Laminated Battery Separator Coating for Thin-Support Stability
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Solution Overview
Problem
Conventional separators using polyethylene face issues with heat resistance and air permeability, leading to safety concerns and reduced battery performance, while thinner porous supports suffer from mechanical instability and reduced productivity during coating processes.
Innovation Solution
A method involving laminating two porous supports to form a laminate, applying a functional layer on both sides, and dividing it into separators improves productivity and quality by enhancing mechanical stability and coating workability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heat-resistant layer containing ceramic particles is coated on the surface of the porous support, then heat resistance is improved, but air permeability is reduced
Solution Approach 1:
The patent uses a porous coating layer containing ceramic particles and binder that maintains porosity to allow ion transfer. The coating layer is designed with controlled pore structure to prevent pore closure while providing heat resistance, ensuring both thermal stability and ion permeability are achieved simultaneously.
Solution Approach 2:
The patent creates a composite coating layer combining ceramic particles (for heat resistance) with binder material (for adhesion and structural integrity). This composite structure allows the coating to provide thermal protection while maintaining the necessary porosity for ion transport through the porous support.
2Quantity of substance
If the thickness of the porous support is reduced to about 15 μm or less, then battery capacity is increased, but mechanical properties and traveling stability are reduced
Solution Approach 1:
The patent employs a composite structure combining a thin porous support (15 μm or less) with a functional coating layer containing ceramic particles and binder. This composite design allows the thin support to provide high battery capacity while the coating layer reinforces mechanical properties and provides thermal stability.
Solution Approach 2:
The patent applies functional coating layers selectively on the porous support to provide localized mechanical reinforcement and heat resistance where needed, while maintaining the overall thin profile for high capacity. The coating is applied in specific regions to enhance properties without adding unnecessary thickness.
3Quantity of substance
If the thickness of the porous support is reduced to about 15 μm or less, then battery capacity is increased, but productivity is reduced
Solution Approach 1:
The patent prepares the porous support with pre-formed micropores and appropriate surface characteristics before applying the functional coating. This preliminary preparation ensures that the coating process proceeds smoothly without requiring excessive processing time, maintaining high productivity even with thin supports.
Solution Approach 2:
The patent optimizes coating parameters such as coating thickness, ceramic particle size distribution, and binder composition to achieve the desired functional properties with minimal coating thickness. This allows rapid coating processes that maintain high productivity while providing sufficient heat resistance and mechanical reinforcement.
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 method enables high-quality separators with improved heat resistance, air permeability, and mechanical stability, maintaining productivity levels even with thin supports, thus addressing safety and performance issues.
Implementation Method 1
a microporous separator using a microporous membrane formed with micropores that separates a positive electrode and a negative electrode to prevent an internal short circuit and allow lithium ions to move smoothly in a charging and discharging process
Implementation Method 2
particularly a polyolefin such as polyethylene which is advantageous for pore formation by thermally induced phase separation
Data Source
AI summary
One aspect of the present invention provides a method of manufacturing a separator including: (a) obtaining a laminate by laminating a first porous support and a second porous support; (b) forming a functional layer by applying a composition including a binder and a solvent on both sides of the laminate and drying the composition; and (c) dividing the laminate into two separators along an interface formed by the lamination, and a separator manufactured using the method.