Unlock instant, AI-driven research and patent intelligence for your innovation.

A lithium battery diaphragm and preparation method thereof

A lithium battery diaphragm and polyethylene technology, applied in battery pack parts, circuits, electrical components, etc., can solve the problems of closed pores and membrane rupture of the diaphragm, and achieve the effect of preventing short-circuit accidents, improving strength, and ensuring integrity.

Active Publication Date: 2021-08-24
JIESHOU CITY TIANHONG PACKAGING MATERIAL
View PDF13 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a lithium battery separator, which is a single-layer composite system, which overcomes the problem that the closed cell temperature of the single-layer material separator in the prior art is the same as the melting temperature. When the diaphragm is closed, it is easy to cause the problem of membrane rupture

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A lithium battery diaphragm and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] A lithium battery diaphragm, the lithium battery diaphragm includes 95.05% polyethylene, 4.5% polybutylene terephthalate, 0.45% compatibilizer SEBS-g-MA, the percentage is mass percent ;

[0035] The preparation method of the above-mentioned lithium battery diaphragm includes weighing the raw materials according to the formula, passing through a dry mixing device, melting and mixing through an extruder, casting and extruding from a die head after being pressurized by a melt pump, cooling the cast sheet, and then passing through a longitudinal Stretching, transverse stretching, and heat setting treatment to form the lithium battery separator;

[0036] The conditions for longitudinal stretching include: the stretching temperature is 135°C, and the stretching ratio is 3.35;

[0037] The conditions for the transverse stretching include: the stretching temperature is 135°C, and the stretching ratio is 3.4;

[0038] The conditions of the heat setting treatment include: the ...

Embodiment 2

[0040]Like the lithium battery separator provided in Example 1, the difference is that the compatibilizer contained in the lithium battery separator is SEBS, and the rest remains unchanged, and the lithium battery separator is prepared according to the method in Example 1.

Embodiment 3

[0042] Like the lithium battery separator provided in Example 1, the difference is that the compatibilizer contained in the lithium battery separator is SEBS-g-GMA, and the rest remains unchanged, and the lithium battery separator is prepared according to the method in Example 1.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
stretch ratioaaaaaaaaaa
stretch ratioaaaaaaaaaa
Login to View More

Abstract

The invention belongs to the technical field of lithium battery separators, in particular to a lithium battery separator and a preparation method thereof, wherein the lithium battery separator includes polyethylene doped with polybutylene terephthalate and a compatibilizer; the lithium The battery separator includes 93.4-97.25% of polyethylene, 2.5-6% of polybutylene terephthalate, and 0.25-0.6% of compatibilizer, and the percentage is by mass; the lithium battery provided by the invention The separator is a single-layer composite system. By mixing polybutylene terephthalate into polyethylene, the incompatible characteristics of the two are used to form a microporous structure during the biaxial stretching process. When the temperature is high, the polyethylene melts to form a closed cell of the diaphragm, and the polybutylene terephthalate provides a fulcrum to ensure the integrity of the diaphragm and effectively prevent the short-circuit accident caused by the contact between the positive and negative electrodes inside the battery. Occurs; the lithium battery separator formed after biaxial stretching has good strength in both longitudinal and transverse directions.

Description

technical field [0001] The invention belongs to the technical field of lithium battery diaphragms, and in particular relates to a lithium battery diaphragm and a preparation method thereof. Background technique [0002] The lithium battery diaphragm is one of the key inner components of the lithium battery. Its main function is to separate the positive and negative electrodes of the lithium battery to prevent the two poles from contacting and short-circuiting; although the material of the lithium battery diaphragm is non-conductive, it has The function of allowing electrolyte ions to pass through; the performance of the separator determines the interface structure and internal resistance of the lithium battery, which directly affects the capacity, cycle and safety performance of the lithium battery. Under overcharge / overdischarge or other extreme conditions, the internal temperature of the lithium battery will rise rapidly. When the internal temperature of the lithium batter...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H01M50/417H01M50/403H01M50/406
CPCY02E60/10
Inventor 胡伟吴磊张德顺李汪洋何祥燕徐凤锦孙小华郭浩贺云杨建军
Owner JIESHOU CITY TIANHONG PACKAGING MATERIAL