Composite Fuel Cell Stack End Plates for Lightweight Stiffness
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Solution Overview
Problem
Fuel cell stacks used in vehicles are heavy due to the need for stiff end plates to withstand external loads, which decreases vehicle range and increases weight.
Innovation Solution
End plates made of fibre reinforced matrix material, such as carbon or glass fibres, with connection straps and pins, providing stiffness and sealing without additional weight, and eliminating the need for separate insulating plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If end plates are made stiff to withstand external loads, then mechanical strength and stability are improved, but weight increases significantly
Solution Approach 1:
The end plate is constructed as a composite structure consisting of a rigid core element (providing mechanical strength and stiffness) surrounded by a flexible membrane material (reducing weight). This composite approach allows the end plate to withstand external loads while significantly reducing overall weight compared to traditional solid metal plates.
Solution Approach 2:
The end plate incorporates a flexible membrane material as the outer layer that surrounds the rigid core. This membrane provides the necessary structural integrity while being much lighter than solid metal plates, directly addressing the weight reduction goal while maintaining load-bearing capability.
2Stability of the object's composition
If end plates are made heavier to increase stiffness, then ability to cope with external loads is improved, but vehicle range decreases
Solution Approach 1:
The composite construction with rigid core and flexible membrane provides high stiffness-to-weight ratio, reducing overall end plate weight while maintaining structural stability. This weight reduction directly improves vehicle energy efficiency and extends operating range.
Solution Approach 2:
The flexible membrane material creates a lightweight yet stiff structure that resists external loads effectively. By using this thin-film approach instead of thick solid plates, the end plate achieves necessary stiffness with minimal weight, thereby improving vehicle range.
3Strength
If traditional metal end plates are used, then mechanical strength is sufficient, but weight reduction potential is lost
Solution Approach 1:
Replacing traditional solid metal end plates with a composite structure (rigid core + flexible membrane) maintains structural strength while achieving significant weight reduction. The rigid core provides necessary strength, while the membrane adds minimal weight.
Solution Approach 2:
The flexible membrane material replaces heavy metal plating while maintaining structural integrity. This thin-film construction provides sufficient strength for containing fuel cells and withstanding external loads at a fraction of the weight of traditional metal plates.
4Reliability
If separate insulating plates are added for electrical insulation, then electrical isolation is improved, but device complexity and weight increase
Solution Approach 1:
The flexible membrane material serves multiple functions simultaneously: it provides electrical insulation between the fuel cell and end plate, contributes to the structural strength of the end plate, and reduces overall weight. This multi-functionality eliminates the need for separate insulating plates.
Solution Approach 2:
The electrical insulation function is merged into the flexible membrane material itself rather than being provided by a separate component. This integration simplifies the overall structure, reduces the number of parts, and maintains reliable electrical insulation.
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
Significantly reduces end plate weight by up to 70%, increasing power density and vehicle range while maintaining mechanical stability and electrical insulation.
Implementation Method 1
the connection straps consist of fibre reinforced matrix material and are wound around connection lugs connected to connection pins of the end plates
Implementation Method 2
The connection straps in particular are used to provide a compression force along the stack direction to compress the fuel cell stacks and thereby seal them against each other
Data Source
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AI summary
The invention is related to a fuel cell stack (100) for a fuel cell system (200) comprising multiple fuel cells (110) stacked upon each other along a stack direction (SD), wherein the fuel cells (110) are enclosed by end plates (10), wherein the end plates (10) are mechanically connected with each other by connection straps (120) extending along the stack direction (SD) on different sides of the fuel cells (110), wherein the connection straps (120) consist of fibre reinforced matrix material and are wound around connection lugs (122) connected to connection pins (60) of the end plates (10).