Mixed coating lithium battery diaphragm and preparation method thereof

A lithium battery diaphragm and coating technology, which is applied in the direction of secondary batteries, battery pack components, circuits, etc., to achieve the effects of favorable battery capacity retention, easy absorption, and good air permeability

Pending Publication Date: 2020-05-08
高芳
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, with the development of lithium batteries, the requirements for the adhesion of the diaphragm are getting higher and higher, and the pure PVDF coating cannot meet the corresponding requirements.

Method used

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  • Mixed coating lithium battery diaphragm and preparation method thereof
  • Mixed coating lithium battery diaphragm and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Such as figure 1 Shown, a kind of lithium battery diaphragm of mixed coating, base film 1 and the coating layer 2 that is coated on one side of base film constitute, the upper surface of coating layer is coated with the coating layer 3 of PMMA / PVDF, described The thickness of the coating layer 2 is 1-2um, and the thickness of the coating layer 3 of the PMMA / PVDF is 0.3-1.8um;

[0032] The coating layer 2 is composed of the following parts by mass: 20 parts of alumina micropowder, 40 parts of aluminum hydroxide micropowder, 2 parts of adhesive, 1 part of cosolvent, 1 part of emulsifier, 2 parts of pore forming agent, 0.5 parts of ethylene oxide dispersant and 20 parts of water;

[0033] The coating layer 3 of PMMA / PVDF consists of the following parts by mass: 20 parts of ceramic powder, 20 parts of PVDF powder, 20 parts of PMMA powder, 1 part of coupling agent, 2 parts of dispersant, 5 parts of wetting agent, 2 parts of defoamer, 2 parts of co-solvent, 1 part of emulsi...

Embodiment 2

[0041] Such as figure 1 Shown, a kind of lithium battery diaphragm of mixed coating, base film 1 and the coating layer 2 that is coated on one side of base film constitute, the upper surface of coating layer is coated with the coating layer 3 of PMMA / PVDF, described The thickness of the coating layer 2 is 1-2um, and the thickness of the coating layer 3 of the PMMA / PVDF is 0.3-1.8um;

[0042] The coating layer 2 is composed of the following parts by mass: 22 parts of alumina micropowder, 45 parts of aluminum hydroxide micropowder, 3 parts of adhesive, 2 parts of cosolvent, 1.5 parts of emulsifier, 4 parts of pore-forming agent, poly 1 part of ethylene oxide dispersant and 22 parts of water;

[0043] The coating layer 3 of PMMA / PVDF consists of the following parts by mass: 25 parts of ceramic powder, 22 parts of PVDF powder, 22 parts of PMMA powder, 1.3 parts of coupling agent, 4 parts of dispersant, 6 parts of wetting agent, 3 parts of defoamer, 3 parts of co-solvent, 1.2 parts...

Embodiment 3

[0051] Such as figure 1 Shown, a kind of lithium battery diaphragm of mixed coating, base film 1 and the coating layer 2 that is coated on one side of base film constitute, the upper surface of coating layer is coated with the coating layer 3 of PMMA / PVDF, described The thickness of the coating layer 2 is 1-2um, and the thickness of the coating layer 3 of the PMMA / PVDF is 0.3-1.8um;

[0052] The coating layer 2 is composed of the following parts by mass: 25 parts of alumina micropowder, 50 parts of aluminum hydroxide micropowder, 3 parts of adhesive, 2 parts of cosolvent, 2 parts of emulsifier, 4 parts of pore-forming agent, poly 1 part of ethylene oxide dispersant and 25 parts of water;

[0053] The coating layer 3 of PMMA / PVDF consists of the following parts by mass: 30 parts of ceramic powder, 25 parts of PVDF powder, 25 parts of PMMA powder, 107 parts of coupling agent, 6 parts of dispersant, 7 parts of wetting agent, 4 parts of defoamer, 4 parts of co-solvent, 1.6 parts...

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Abstract

The invention provides a lithium ion battery composite diaphragm and a preparation method thereof, relating to the technical field of batteries. The lithium ion battery composite diaphragm comprises abase film and an aramid fiber coating and the water-based PVDF composite coating which coat one side of the base film; the water-based PVDF composite coating is prepared from, by weight, 1-10% of a base material and the balance of deionized water, and the base material is prepared from PVDF, a dispersing agent, a thickening agent, an adhesive, nano aramid fiber powder, DMAC or DMF, a cosolvent, an emulsifying agent and a pore forming agent. Compared with the prior art, the aramid fiber coating diaphragm disclosed by the invention has better heat resistance, stability, electrical insulating property and flame retardant property on the whole; the PVDF coating is obtained by coating and drying water-based PVDF slurry, the traditional process that acetone and other oily substances serve as solvents of an existing PVDF-coated lithium ion battery diaphragm is abandoned, and the safety performance, the rate capability and the cycle performance of a lithium ion battery prepared from the diaphragm are obviously improved.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a mixed-coated lithium battery diaphragm and a preparation method thereof. Background technique [0002] As a new type of secondary battery, lithium battery has the advantages of high energy density and long cycle life. Its application range continues to expand and is widely used in portable electronic devices, electric tools, energy storage and power vehicles. With the rapid development, lithium batteries are more and more used in power vehicles. As an important part of the lithium battery, the diaphragm can effectively prevent the short circuit of the positive and negative electrodes, which has a very important impact on the safety of the lithium battery. Therefore, the improvement of the performance of the lithium battery and the safety requirements have a higher performance of the diaphragm. Require. [0003] Polyolefin separators are currently the most widely used sepa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/14H01M2/16H01M10/0525
CPCH01M10/0525H01M50/403H01M50/411H01M50/44Y02E60/10
Inventor 高保清舒均国陈立新高芳
Owner 高芳
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