly, then add 125 parts of PMMA solution and stir for 32 minutes, then add 4 parts of povidone and 5 parts of polyethylene glycol Glycol and 23 parts of α-cyanoacrylate are stirred evenly to obtain a mixed slurry of PVDF and PMMA; using a spraying process, the mixed slurry of PVDF and PMMA is sprayed on one side of a polyimide base film with a thickness of 12um, and the coating The thickness is 0.8um, and then dried in an oven at 40° C. for 3 minutes to obtain a battery separator.

Embodiment 2

[0074] A diaphragm for a battery comprises a polyimide base film and a PVDF / PMMA composite coating coated on one side of the polyimide base film.

[0075] The preparation method of the separator for the battery comprises the following steps:

[0076] Add 28 parts of PVDF and 14 parts of sodium polyacrylate to 185 parts of water, mix and stir for 122 minutes to disperse evenly, then add 115 parts of PMMA solution and stir for 36 minutes, then add 5 parts of polyethylene glycol, 5 parts of povidone, 4 parts Carboxymethyl cellulose and 20 parts of polybutyl acrylate are stirred evenly to obtain a mixed slurry of PVDF and PMMA; using a spraying process, the mixed slurry of PVDF and PMMA is sprayed on one side of a polyimide base film with a thickness of 12um, The thickness of the coating was 1.2um, and then dried in an oven at 50° C. for 2 minutes to obtain a separator for batteries.

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Abstract

The invention belongs to the technical field of batteries, and particularly relates to a battery diaphragm and a preparation method thereof. The battery diaphragm provided by the invention comprises abase film and a PVDF / PMMA composite coating arranged on at least one side face of the base film in a coating manner; and preferably, the battery diaphragm comprises a base film and PVDF / PMMA composite coatings arranged on both sides of the base film in a coating manner. According to the battery diaphragm provided by the invention, a PVDF / PMMA composite coating is obtained by spraying a mixed slurry of PVDF and PMMA on at least one side face of the base film in a spraying manner, and the prepared battery diaphragm has low air permeability value added, has excellent bonding performance, needlepunching strength, tensile strength and heat shrinkage performance, and can improve the rate discharge and cycle performance of the battery.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a separator for batteries and a preparation method thereof. Background technique [0002] Coated separators are becoming more and more widely used in battery applications. They are a very critical part of the battery and have a direct impact on battery safety and cost. The ions in the liquid pass freely between the positive and negative electrodes. The coating classification mainly includes: alumina coating, boehmite coating, aramid fiber coating and composite coating of alumina and boehmite. [0003] The diaphragm coating process is generally divided into micro gravure coating process and spray coating process. With people's in-depth understanding of the spraying process, PVDF (Polyvinylidene difluoride, polyvinylidene fluoride) sprayed diaphragms have gradually entered people's field of vision. The PVDF coated separator mainly uses the principle of gel electrolyte in the a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M2/14H01M2/16
CPCH01M50/403H01M50/411H01M50/449Y02E60/10
Inventor 徐锋袁海朝贾亚峰苏碧海
Owner HEBEI GELLEC NEW ENERGY MATERIAL SCI&TECHNOLOY CO LTD
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