Separator Coating Layer Adhesion and Thermal Stability
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Solution Overview
Problem
Large-sized electrochemical battery separators face challenges with adherence and thermal stability, leading to shape instability and potential detachment during manufacturing and storage, especially when applied to batteries with varying sizes and shapes.
Innovation Solution
A separator with a base film coated on one or both surfaces with an organic binder, specifically an acryl-based copolymer, and inorganic particles, which maintains a thickness change rate below 3% and provides improved adherence and thermal stability by minimizing thermal shrinkage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a large-sized separator is used to increase battery area, then battery capacity increases, but the separator becomes easily detached and shape stability deteriorates
Solution Approach 1:
The patent applies composite materials by forming an organic/inorganic mixed coating layer on the separator surface. The coating layer comprises inorganic particles (such as Al2O3, SiO2, TiO2, or ZrO2) dispersed in an organic binder polymer matrix. This composite structure combines the mechanical properties of the organic binder with the thermal stability and surface properties of inorganic particles, creating a coating that significantly improves adherence to electrodes while maintaining the large area required for high capacity batteries.
2Area of stationary object
If a large-sized separator is used to increase battery area, then battery capacity increases, but shape stability during manufacturing and storage deteriorates
Solution Approach 1:
The organic/inorganic mixed coating layer acts as a stabilizing composite structure on the separator surface. The inorganic particles provide rigid structural support that resists deformation, while the organic binder holds the particles together and adheres them to the separator substrate. This composite architecture prevents thermal shrinkage and maintains shape stability during manufacturing processes and long-term storage, even for large-sized separators.
3Reliability
If an organic/inorganic mixed coating layer is formed to improve adherence, then adherence increases, but thermal stability is insufficient
Solution Approach 1:
The patent resolves this contradiction by creating a synergistic composite coating where inorganic particles (Al2O3, SiO2, TiO2, ZrO2) provide high thermal stability and heat resistance, while the organic binder polymer ensures good adherence to electrodes. The inorganic particles have high melting points and maintain structural integrity at elevated temperatures, preventing thermal shrinkage, while the organic component provides adhesive properties. This composite approach achieves both improved adherence and sufficient thermal stability simultaneously.
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 ensures long-term storage stability and prevents detachment during manufacturing, enhancing the shape stability and heat resistance of the separator, thereby improving the performance of large-sized electrochemical batteries.
Implementation Method 1
the separator having applicable properties such as adherence, a thermal shrinkage ratio, and the like to the large-sized electrochemical battery
Data Source
AI summary
The present invention relates to a separator comprising a coating layer and a battery using the same, the separator having improved adhesive force to an electrode, thereby minimizing the rate of thickness change. More specifically, the present invention relates to a separator having a coating layer on one or both surfaces of a base film, the coating layer comprising an acrylic-based copolymer having a glass transition temperature of less than or equal to 80° C. and an inorganic particle, so as to have improved adhesive force and heat resistance, thereby being applicable in electrochemical batteries of various sizes and having excellent thermal stability and dimensional stability.