Polyester porous diaphragm for secondary lithium battery and preparation method of polyester porous diaphragm

A technology of secondary lithium battery and microporous separator, which is applied in battery pack parts, circuits, electrical components, etc., can solve the problems of decreased air permeability and high thermal shrinkage rate, and achieves low high temperature thermal shrinkage rate, simple production process, good performance

Active Publication Date: 2014-04-16
四川东方绝缘材料股份有限公司
View PDF2 Cites 22 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The present invention aims at the shortcomings of existing polyolefin separators such as high thermal shrinkage rate and decreased air permeability at temperatures above 160°C, and provides a single-layer polyester material

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
  • Polyester porous diaphragm for secondary lithium battery and preparation method of polyester porous diaphragm
  • Polyester porous diaphragm for secondary lithium battery and preparation method of polyester porous diaphragm
  • Polyester porous diaphragm for secondary lithium battery and preparation method of polyester porous diaphragm

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1-1、1-2

[0033] After drying the components with a certain proportion in Table 1 under different conditions, the twin-screw extruder was melted and kneaded at 280°C and then extruded and cut into granules, and the obtained granules were dried again to After the moisture content is 200ppm, put it into a single-screw extruder to melt, knead and extrude it at 280°C, cool it with a cold drum at 20°C-40°C and cast it into a thick sheet with a thickness of 0.2-0.3mm. After stretching 2 times in the longitudinal direction at 135°C, preheat in the drying tunnel at 135°C, perform simultaneous biaxial stretching at 135°C, stretch 2 times in the longitudinal direction and 2.5 times in the transverse direction, and then heat-setting at 135°C , to obtain a polyester microporous separator.

Embodiment 2-1、2-2

[0035] After drying the components with a certain proportion in Table 1 under different conditions, the twin-screw extruder melted and kneaded at 275 ° C and then extruded and cut into granules, and the obtained granules were dried again to After the moisture content is 200ppm, put it into a single-screw extruder to melt, knead and extrude it at 275°C, then cool it with a cold drum at 20°C to 40°C and cast it into a thick sheet with a thickness of 0.2 to 0.3mm. After stretching 2 times in the longitudinal direction at low temperature, it is preheated through the drying tunnel at 110°C, and then the biaxial stretching is carried out simultaneously at 110°C, stretching 2 times in the longitudinal direction and 3 times in the transverse direction, and then heat-setting at 145°C. A polyester microporous separator was obtained.

Embodiment 3-1、3-2

[0037] After drying the various components with a certain proportion and number given in Table 1 under different conditions, the twin-screw extruder melted and kneaded at 285 ° C and then extruded and cut into granules, and the obtained granules were dried again to After the moisture content is 200ppm, put it into a single-screw extruder to melt, knead and extrude at 285°C, cool it with a cold drum at 20°C to 40°C and cast it into a thick sheet with a thickness of 0.2 to 0.3mm. After stretching 2 times in the longitudinal direction at 115°C, preheat the drying tunnel at 115°C, perform simultaneous biaxial stretching at 115°C, stretch 2 times in the longitudinal direction and 2.8 times in the transverse direction, and then heat-setting at 150°C. A polyester microporous separator was obtained.

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
Thicknessaaaaaaaaaa
Melt indexaaaaaaaaaa
Densityaaaaaaaaaa
Login to view more

Abstract

The invention discloses a polyester porous diaphragm for a secondary lithium battery. The polyester porous diaphragm is characterized by consisting of the following components in percentage by mass: 40-79 percent of polymer A, 15-30 percent of polymer B, 5-15 percent of a compatilizer and 1-15 percent of a pore-forming agent, wherein the thickness of the diaphragm is 0.01-0.05mm. The method for preparing the diaphragm comprises the following steps: uniformly mixing the polymer A, the polymer B, the compatilizer and the pore-forming agent, melting, mixing and granulating through a double-screw extruder, drying, performing melt extrusion through a single screw extruder, performing cold blast casting, longitudinally stretching for 2-8 times at the temperature of 80-150 DEG C, synchronously and longitudinally stretching for 2-6 times and transversely stretching for 1.5-8 times at the temperature of 80-150 DEG C, performing heat setting treatment, and preparing the polyester porous diaphragm. The polyester porous diaphragm has excellent mechanical strength, heat shrinkable property and closure characteristics, can be used for production and manufacture of the secondary lithium battery and is particularly suitable for the secondary lithium battery which works at the temperature of over 160 DEG C.

Description

technical field [0001] The invention belongs to a diaphragm for lithium batteries and its preparation, and relates to a polyester microporous diaphragm for a secondary lithium battery and a preparation method thereof. The polyester microporous diaphragm of the invention is suitable for the production and manufacture of secondary lithium batteries, and is particularly suitable as the polyester microporous diaphragm for secondary lithium batteries working at a temperature above 160°C. Background technique [0002] In the prior art, the separator materials used in lithium batteries mainly include polypropylene, polyethylene, polyimide, and polyvinylidene fluoride, which are generally single-layer or multi-layer films, and the process methods mainly adopt dry method and Two types of wet method. The shut-off temperature of single-layer or multi-layer separators of polypropylene and polyethylene materials using dry process is 130 ° C ~ 160 ° C, it is difficult to ensure the safet...

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
IPC IPC(8): C08L67/02C08L77/06C08L69/00C08L77/02C08L23/20C08L51/06C08K3/36B29C69/00B29C39/14B29C39/44B29C55/02H01M2/16H01M50/403H01M50/417H01M50/489
CPCY02E60/10
Inventor 赵贵红马雅琳胡俊祥罗春明李建学
Owner 四川东方绝缘材料股份有限公司
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