Fuel Cell Current Collector Corrugation Without Draw-Forming Thinning
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Solution Overview
Problem
Current methods for manufacturing corrugated current collectors in fuel cells, such as draw forming, result in material thinning, stress impartation, and non-uniformity, leading to reduced lifespan and electrical conductivity.
Innovation Solution
The method involves bend-forming a base plate to create open corrugations and using additive manufacturing techniques like selective laser sintering or laser metal deposition to form feet from different materials, which are then metallurgically joined to the flanges, allowing for improved flatness and customizable gas flow control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If draw forming is used to manufacture corrugated current collectors, then the corrugated structure is formed, but material thinning and stress impartation occur leading to reduced lifespan and electrical conductivity
Solution Approach 1:
The current collector is divided into two distinct parts: a base plate made from one material and feet made from a different material. The base plate provides structural support while the feet provide enhanced electrical conductivity and corrosion resistance at the contact points with the membrane electrode assembly. This segmentation allows each part to be optimized for its specific function without compromising the other.
Solution Approach 2:
The current collector uses composite construction with dissimilar materials - typically a stainless steel base plate combined with nickel or nickel-alloy feet. This composite approach leverages the high strength and formability of stainless steel for the base structure while utilizing the superior electrical conductivity and corrosion resistance of nickel at the critical contact interfaces, thereby resolving the contradiction between structural integrity and electrical performance.
2Reliability
If additive manufacturing is used to form feet, then different materials can be used for feet and base plate improving contact pressure uniformity, but manufacturing complexity increases
Solution Approach 1:
The manufacturing process merges two different fabrication techniques - traditional metal forming for the base plate and additive manufacturing for the feet. The base plate is formed using conventional stamping or rolling processes, while the feet are selectively deposited using additive manufacturing technologies such as selective laser melting or electron beam melting. This combination allows complex geometries and material property gradients to be achieved while maintaining manufacturing efficiency.
Solution Approach 2:
Additive manufacturing enables local quality variation by allowing the feet to have different material composition, density, and microstructure optimized for their specific function at the contact interface. The feet can be selectively deposited with controlled porosity, alloy composition, and geometric features to achieve uniform contact pressure distribution, while the base plate maintains its simple homogeneous structure for structural support.
3Strength
If feet are metallurgically joined to flanges, then bond strength is improved, but manufacturing precision requirements increase
Solution Approach 1:
The joining process utilizes parameter changes in the form of thermal energy input to achieve metallurgical bonding. Additive manufacturing processes such as selective laser melting or electron beam melting employ controlled thermal fields to locally melt and fuse the feet to the base plate flanges. By precisely controlling temperature, heating rate, and cooling rate parameters, strong metallurgical bonds are achieved while minimizing thermal distortion and maintaining manufacturing precision.
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
This approach enhances the durability and electrical conductivity of current collectors by minimizing material thinning and stress, while enabling the use of different materials for the feet, leading to improved contact pressure uniformity and gas flow management within fuel cell stacks.
Implementation Method 1
The feet are formed using selective laser sintering, selective laser melting, laser metal deposition
Implementation Method 2
The feet are formed using selective laser sintering, selective laser melting, laser metal deposition
Implementation Method 3
The feet are formed using selective laser sintering, selective laser melting, laser metal deposition
Data Source
AI summary
A method of manufacturing a current collector for an electrochemical cell assembly includes providing a base plate including a surface, bend-forming the base plate to create a plurality of open corrugations protruding from the surface, each open corrugation including a first flange and a second flange, and forming a foot between the first flange and the second flange of each open corrugation to close each open corrugation and form a corrugation.