Porous Separator Coating With Filmed Binder for Durable Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional aqueous particle type polymer binders used in porous coating layers for electrochemical devices suffer from low durability, leading to easy separation from the porous base during manufacturing, compromising the integrity of the electrode assembly.
Innovation Solution
A separator for electrochemical devices featuring a porous coating layer with a specific composition and structure, including a filmed area formed by deforming polymer binder particles, which enhances adhesion strength and durability without degrading air permeability and electrical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an aqueous particle type polymer binder is used to form a porous coating layer on a porous base, then the coating layer provides excellent heat resistance and adhesion strength, but the coating layer has low durability and is easily separated from the porous base during manufacturing
Solution Approach 1:
The patent changes the physical state of the polymer binder from particle form to film form by controlling the drying process. The binder is applied as particles in a slurry, then dried to form a continuous film that provides both strong adhesion and high durability. This parameter change (from discrete particles to continuous film) resolves the contradiction between adhesion strength and durability.
2Strength
If the polymer binder particles are deformed to form a filmed area, then the adhesion strength between the porous coating layer and the porous polymer base is improved, but the air permeability and electrical resistance may be degraded
Solution Approach 1:
The patent applies local quality by creating a filmed area only in specific regions where adhesion is needed, while maintaining particle area in other regions to preserve porosity and air permeability. The filmed area is formed by selective deformation of binder particles at the interface with the porous base, providing strong local adhesion without compromising the overall air permeability of the coating layer.
Solution Approach 2:
The patent maintains the porous structure of the coating layer by not completely densifying the binder material. The filmed area provides adhesion while the overall coating layer retains its porous nature through the particle area regions and controlled drying, ensuring air permeability and electrical resistance are not degraded.
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 separator achieves improved adhesion strength between the porous coating layer and the porous polymer base, ensuring durability and maintaining optimal performance characteristics of the electrochemical device.
Implementation Method 1
a filmed area comprising deformed polymer binder particles and formed on at least one surface of the porous polymer base
Implementation Method 2
forming a filmed area by deforming 3 wt % to 50 wt % of the polymer binder particles with respect to a total weight of the polymer binder particles
Data Source
AI summary
Disclosed is a separator for an electrochemical device. The separator includes a porous polymer base, and a porous coating layer including a particle area formed of polymer binder particles and inorganic particles and a filmed area including deformed polymer binder particles and formed on at least one surface of the porous polymer base. The filmed area is in the range of 3 to 50 wt % with respect to the total weight of the polymer binder particles.