Lithium battery diaphragm with high thermostability and preparation method thereof

A lithium battery diaphragm, high thermal stability technology, applied in battery pack parts, circuits, electrical components, etc., can solve the problems of battery combustion and explosion, diaphragm size shrinkage, holes, etc., to avoid falling off, avoid short circuits, and improve thermal The effect of stability

Active Publication Date: 2019-03-01
广东永邦新能源股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The currently marketed lithium-ion battery separators are mainly polyolefin (mainly PE, PP) microporous membranes. The melting point of the main material of the polyolefin separator is relatively low, about 130°C to 165°C. When the battery is heated to the melting point of the separator material When the temperature is near, the diaphragm will have obvious size shrinkage, resulting in holes, resulting in a short circuit caused by contact between the positive and negative electrodes, which will cause the battery to burn and explode.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] A lithium battery separator with high thermal stability, the lithium battery separator is composed of a polyimide nuclear pore membrane, a ceramic layer and an electrospun nanofiber layer, and the thickness of the lithium battery separator is 50 μm.

[0028] The thickness ratio of polyimide nuclear pore membrane:ceramic layer:electrospun nanofiber layer is 5:2:3.

[0029] A lithium battery diaphragm with high thermal stability, its preparation method comprises the following steps:

[0030] a. Preparation of polyimide nuclear pore membrane

[0031] At 70°C, put the polyimide film into the sodium hydroxide etching solution for immersion. After soaking for 35 minutes, take out the polyimide film, wash it with deionized water, and dry it to obtain polyimide core pores. membrane;

[0032] b. Preparation of ceramic layer

[0033] 30 parts of porous alumina, 0.9 parts of dispersant, 0.3 parts of suspension stabilizer and 1.2 parts of surfactant were added to 60 parts of dei...

Embodiment 2

[0044] A lithium battery diaphragm with high thermal stability, the lithium battery diaphragm is composed of a polyimide nuclear pore membrane, a ceramic layer and an electrospun nanofiber layer, and the thickness of the lithium battery diaphragm is 65 μm.

[0045] The two planes of the lithium battery diaphragm are respectively coated with a conductive coating, the thickness of the conductive coating is 2 μm, and the slurry of the conductive coating measures the following components by weight percentage, binder 8%, dispersant 2%, 85% solvent and carbon material 5, the carbon material is carbon tube and flake graphite with a weight ratio of 1:1, and the binder is hydroxypropyl methylcellulose with a weight ratio of 1:1:1, Styrene-butadiene rubber latex, polyethylene oxide; the dispersant is modified polyoxyethylene ether and polyvinylpyrrolidone with a weight ratio of 1:1; the solvent is water.

[0046] The thickness ratio of polyimide nuclear pore membrane:ceramic layer:elect...

Embodiment 3

[0062] A lithium battery separator with high thermal stability, the lithium battery separator is composed of a polyimide nuclear pore membrane, a ceramic layer and an electrospun nanofiber layer, and the thickness of the lithium battery separator is 70 μm.

[0063] The two planes of the lithium battery diaphragm are respectively coated with a conductive coating, the thickness of the conductive coating is 5 μm, and the slurry of the conductive coating measures the following components by weight percentage, binder 5%, dispersant 3%, 82% solvent and 10% carbon material, the carbon material is carbon tube and flake graphite with a weight ratio of 1:5, and the binder is hydroxypropyl methylcellulose with a weight ratio of 2:3:5 , styrene-butadiene rubber latex, polyethylene oxide; the dispersant is modified polyoxyethylene ether and polyvinylpyrrolidone with a weight ratio of 1:5; the solvent is water.

[0064] The thickness ratio of polyimide nuclear pore membrane:ceramic layer:el...

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Abstract

The invention relates to the technical field of lithium batteries, in particular to a lithium battery diaphragm with high thermostability and a preparation method thereof. The lithium battery diaphragm is composed of a polyimide nucleopore membrane, a ceramic layer and an electrostatic spinning nanofiber layer, polyimide with high heat resistance performance and high insulating performance is taken as a base membrane, and the base membrane is successively coated with the ceramic layer and the electrostatic spinning nanofiber layer; porous aluminium oxide in the ceramic layer has better heat conduction performance, heat on the diaphragm can be timely conducted, and it is avoided that the short circuit phenomenon occurs due to excess local thermal contraction; the electrostatic spinning nanofiber layer not only can improve the evenness of the diameter of holes in the surface of the diaphragm and improve the thermostability of the lithium battery diaphragm, but also can be closely combined with the ceramic layer to avoid falling of the porous aluminium oxide in the ceramic layer; the lithium battery diaphragm prepared by adopting the method has the advantages that the thermostabilityis good, and the heat conduction effect is excellent.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a lithium battery diaphragm with high thermal stability and a preparation method thereof. Background technique [0002] In the structure of lithium batteries, the separator is one of the key inner components. The performance of the separator determines the interface structure and internal resistance of the battery, which directly affects the capacity, cycle and safety performance of the battery. A separator with excellent performance plays an important role in improving the overall performance of the battery. The main function of the diaphragm is to separate the positive and negative electrodes of the battery, prevent the two electrodes from contacting and short circuit, and also have the function of allowing electrolyte ions to pass through. The separator material is non-conductive, and its physical and chemical properties have a great influence on the performance of ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16H01M2/14H01M50/403H01M50/417H01M50/423H01M50/434H01M50/44H01M50/489H01M50/491
CPCH01M50/431H01M50/411H01M50/44H01M50/403H01M50/449Y02E60/10
Inventor 姚学永唐忠荣冷佩佩
Owner 广东永邦新能源股份有限公司
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