Nonwoven Battery Separator With Baroplastic Pore Shutdown
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Solution Overview
Problem
Conventional non-woven fabric separators for secondary batteries face issues with self-discharge, uneven electrolyte impregnation, and inadequate shutdown function at high temperatures, leading to stability and safety concerns.
Innovation Solution
Impregnating porous non-woven fabric materials with a baroplastic polymer powder and pressing them to fill pores, followed by coating with a binder solution and laminating electrodes, to create a separator that inhibits self-discharge and provides a shutdown function at temperatures up to 200°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If non-woven fabric separators with large pores are used to improve heat resistance, then heat resistance is improved, but self-discharge occurs and shutdown function is insufficient
Solution Approach 1:
The separator performs preliminary action by shutting down (closing pores) at moderate temperatures (130-200°C) before critical high temperatures are reached, preventing self-discharge and safety issues in advance
Solution Approach 2:
The separator changes its physical parameter (pore closure) in response to temperature changes, transitioning from an open porous state at low temperatures to a closed state at elevated temperatures, thereby adapting its properties to prevent self-discharge
2Temperature
If non-woven fabric separators with high porosity are used to improve heat resistance, then heat resistance is improved, but electrolyte impregnation becomes uneven or insufficient
Solution Approach 1:
The separator achieves local quality by having different regions or aspects serve different functions: the base non-woven fabric provides heat resistance while the baroplastic polymer coating provides controlled pore closure and improved electrolyte distribution in critical areas
3Manufacturing precision
If conventional polyolefin polymer separators are used to achieve good electrolyte impregnation, then electrolyte impregnation is good, but shutdown function and heat resistance are insufficient
Solution Approach 1:
The separator uses composite materials by combining conventional polyolefin polymer (providing good electrolyte impregnation) with baroplastic polymer (providing shutdown function and heat resistance), achieving both requirements simultaneously
Solution Approach 2:
The separator merges two different polymer materials with complementary properties: the polyolefin polymer ensures good electrolyte impregnation while the baroplastic polymer provides temperature-responsive shutdown function, combining their advantages in a single separator structure
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents self-discharge, enhances electrolyte impregnation, and ensures a shutdown function at high temperatures, thereby improving the stability and safety of secondary batteries.
Implementation Method 1
pressing the porous non-woven fabric material upon assembly of a secondary battery such that the pores of the porous non-woven fabric material may be filled with the baroplastic polymer powder
Implementation Method 2
a shutdown function may be provided at a high temperature of about 200° C. or less and an internal short-circuit may be prevented
Data Source
AI summary
Disclosed are a separator for secondary batteries with enhanced stability and a method of manufacturing the separator. The separator can prevent self-discharge which may occur when a porous non-woven fabric material is used for a separator; can perform a shutdown function at a high temperature of 200° C. or less; and can avoid even under harsh conditions of high temperatures, deterioration in stability caused by internal short-circuit of positive and negative electrodes. In particular, the separator for secondary batteries of the present invention includes a porous non-woven fabric material impregnated with a baroplastic polymer powder and pores of the porous non-woven fabric material are filled with the baroplastic polymer powder by pressing an assembly of the secondary battery.