Inorganic-Coated Battery Separator With Silane Binder for Peel Strength
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Solution Overview
Problem
Existing separators for electrochemical devices face challenges in maintaining dimensional stability at high temperatures, leading to potential internal short circuits and safety issues due to insufficient bonding characteristics and thermal stability of silane compounds used as binders.
Innovation Solution
A separator with an inorganic particle layer on a porous substrate, utilizing a hydrolytic condensate binder of a polar silane compound and an aqueous polymer binder, which enhances peel strength, thermal stability, and adhesion to prevent particle release and improve safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a silane compound is used as the binder of the inorganic particle layer, then thermal stability is improved to some extent, but bonding characteristics are still lacking and inorganic particles may be released during cell assembly
Solution Approach 1:
The patent uses a composite binder system combining silane compound with polyvinylidene fluoride (PVDF) and carboxymethyl cellulose (CMC). This composite approach leverages the thermal stability of silane while PVDF and CMC provide enhanced bonding characteristics, preventing inorganic particle release during cell assembly. The synergistic combination resolves the contradiction between thermal stability and bonding strength.
Solution Approach 2:
The patent optimizes the composition ratios of silane compound, PVDF, and CMC in the binder, along with controlling the particle size distribution of inorganic particles (0.1-10 μm). These parameter changes enhance both thermal stability and bonding characteristics simultaneously, preventing particle release while maintaining heat resistance.
2Temperature
If an inorganic particle layer is stacked on the porous substrate to improve dimensional stability at high temperature, then thermal stability is improved, but peel strength and adhesion are insufficient
Solution Approach 1:
The binder composite consisting of silane compound, PVDF, and CMC provides both thermal stability for dimensional stability at high temperature and sufficient peel strength through the adhesive properties of PVDF and CMC. This composite material approach resolves the contradiction between thermal stability and adhesion.
Solution Approach 2:
The patent creates an inorganic particle layer with specific local properties: inorganic particles (0.1-10 μm) provide thermal stability while the binder composite provides adhesion. The layered structure with porous substrate and inorganic particle layer creates local quality differentiation that achieves both dimensional stability and peel strength.
3Stability of the object's composition
If inorganic particles are used in the inorganic particle layer to maintain structural integrity, then thermal stability is improved, but particles may be released during cell assembly causing defects
Solution Approach 1:
The composite binder system of silane compound, PVDF, and CMC provides sufficient bonding strength to hold inorganic particles firmly in place during cell assembly, preventing particle release while maintaining structural integrity. The combination resolves the contradiction between structural integrity and particle release prevention.
Solution Approach 2:
The patent controls the particle size of inorganic particles within 0.1-10 μm and optimizes the binder composition ratios, which enhances both structural integrity and particle retention. These parameter changes ensure particles remain firmly bound during assembly while maintaining the layer's structural stability.
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 significantly improves thermal stability, peel strength, and adhesion, reducing heat shrinkage rates and preventing particle release, thereby enhancing battery safety and performance at high temperatures.
Implementation Method 1
a hydrolytic condensate binder of a polar silane compound
Implementation Method 2
bonding characteristics and thermal stability are still lacking
Implementation Method 3
dimensional stability at a high temperature
Implementation Method 4
an organic-inorganic composite porous separator in a form in which an inorganic particle layer is stacked on the surface of a porous substrate has been developed
Implementation Method 5
an inorganic particle layer which is provided on at least one surface of the porous substrate
Data Source
AI summary
Provided are a separator, a method of manufacturing the separator, and an electrochemical device including the separator. According to an exemplary embodiment of the present disclosure, a separator including a porous substrate and an inorganic particle layer provided on at least one surface of the porous substrate, the inorganic particle layer including inorganic particles, a hydrolytic condensate binder of a polar silane compound, and an aqueous polymer binder, wherein an amount of change in peel strength, △P, represented by the following Equation (1) is 1.1 or more may be provided: ΔP=P1/P2 wherein P1 is peel strength of the separator, P2 is peel strength of a separator including a porous substrate and an inorganic particle layer which is provided on at least one surface of the porous substrate and includes boehmite particles and a hydrolytic condensate of (3-aminopropyl)triethoxysilane, and the peel strength is measured by adhering a double-sided tape having a width of 15 mm and a length of 60 mm from one end in a length direction on a copper plate having a thickness of 200 µm, a width of 15 mm, and a length of 100 mm, adhering the separator thereon by stacking and pressing so that the tape faces the inorganic particle layer of the separator, and using UTM equipment to perform a 180° peel test under conditions of a speed of 300 mm/min and a displacement of 100 mm.