Battery diaphragm, preparation method thereof, and impregnation equipment of polyimide porous membrane

A polyimide-based film, polyimide technology, applied in battery pack parts, circuits, electrical components, etc., can solve the problems of diaphragm piercing assembly strength, burning diaphragm, diaphragm melting, etc. Wetting ability and liquid retention performance, improving ionic conductivity, and avoiding the effect of poor air permeability

Active Publication Date: 2021-05-14
SHANDONG RES & DESIGN ACADEMY OF IND CERAMICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When the internal temperature of the lithium-ion battery is out of control due to short circuit, overcharge, etc., the higher temperature will close the pores of the polymer diaphragm and interrupt the current. However, when the temperature continues to rise and exceeds the heat-resistant temperature of the diaphragm, The separator may be melted, causing the battery to short circuit, resulting in a battery safety accident
[0003] At present, the commercialized separator is mainly polyolefin microporous membrane, which has the advantages of excellent mechanical properties and uniform pore size, but its melting temperature is lower than 165°C. When the external temperature of the battery is too high or it is accidentally hit, the separator will melt and cause security incident
It is necessary to find a diaphragm with higher heat resistance temperature. In the prior art, there is a plan to use polyimide diaphragm instead of polyolefin microporous membrane, but compared with polyolefin diaphragm, polyimide diaphragm has no closed-cell performance, If there is a problem with the battery, a large amount of heat will be released, which may burn out the diaphragm in an instant; the diaphragm is easy to be pierced and the assembly strength is low. In addition, when the external temperature of the battery is too high or it is accidentally hit, it is easy to cause a short circuit of the battery, resulting in a battery safety accident. security performance is threatened

Method used

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  • Battery diaphragm, preparation method thereof, and impregnation equipment of polyimide porous membrane
  • Battery diaphragm, preparation method thereof, and impregnation equipment of polyimide porous membrane
  • Battery diaphragm, preparation method thereof, and impregnation equipment of polyimide porous membrane

Examples

Experimental program
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Embodiment 1

[0046] This embodiment provides a battery separator, comprising a polyolefin porous film layer and a polyimide porous film layer,

[0047] The polyimide porous film layer comprises a polyimide base film and an impregnation layer coated on the outside of the polyimide base film, and the impregnation layer comprises a polyimide resin or a phenolic resin or an aramid resin and the like. High-temperature reinforced resin, the high-temperature-resistant reinforced resin refers to a resin whose temperature resistance is greater than 280°C. The piercing strength of the polyimide porous film layer is 0.68-3N, and the MD direction tensile strength of the porous diaphragm is greater than twice that of the polyimide base film. In this embodiment, the polyimide The MD direction tensile strength of the porous film layer is greater than 70MPa, the TD direction tensile strength of the porous diaphragm is greater than 50MPa, and the air permeability of the polyimide porous film layer is 30-12...

Embodiment 2

[0067] This embodiment provides a battery separator, comprising a polyolefin porous film layer and a polyimide porous film layer, the polyimide porous film layer comprising a polyimide base film and a polyimide base film coated The outer impregnation layer, the impregnation layer includes polyimide resin, phenolic resin or aramid resin and other high temperature resistant reinforced resin, the high temperature resistant reinforced resin refers to a resin with a temperature resistance greater than 280°C. The piercing strength of the polyimide porous membrane layer is 0.68N, and the tensile strength of the porous diaphragm in the MD direction is greater than twice that of the polyimide base membrane.

[0068] It also includes an aluminum oxide coating and an adhesive layer between the polyimide porous film layer and the polyolefin porous film layer, and the polyolefin porous film layer and the polyimide porous film layer pass through the aluminum oxide coating, The adhesive laye...

Embodiment 3

[0076] This embodiment provides a battery separator, comprising a polyolefin porous film layer and a polyimide porous film layer, the polyimide porous film layer comprising a polyimide base film and a polyimide base film coated The outer impregnation layer, the impregnation layer includes polyimide resin, phenolic resin or aramid resin and other high temperature resistant reinforced resin, the high temperature resistant reinforced resin refers to a resin with a temperature resistance greater than 280°C. The piercing strength of the polyimide porous membrane layer is 2.4N, and the tensile strength of the porous diaphragm in the MD direction is greater than twice that of the polyimide base membrane.

[0077] It also includes an aluminum oxide coating and an adhesive layer between the polyimide porous film layer and the polyolefin porous film layer, and the polyolefin porous film layer and the polyimide porous film layer pass through the aluminum oxide coating, The adhesive layer...

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Abstract

The invention discloses a battery diaphragm. The battery diaphragm comprises a polyolefin porous membrane layer and a polyimide porous membrane layer, the polyimide porous membrane layer is an impregnated polyimide base membrane, the puncture strength of the polyimide porous membrane layer is 0.68-3 N, and the tensile strength of the porous diaphragm in the MD direction is two times greater than that of the polyimide base membrane; and thebattery diaphragm further includes analuminum oxide coating and an adhesive layer which are located between the polyimide porous membrane layer and the polyolefin porous membrane layer, and the polyolefin porous membrane layer and the polyimide porous membrane layer are compounded through the aluminum oxide coating and the adhesive layer.

Description

technical field [0001] The invention relates to the technical field of composite materials, in particular to a battery separator, a preparation method and an impregnation device for a polyimide porous membrane. Background technique [0002] Separators play a crucial role in the safety of lithium-ion secondary batteries. When the internal temperature of the lithium-ion battery is out of control due to short circuit, overcharge, etc., the higher temperature will close the pores of the polymer diaphragm and interrupt the current. However, when the temperature continues to rise and exceeds the heat-resistant temperature of the diaphragm, The separator may be melted, causing the battery to short circuit, resulting in a battery safety accident. [0003] At present, the commercialized separator is mainly polyolefin microporous membrane, which has the advantages of excellent mechanical properties and uniform pore size, but its melting temperature is lower than 165°C. When the exter...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M50/417H01M50/423H01M50/449H01M50/403B05B13/02B05C3/132B05C11/02
CPCB05B13/0278B05B13/0221B05C3/132B05C11/025Y02E60/10
Inventor 李茹齐学礼张铭霞周长灵聂永俊何子阳孙淑敏岳双双
Owner SHANDONG RES & DESIGN ACADEMY OF IND CERAMICS
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