Battery separator with Z-direction stability

a battery separator and z-direction technology, applied in the manufacture of final products, cell components, cell component details, etc., can solve the problems of increasing the risk of physical contact, increasing the temperature of the battery, and nothing being done to improve the z-direction dimensional stability of the battery separator

Inactive Publication Date: 2006-04-27
CELGARD LLC
View PDF2 Cites 17 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Increasing temperature in the battery may be caused by internal shorting, i.e., physical contact of the anode and cathode.
The physical contact may be caused by, for example, physical damage to the battery, damage to the separator during battery manufacture, dendrite growth, excessive charging, and the like.
To date, nothing has been done to improve the Z-direction dimensional stability of these battery separators.
As they move closer to one another, the risk of physical contact increases.

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
  • Battery separator with Z-direction stability

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0011] A battery separator, as used herein, refers to a thin, microporous membrane that is placed between the electrodes of a battery. It physically separates the electrodes to prevent their contact, allows ions to pass through the pores between the electrodes during discharging and charging, acts as a reservoir for the electrolyte, and may have a ‘shut down’ function. Hereinafter, discussion of the battery separator shall be made with reference to lithium-ion batteries, it being understood, however, that the separator is not so limited.

[0012] Microporous membranes typically have porosities in the range of 20-80%, alternatively in the range of 28-60%. The average pores size is in the range of 0.02 to 2.0 microns, alternatively in the range of 0.04 to 0.25 microns. The membrane has a Gurley Number in the range of 5 to 150 sec, alternatively 20 to 80 sec (Gurley Numbers refers to the time it takes for 10 cc of air at 12.2 inches of water to pass through one square inch of membrane). ...

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
temperatureaaaaaaaaaa
temperatureaaaaaaaaaa
thicknessaaaaaaaaaa
Login to view more

Abstract

A battery separator is a microporous membrane. The membrane has a major volume of a thermoplastic polymer and a minor volume of an inert particulate filler. The filler is dispersed throughout the polymer. The membrane exhibits a maximum Z-direction compression of 95% of the original membrane thickness. Alternatively, the battery separator is a microporous membrane having a TMA compression curve with a first substantially horizontal slope between ambient temperature and 125° C., a second substantially horizontal slope at greater than 225° C. The curve of the first slope has a lower % compression than the curve of the second slope. The curve of the second slope is not less than 5% compression. The TMA compression curve is graphed so that the Y-axis represents % compression from original thickness and the X-axis represents temperature.

Description

BACKGROUND OF THE INVENTION [0001] The use of microporous membranes as battery separators is known. For example, microporous membranes are used as battery separators in lithium-ion batteries. Such separators may be single layered or multi-layered thin films made of polyolefins. These separators often have a ‘shut-down’ property such that when the temperature of the battery reaches a predetermined temperature, the pores of the membrane close and thereby prevent the flow of ions between the electrodes of the battery. Increasing temperature in the battery may be caused by internal shorting, i.e., physical contact of the anode and cathode. The physical contact may be caused by, for example, physical damage to the battery, damage to the separator during battery manufacture, dendrite growth, excessive charging, and the like. As such, the separator, a thin (e.g., typically about 8-25 microns thickness) microporous membrane, must have good dimensional stability. [0002] Dimensional stability...

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 Applications(United States)
IPC IPC(8): H01M2/16
CPCH01M2/166H01M2/18H01M50/446Y02E60/10H01M50/443H01M50/491H01M50/414H01M10/0525H01M4/382H01M10/4235H01M50/581H01M50/431H01M50/463Y02P70/50
Inventor ARORA, PANKAJCALL, RONALD W.DAO, TIENNGUYEN, KHUY V.SIMMONS, DONALD K.ZHANG, ZHENGMING
Owner CELGARD LLC
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap