Battery diaphragm, preparation method thereof, lithium ion battery and electric vehicle

A battery diaphragm and base film technology, which is applied in the direction of secondary batteries, battery components, circuits, etc., can solve the problems of uneven distribution of pore structure, poor thermal shrinkage resistance of the diaphragm, and low surface porosity of the battery diaphragm, and achieve Low shrinkage, prevent short circuit of positive and negative electrodes of battery, and improve strength

Active Publication Date: 2020-01-07
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] In order to overcome the defects of low surface porosity, uneven distribution of pore structure, and poor thermal shrinkage resistance of the separator in the prior art, the present invention provides a battery separator, which includes a p

Method used

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  • Battery diaphragm, preparation method thereof, lithium ion battery and electric vehicle
  • Battery diaphragm, preparation method thereof, lithium ion battery and electric vehicle

Examples

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Example Embodiment

[0044] In the second aspect, the present invention also provides a method for preparing a battery separator, wherein the method includes the following steps:

[0045] (1) Surface modification of polyethylene terephthalate to make it contain hydroxyl and / or carboxyl groups, or to make it have a carbon-carbon double bond to obtain modified polyethylene terephthalate;

[0046] (2) The modified polyethylene terephthalate and the acrylic polymer are mixed and melt-spun to form a polymer fiber layer.

[0047] According to the present invention, the method for modifying polyethylene terephthalate as described above has been fully introduced, and in order to avoid unnecessary repetition, it will not be repeated here.

[0048] Wherein, in step (1), the weight ratio of the silane coupling agent and polyethylene terephthalate is 0.05:1-0.5:1, and the silane coupling agent and polyethylene terephthalate The weight ratio of alcohol ester is controlled within the above range, and the modified polye...

Example Embodiment

[0082] Example 1

[0083] Follow the steps below to prepare the battery separator:

[0084] (1) First use 0.1mol / L silane coupling agent 3-acryloxypropyltrimethoxysilane N,N-dimethylformamide solution of polyethylene terephthalate at 60℃ Treated for 2h to obtain modified polyethylene terephthalate. The amount of silane coupling agent is such that the hydroxyl content and carboxyl content on the surface of polyethylene terephthalate are shown in Table 2.

[0085] (2) The modified polyethylene terephthalate prepared in step (1) is mixed with butyl acrylate-hydroxyethyl acrylate copolymer to obtain a polymer fiber layer composition. Wherein, the content of modified polyethylene terephthalate is 90% by weight, and the content of butyl acrylate-hydroxyethyl acrylate copolymer is 10% by weight. Heat and melt at 200℃, then electrospin on one surface of the PE base film, dry at 60℃ for 2 hours, spin on the other side in the same way after drying, and dry at 60℃ for 24 hours to obtain batt...

Example Embodiment

[0087] Example 2

[0088] (1) First use 0.2mol / L silane coupling agent 3-methacryloxypropyltrimethoxysilane N,N-dimethylformamide solution of polyethylene terephthalate in 50 Treated at ℃ for 3h to obtain modified polyethylene terephthalate. The amount of silane coupling agent is such that the hydroxyl content and carboxyl content on the surface of polyethylene terephthalate are shown in Table 2.

[0089] (2) Mix the modified polyethylene terephthalate prepared in step (1) with butyl acrylate-hydroxyethyl acrylate copolymer and sodium hexametaphosphate, wherein the modified polyethylene terephthalate The content of ethylene glycol ester is 85% by weight, the content of polybutyl acrylate-hydroxyethyl acrylate copolymer is 10% by weight, and the content of dispersant is 5% by weight. Then it was heated and melted at 200°C, and electrospinning was performed on one surface of the PE base film, and dried at 60°C for 2 hours. After drying, it was spun on the other side in the same way...

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Abstract

The invention relates to the technical field of battery materials, and discloses a battery diaphragm, a preparation method thereof, a lithium ion battery and an electric vehicle. The battery diaphragmcomprises a polymer fiber layer, wherein the polymer fiber layer contains polymer fibers, the polymer fibers contain a cross-linked polymer, and the cross-linked polymer is obtained by cross-linkingmodified polyethylene glycol terephthalate and an acrylate polymer; the modified polyethylene glycol terephthalate contains hydroxyl and/or carboxyl, or the modified polyethylene glycol terephthalatehas carbon-carbon double bonds. The battery diaphragm provided by the invention has good thermal shrinkage resistance, more uniformly distributed pores and good air permeability, and can meet the safety and electrochemical performance requirements of a lithium battery.

Description

technical field [0001] The invention relates to the technical field of battery materials, in particular to a battery diaphragm, a method for preparing the battery diaphragm, a battery diaphragm prepared thereby, a lithium ion battery including the battery diaphragm, and an electric vehicle including the lithium ion battery. Background technique [0002] The main function of the separator is to separate the positive and negative electrodes of the battery to prevent short circuit caused by contact between the two electrodes. In addition, it also has the function of allowing electrolyte ions to pass through. Therefore, the performance of the battery separator directly affects the capacity, cycle and safety performance of the battery. , The separator with excellent performance plays an important role in improving the overall performance of the battery. [0003] CN20161006843A discloses a lithium-ion battery ceramic diaphragm slurry, specifically, the lithium-ion battery ceramic ...

Claims

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Application Information

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IPC IPC(8): H01M2/14H01M2/16H01M10/0525
CPCH01M10/0525H01M50/403H01M50/411H01M50/44Y02E60/10
Inventor 高磊刘荣华单军
Owner BYD CO LTD
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