Polymerizable Battery Separator Coating for Heat-Stable Gel Adhesion
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Solution Overview
Problem
Lithium secondary batteries face challenges with separator adhesion to gel polymer electrolytes, leading to reduced performance and safety due to low adhesion and potential internal short circuits, especially under heat and mechanical stress.
Innovation Solution
A separator with a coating layer containing an organic binder with ethylenically unsaturated groups, which undergoes radical polymerization with oligomers containing (meth)acrylate groups to form a polymer network, enhancing adhesion to the gel polymer electrolyte and improving mechanical strength and lithium ion transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polyethylene (PE) is used as separator material, then manufacturing is simplified, but thermal stability deteriorates at high temperature
Solution Approach 1:
The invention applies a composite coating layer on the PE separator substrate. The inorganic particles (such as metal oxides) in the coating provide high thermal stability and heat resistance, while the PE substrate maintains manufacturing simplicity. The coating layer protects the PE from direct thermal degradation at high temperatures
Solution Approach 2:
The invention applies different properties to different parts of the separator system: the PE substrate provides ease of manufacture and basic separation function, while the coated surface layer provides enhanced thermal stability and adhesion. This local differentiation allows each component to optimize its specific function
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 improved adhesion and mechanical strength of the separator enhance the battery's output properties, lifespan, and safety by reducing internal resistance and preventing short circuits and thermal runaway.
Implementation Method 1
a polymer network in a three-dimensional structure is formed by a polymerization reaction between the organic binder included in the separator and containing an ethylenically unsaturated group and the oligomer containing a (meth) acrylate group
Data Source
AI summary
The present invention relates to a separator for a secondary battery, the separator including a substrate and a coating layer formed on the surface of the substrate, wherein the coating layer includes an organic binder and inorganic particles, and the organic binder contains an ethylenically unsaturated group, and to a lithium secondary battery including the same.