Polypropylene/polyethylene/polypropylene three-layer co-extruded lithium-ion battery separator and preparation method thereof

A lithium-ion battery, three-layer co-extrusion technology, used in secondary batteries, battery pack parts, circuits, etc., can solve problems such as affecting the stability of the diaphragm, achieve good strength, good surface plasticization uniformity, improve integrity effect on sex and battery safety

Active Publication Date: 2017-11-07
HUIQIANG WUHAN NEW ENERGY MATERIAL TECH
View PDF10 Cites 29 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the above patents, the addition of heterogeneous materials in the s...

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

[0035] A polypropylene / polyethylene / polypropylene three-layer co-extruded lithium-ion battery separator, the specific steps of its preparation method are as follows:

[0036] (1) Melting step: Add high-density polyethylene with a molecular weight of 400,000 to 500,000 and a melt index of 0.3 at 190°C and copolymerized polypropylene with a molecular weight of 200,000 to 300,000, a PE block content of 0.5%, and a melt index of 4 at 230°C Two extruders are melted and plasticized; among them, the temperature of the conveying section of the high-density polyethylene extruder is 50-65°C, the temperature of the compression section is 140°C-180°C, the temperature of the melting section is 170°C-200°C, and the temperature of the metering section is 170°C- 190°C, the screw speed is 200rpm; the temperature of the conveying section of the polypropylene extruder is 50-60°C, the temperature of the compression section is 140°C-175°C, the temperature of the melting section is 170°C-210°C, the ...

Embodiment 2

[0043] A polypropylene / polyethylene / polypropylene three-layer co-extruded lithium-ion battery separator, the specific steps of its preparation method are as follows:

[0044] (1) Melting step: Add high-density polyethylene with a molecular weight of 400,000 to 500,000, a melt index of 0.1 at 190°C and a copolymerized polypropylene with a molecular weight of 200,000 to 300,000, a PE block content of 0.1%, and a melt index of 2 at 230°C into two One extruder melts and plasticizes; among them, the temperature of the conveying section of the high-density polyethylene extruder is 60-75°C, the temperature of the compression section is 140°C-195°C, the temperature of the melting section is 175°C-195°C, and the temperature of the metering section is 175°C-215°C °C, the screw speed is 50rpm; the temperature of the conveying section of the polypropylene extruder is 60-75°C, the temperature of the compression section is 140°C-195°C, the temperature of the melting section is 170°C-225°C, t...

Embodiment 3

[0051] A polypropylene / polyethylene / polypropylene three-layer co-extruded lithium-ion battery separator, the specific steps of its preparation method are as follows:

[0052] (1) Melting step: high-density polyethylene with a molecular weight of 500,000 to 600,000 and a melt index of 1 at 190°C and a copolymerized polypropylene with a molecular weight of 300,000 to 400,000, a PE block content of 2%, and a melt index of 8 at 230°C were respectively added to two One extruder melts and plasticizes; among them, the temperature of the conveying section of the high-density polyethylene extruder is 60-70°C, the temperature of the compression section is 160°C-190°C, the temperature of the melting section is 170°C-210°C, and the temperature of the metering section is 170°C-195 °C, the screw speed is 300rpm; the temperature of the conveying section of the polypropylene extruder is 60-70°C, the temperature of the compression section is 160°C-220°C, the temperature of the melting section i...

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
Total thicknessaaaaaaaaaa
Total thicknessaaaaaaaaaa
Login to view more

Abstract

The invention relates to a polypropylene/polyethylene/polypropylene three-layer co-extruded lithium-ion battery separator which adopts an A1/B/A2 three-layer structure. Each of the surface layers A1 and A2 adopts a porous structure formed by co-polypropylene; the middle layer B adopts a porous structure formed by high-density polyethylene. The preparation method comprises steps as follow: high-density polyethylene and co-polypropylene are melted, plastified and then co-extruded synchronously from a three-layer composite casting die head with three cavities to be pulled into films, and a co-extruded cast film with an A1/B/A2 three-layer structure is obtained; annealing treatment, longitudinal cold drawing and thermal stretching are performed, and the polypropylene/polyethylene/polypropylene three-layer co-extruded lithium-ion battery separator is obtained after thermal setting. According to the lithium battery separator, the cell closing temperature of the middle layer is relatively low, the melting temperature of the surface layers is relatively high, the melt completeness and the battery safety of the separator are improved under the condition that a lithium battery is in an extremely high temperature environment, besides, the middle layer has a low melt index, the surface layers have a high melt index, and accordingly, the strength of the middle layer and the plastification uniformity of the surface layers are good.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery diaphragms, and in particular relates to a polypropylene (PP) / polyethylene (PE) / polypropylene (PP) three-layer co-extruded lithium-ion battery diaphragm and a preparation method thereof. Background technique [0002] The diaphragm is the key material that determines the internal interface structure, internal resistance, capacity, cycle performance, and especially the safety performance of lithium batteries. Under overcharge / overdischarge or other extreme conditions, the internal temperature of lithium batteries will rise rapidly. When the internal temperature of the battery is close to the melting point of the pore-forming material of the separator, the pore-forming material will soften and close the pores, thereby blocking ion transmission and forming an open circuit, which plays a role of safety protection. However, due to the same closure temperature and melting temperature of the ...

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): H01M2/14H01M2/16H01M10/0525H01M50/403H01M50/417
CPCH01M10/0525H01M50/403H01M50/411Y02E60/10
Inventor 唐浩林王红兵马兴玉
Owner HUIQIANG WUHAN NEW ENERGY MATERIAL TECH
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