Fuel Cell Gas Diffusion Layer Coating for Bending Stiffness and Flexibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas diffusion layers for fuel cells, particularly those made from carbon fiber papers, exhibit high bending stiffness but poor flexibility, leading to material embrittlement and rupture under bending loads, while nonwoven fabrics offer flexibility but lack sufficient stiffness.
Innovation Solution
A gas diffusion layer composed of carbon fiber nonwoven or woven fabrics coated with a combination of fluorine-containing polymers and high-performance thermoplastics, such as polyaryletherketones and polyphenylene sulfides, to enhance both bending stiffness and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If carbon fiber papers are used for gas diffusion layer, then bending stiffness is improved, but flexibility deteriorates and material embrittlement occurs
Solution Approach 1:
The patent applies composite materials by combining carbon fiber nonwoven or woven fabrics with fluorine-containing polymers and high-performance thermoplastics. This composite structure enables the gas diffusion layer to simultaneously achieve high bending stiffness from the carbon fiber framework and enhanced flexibility from the polymer matrix, resolving the contradiction between stiffness and flexibility that plagues conventional carbon fiber paper-based GDLs.
Solution Approach 2:
The patent changes the material parameters by transitioning from traditional carbon fiber papers to carbon fiber nonwoven/woven fabrics with specific polymer coatings. This parameter change in the substrate material structure fundamentally alters the mechanical properties, enabling both high bending stiffness and improved flexibility to coexist without material embrittlement.
2Ease of operation
If carbon fiber nonwoven fabrics are used for gas diffusion layer, then flexibility is improved, but bending stiffness deteriorates
Solution Approach 1:
The patent uses composite materials where carbon fiber nonwoven or woven fabrics provide the flexible substrate structure, while the incorporated fluorine-containing polymers and high-performance thermoplastics contribute to the mechanical reinforcement. This composite approach allows the GDL to achieve both the flexibility of nonwoven fabrics and the bending stiffness required for mechanical stability.
3Strength
If fluorine-containing polymers and high-performance thermoplastics are combined in coating, then bending stiffness is improved, but material complexity increases
Solution Approach 1:
The patent applies composite materials by combining carbon fiber nonwoven or woven fabrics with fluorine-containing polymers and high-performance thermoplastics. This composite structure enables the gas diffusion layer to simultaneously achieve high bending stiffness from the carbon fiber framework and enhanced flexibility from the polymer matrix, resolving the contradiction between stiffness and flexibility that plagues conventional carbon fiber paper-based GDLs.
Data Source
AI summary
A gas diffusion layer for a fuel cell, including a flat electrically conductive material and/or a sintered product of the flat electrically conductive material. The flat electrically conductive material includes at least one fiber material selected from the group consisting of carbon fiber nonwoven fabrics, carbon fiber woven fabrics, and a combination thereof. The at least one fiber material includes at least one fluorine-containing polymer and at least one polymer different from the at least one fluorine-containing polymer selected from the group consisting of polyaryletherketones, polyphenylene sulfides, polysulfones, polyethersulfones, partially aromatic (co)polyamides, polyimides, polyamide-imides, polyether-imides and combinations thereof. The at least one fluorine-containing polymer and the at least one polymer different from the at least one fluorine-containing polymer are applied to the at least one fiber material and/or incorporated therein.