Power lithium ion battery and composite diaphragm thereof

A technology of lithium-ion batteries and composite diaphragms, which is applied in the field of lithium-ion batteries and their composite diaphragms, power lithium-ion batteries and their polytetrafluoroethylene composite diaphragms, can solve the problems of large internal resistance and difficulty in assembling batteries, and reduce short circuits chance, anti-oxidation and reduction performance, and the effect of improving uniformity

Active Publication Date: 2012-10-24
CHINA HAISUM ENG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The porous polymer in the bonding layer must penetrate into the support layer and the polytetrafluoroethylene layer, and after curing, a "hinge" structure is formed between the support layer and the polytetrafluoroethylene layer, and the polytetrafluoroethylene composite membrane is not Indicated to be used for lithium-ion power battery separator, and not suitable for lithium-ion battery, because under the stated thickness, lithium-ion battery separator is thicker, it is difficult to assemble the battery and the internal resistance is larger

Method used

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  • Power lithium ion battery and composite diaphragm thereof
  • Power lithium ion battery and composite diaphragm thereof
  • Power lithium ion battery and composite diaphragm thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] 1. Preparation of composite separator S-1

[0041] The first step: add methyltriethoxysilane to ethanol solvent to make a dilute solution with a concentration of 0.5% (mass ratio), adjust the pH value of the solution to 3.5 with 5% hydrochloric acid, stir evenly, and spray on the thickness The surface of the polyester non-woven fabric with a porosity of 8 μm and a porosity of 70% was baked at 150° C. for 5 minutes to form a support layer of a cured adhesion aid;

[0042] The second step: adding 15g mass concentration of 5% hydrochloric acid and 20g epoxy silane into 160g ethanol, after stirring evenly, spraying on the surface of the polytetrafluoroethylene layer modified by plasma treatment, polytetrafluoroethylene The thickness is 3 μm, the porosity is 80%, and it is baked at 200 ° C for 2 minutes to form a polytetrafluoroethylene layer with a cured adhesion aid;

[0043] Step 3: Add 50 grams of N-methylpyrrolidone into the beaker, stir with a mechanical stirrer at a ...

Embodiment 2

[0049] 1. Preparation of composite separator S-2

[0050] The first step: add methyltriethoxysilane to ethanol solvent to make a dilute solution with a concentration of 2.0% (mass ratio), adjust the pH value of the solution to 4.0 with 5% hydrochloric acid, stir evenly, and spray on the thickness The surface of the polyester non-woven fabric with a porosity of 15 μm and a porosity of 70% was baked at 150° C. for 5 minutes to form a support layer of a cured adhesion aid;

[0051] The second step: adding 15g mass concentration of 5% hydrochloric acid and 20g epoxy silane into 160g ethanol, after stirring evenly, spraying on the surface of the polytetrafluoroethylene layer modified by plasma treatment, polytetrafluoroethylene The thickness is 10 μm, the porosity is 78%, and it is baked at 200 ° C for 2 minutes to form a polytetrafluoroethylene layer with a cured adhesion aid;

[0052] Step 3: Add 50 grams of N-methylpyrrolidone into the beaker, stir with a mechanical stirrer at ...

Embodiment 3

[0058] 1. Preparation of composite separator S-3

[0059] The first step: add methyltriethoxysilane to ethanol solvent to make a dilute solution with a concentration of 1.0% (mass ratio), adjust the pH value of the solution to 5.5 with 5% hydrochloric acid, stir well, and spray on the thickness The surface of the polyester non-woven fabric with a porosity of 10 μm and a porosity of 81% was baked at 150° C. for 5 minutes to form a support layer of a cured adhesion aid;

[0060] The second step: adding 15g mass concentration of 5% hydrochloric acid and 20g epoxy silane into 160g ethanol, after stirring evenly, spraying on the surface of the polytetrafluoroethylene layer modified by plasma treatment, polytetrafluoroethylene The thickness is 5 μm, the porosity is 88%, and it is baked at 200 ° C for 2 minutes to form a polytetrafluoroethylene layer with a cured adhesion aid;

[0061] Step 3: Add 50 grams of N-methylpyrrolidone into the beaker, stir with a mechanical stirrer at a s...

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Abstract

The invention discloses a composite diaphragm of a power lithium ion battery. The composite diaphragm comprises a supporting layer and an inorganic coating layer, and is characterized by further comprising a polytetrafluoroethylene layer, wherein the inorganic coating layer is coated on the supporting layer, the polytetrafluoroethylene layer is coated on the inorganic coating layer, and the surface and interior of the inorganic coating layer have porous interconnection structures. According to the composite diaphragm of the power lithium ion battery, organic/inorganic composite films are compounded with a polytetrafluoroethylene microporous film, and due to the existence of the polytetrafluoroethylene microporous film, in the process of manufacturing the composite diaphragm of the power lithium ion battery and in the process of manufacturing a wound electrode group of the battery, the inorganic coating layer has good adhesive property on the composite diaphragm and is difficult to fall off; and the composite diaphragm has the advantages of high tearing strength, perforation resistant strength, high-temperature and low temperature resistance, high corrosion resistance, electrical insulating property and chemical stability, and particularly the high oxidation-reduction resistance of polytetrafluoroethylene has more superiority for prolonging the service life of the lithium ion battery and improving the use safety of the lithium ion battery.

Description

technical field [0001] The invention relates to a lithium ion battery and a composite diaphragm thereof, in particular to a power lithium ion battery and a polytetrafluoroethylene composite diaphragm thereof, and belongs to the technical field of lithium electronic battery manufacturing. Background technique [0002] Separator is an important component material of power lithium-ion battery, usually a thin porous insulating material with high ion permeability and mechanical strength, and long-term stability to various chemical substances and chemical solvents. The separator separates the positive and negative electrodes of the battery to prevent the short circuit caused by contact between the two electrodes; at the same time, relying on the microporous structure of the separator itself, it allows ions to pass through easily and maintains good ionic conductivity between the positive and negative electrodes. [0003] When the power lithium-ion battery is used as a high-power po...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16H01M10/0525B32B27/32B32B5/30
CPCY02E60/122Y02E60/10
Inventor 刘攀吴立群
Owner CHINA HAISUM ENG
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