Composite diaphragm for lithium batteries and preparation method of composite diaphragm for lithium batteries

A composite diaphragm, lithium battery technology, applied in battery pack parts, chemical instruments and methods, applications, etc., can solve the problems of difficult to control pore size, large environmental pollution, complex process, etc., and achieve good mechanical performance and good continuity. , the effect of good safety performance

Active Publication Date: 2018-05-15
新纶新能源材料(常州)有限公司
View PDF6 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the wet production of microporous membranes, the pore size and porosity are easier to control, and the tortuosity of the pores is relatively high, but a large amount of solvent is required, the process is complicated, and the environmental pollution is large; the proce

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] This embodiment provides a composite separator for a lithium battery, which has a three-layer structure, the surface layers on both sides are high-strength polypropylene microporous membranes, and the core layer is a low-melting point self-shutoff polyethylene microporous membrane;

[0037] The raw material of the high-strength polypropylene microporous membrane is polypropylene resin with a molecular weight of 300,000-1,000,000, a molecular weight distribution index Mw / Mn of 4-8, an isotacticity>96%, and a melt flow rate of 1.3-3.3;

[0038] The raw material of the low-melting point self-shutoff polyethylene microporous membrane is high-density polyethylene, the molecular weight is 100,000-300,000, the molecular weight distribution index Mw / Mn is 4-8, and the melt flow rate is 0.2-0.8.

[0039] This embodiment also provides the preparation method of the above-mentioned composite diaphragm for lithium battery, comprising the following steps:

[0040] The polypropylene r...

Embodiment 2

[0050] This embodiment provides a composite separator for a lithium battery, which has a three-layer structure, the surface layers on both sides are high-strength polypropylene microporous membranes, and the core layer is a low-melting point self-shutoff polyethylene microporous membrane;

[0051] The raw material of the high-strength polypropylene microporous membrane is polypropylene resin with a molecular weight of 300,000-1,000,000, a molecular weight distribution index Mw / Mn of 4-8, an isotacticity>96%, and a melt flow rate of 1.3-3.3;

[0052] The raw material of the low-melting point self-shutoff polyethylene microporous membrane is high-density polyethylene, the molecular weight is 100,000-300,000, the molecular weight distribution index Mw / Mn is 4-8, and the melt flow rate is 0.2-0.8.

[0053] This embodiment also provides the preparation method of the above-mentioned composite diaphragm for lithium battery, comprising the following steps:

[0054] The polypropylene r...

Embodiment 3

[0064] This embodiment provides a composite separator for a lithium battery, which has a three-layer structure, the surface layers on both sides are high-strength polypropylene microporous membranes, and the core layer is a low-melting point self-shutoff polyethylene microporous membrane;

[0065] The raw material of the high-strength polypropylene microporous membrane is polypropylene resin with a molecular weight of 300,000-1,000,000, a molecular weight distribution index Mw / Mn of 4-8, an isotacticity>96%, and a melt flow rate of 1.3-3.3;

[0066] The raw material of the low-melting point self-shutoff polyethylene microporous membrane is high-density polyethylene, the molecular weight is 100,000-300,000, the molecular weight distribution index Mw / Mn is 4-8, and the melt flow rate is 0.2-0.8.

[0067] This embodiment also provides the preparation method of the above-mentioned composite diaphragm for lithium battery, comprising the following steps:

[0068] The polypropylene r...

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
Thicknessaaaaaaaaaa
Apertureaaaaaaaaaa
Login to view more

Abstract

The invention provides a composite diaphragm for lithium batteries. The composite diaphragm is in a three-layer structure, two side surface layers are high-strength polypropylene microporous membranes, and a core layer is a low-melting-point self-turn-off polyethylene microporous membrane. The high-strength polypropylene microporous membranes are made from polypropylene resin, wherein the molecular weight is 300000-1000000, a molecular weight distribution index Mw/Mn is 4-8, isotacticity is larger than 96%, and the melt flow rate is 1.3-3.3. The low-melting-point self-turn-off polyethylene microporous membrane is made from high-density polyethylene, wherein the molecular weight is 100000-300000, a molecular weight distribution index Mw/Mn is 4-8, and the melt flow rate is 0.2-0.8. The composite diaphragm for the lithium batteries is low in pore closing temperature, high in membrane rupture temperature, wide in self-turn-off safety window, great in mechanical performance, high in puncture strength, high in safety in lithium ion battery production and utilization processes, appropriate in microporous diameter size, uniform in distribution and high in connectivity, the batteries are low in internal resistance, and improvement of operating efficiency of the batteries is benefited.

Description

technical field [0001] The invention relates to a composite separator for lithium batteries and a preparation method thereof, belonging to the technical field of lithium batteries. Background technique [0002] Lithium-ion battery separator is an important component in lithium-ion batteries. It is a thin film material with nano-scale pores, which plays a role in blocking the positive and negative electrodes in the battery and preventing the internal short circuit of the battery; at the same time, it must allow ions The current passes quickly to ensure the rapid transmission of lithium ions between the positive and negative electrodes during battery charging and discharging. The microporous structure, physical properties, chemical properties, and thermal properties of the separator determine the interface structure and internal resistance of the battery, which directly affect the capacity, cycle performance, and safety performance of the battery. A separator with excellent pe...

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): H01M2/16H01M2/14B32B27/08B32B27/32B32B3/24B29C47/06B29C47/56B29C47/92B29C55/04B29C69/02B29C71/02B29L7/00B29L9/00B29C48/92H01M50/403H01M50/411H01M50/457H01M50/491
CPCB29C48/0018B29C48/18B29C48/49B29C48/92B29C55/04B29C71/02B32B3/266B32B27/08B32B27/32B29L2007/00B29L2009/00B32B2457/10B32B2307/558B29C2948/92704B29C2948/92904H01M50/403H01M50/411H01M50/449Y02E60/10
Inventor 杨茜
Owner 新纶新能源材料(常州)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