Fuel Cell Gasket Bonding Structure for Durable MEA Sealing
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Solution Overview
Problem
Solid rubber gaskets, such as EPDM and fluorine rubber, face challenges in achieving fluidity and rapid hardening at low temperatures, making it difficult to integrate them with electrode members in fuel cell assemblies without degrading the electrolyte membrane or gas diffusion layer, and they lack durability and sealability when used in fuel cell stacks.
Innovation Solution
A fuel cell assembly with a solid rubber gasket and an electrode member integrated using a thermoplastic polymer bonding member, where the bonding member is impregnated into the gas diffusion layer or bonded to the membrane electrode assembly, ensuring the electrolyte membrane is protected and the gasket is securely attached, enhancing sealability and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicone rubber is used as gasket material and injection molded, then sealability is enhanced through impregnation with gas diffusion layer, but siloxane bonds hydrolyze in fuel cell operation environment causing degradation in sealability and contamination of MEA
Solution Approach 1:
The patent changes the material parameter from silicone rubber to fluorine rubber, which has different chemical properties that resist hydrolysis. Fluorine rubber maintains its sealing properties without degrading in the fuel cell's operational environment, thus improving both reliability and durability simultaneously.
Solution Approach 2:
The patent uses fluorine rubber as a composite material that combines the desired sealing properties with chemical stability. The fluorine-containing polymer structure provides both excellent sealability and resistance to hydrolysis, eliminating the trade-off between initial sealing performance and long-term durability.
2Duration of action of stationary object
If solid rubber such as EPDM or fluorine rubber is used for gasket, then durability and high-temperature characteristics are improved, but fluidity is insufficient making it difficult to integrate with electrode member through injection molding at low temperature
Solution Approach 1:
The patent introduces a bonding member as an intermediary substance that bridges the solid rubber gasket and the electrode member. This bonding member enables integration through bonding rather than injection molding, allowing the use of durable solid rubber materials while achieving secure attachment to the electrode assembly.
Solution Approach 2:
The patent segments the integration process into two distinct functions: the gasket provides sealing and durability, while the bonding member provides attachment. This separation allows each component to be optimized independently - the gasket for durability and the bonding member for ease of integration.
3Duration of action of stationary object
If EPDM or fluorine rubber gasket is hardened near electrolyte membrane, then durability is improved, but electrolyte membrane may be degraded due to heat at hardening time
Solution Approach 1:
The patent separates the hardening process from the electrolyte membrane by positioning the gasket and bonding member away from the membrane area. The bonding member is applied to the frame and gasket structures that do not directly contact the electrolyte membrane, allowing hardening without thermal damage to the membrane.
Solution Approach 2:
The bonding member acts as an intermediary that allows the gasket to be securely attached without requiring the gasket material itself to be hardened near the electrolyte membrane. The bonding process occurs in regions that do not expose the membrane to harmful temperatures.
4Duration of action of stationary object
If gasket material is selected for excellent durability and high-temperature characteristics, then reliability is improved, but gas permeability may increase reducing sealing performance
Solution Approach 1:
The patent employs fluorine rubber as a composite material that simultaneously provides durability, high-temperature resistance, and low gas permeability. The fluorine-containing polymer structure creates a dense matrix that resists gas penetration while maintaining structural stability and chemical inertness in the fuel cell environment.
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 integration of a solid rubber gasket with a thermoplastic polymer bonding member improves the sealability, durability, and handleability of fuel cell assemblies by preventing degradation and contamination, while allowing for efficient manufacturing and easy repairability.
Implementation Method 1
the bonding member is impregnated into the gas diffusion layer or bonded to the membrane electrode assembly
Implementation Method 2
a bonding member that has a thermoplastic polymer, is disposed in a frame shape on an outward side of the electrode member in the surface direction, is bonded to the electrode member and the gasket, and integrates the electrode member and the gasket
Data Source
AI summary
A fuel cell assembly includes an electrode member that has a membrane electrode assembly having an electrolyte membrane and an electrode catalyst layer, and gas diffusion layers; a solid rubber gasket that is disposed in a frame shape on an outward side of the electrode member in a surface direction; and a bonding member that is disposed in a frame shape on the outward side of the electrode member in the surface direction, is bonded to the electrode member and the gasket, and integrates these. A form of bonding the bonding member to the electrode member is at least one of impregnation with the gas diffusion layers and bonding to the membrane electrode assembly. A thickness of the bonding member is equal to or larger than a thickness of the gas diffusion layer, and at least a portion on a surface of the bonding member is coated with the gasket.