Battery Separator Adhesive Layer for High Adhesion and Low Resistance
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Solution Overview
Problem
Existing electrochemical device separators face challenges in enhancing adhesion between electrodes while minimizing increases in air permeability and resistance, which affect battery performance and safety.
Innovation Solution
Incorporating a water-soluble polymer binder in an adhesive layer on a porous polymer substrate with a coating layer containing inorganic particles, along with a water-insoluble polymer binder, to improve adhesion and maintain porosity and reduce resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating layer with inorganic particles is added to enhance thermal stability, then thermal shrinkage resistance is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies composite materials by combining organic polymer substrate with inorganic particles (such as metal oxides or ceramics) to create a coating layer that exhibits both the flexibility and porosity of polymers and the thermal stability of inorganic materials. This composite structure resolves the contradiction by achieving thermal shrinkage resistance without sacrificing the inherent advantages of polymer separators.
Solution Approach 2:
The patent utilizes porous materials by maintaining a porous structure in the coating layer with controlled pore size and distribution. This allows the coating to provide thermal stability while preserving ion transport pathways, thus achieving thermal shrinkage resistance without blocking electrolyte penetration or increasing manufacturing complexity excessively.
2Strength
If adhesive layer thickness is increased to improve adhesion between separator and electrodes, then adhesion strength is improved, but air permeability and resistance increase
Solution Approach 1:
The patent applies parameter changes by optimizing the thickness of the adhesive layer to a specific range that balances adhesion strength and permeability. Additionally, the porosity, pore size, and material composition of the adhesive layer are adjusted to achieve maximum adhesion while maintaining adequate ion transport, thus resolving the contradiction between strength and reliability.
Solution Approach 2:
The patent uses local quality by creating regions with different properties within the adhesive layer. The adhesive layer contains both binder materials for strong bonding and porous regions for ion transport, allowing different zones to fulfill different functions - strong adhesion at the interface and high permeability in the bulk, thus resolving the contradiction between adhesion strength and air permeability.
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 enhances adhesion between electrodes, suppresses increases in air permeability and resistance, and improves battery performance by maintaining porosity and mechanical properties.
Implementation Method 1
an adhesive layer containing a small amount of water-soluble polymer binder on a coating layer to enhance the adhesion between the separator and the electrodes
Implementation Method 2
the separator includes a porous polymer substrate disposed between the positive electrode and the negative electrode, and takes on the role of separating the positive electrode and the negative electrode, preventing an electrical short circuit between the two electrodes, and allowing the passage of electrolyte and ions
Data Source
AI summary
The present disclosure relates to an electrochemical device separator, which includes an adhesive layer containing a small amount of water-soluble polymer binder on a coating layer to enhance the adhesion between the separator and the electrodes, and further, suppress the increase in air permeability and resistance of the separator, an electrochemical device including the same, and a manufacturing method thereof.