Solid Oxide Fuel Cell Separator With Local Quality Variation
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Solution Overview
Problem
In solid oxide fuel cell stacks, the deformation of separators due to stacking loads creates gaps between the separator and the fuel cell electrodes, increasing contact resistance and reducing power generation efficiency.
Innovation Solution
The separator is designed with a higher section modulus in its abutting portions compared to its connecting portions, preventing deformation and maintaining close contact between the separator and the fuel cell electrodes, thereby reducing contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the separator is pressed in the lamination direction during stacking, then the connecting portion deforms to decrease separator thickness, but the abutting portion bends and generates gaps between the separator and fuel cell electrode
Solution Approach 1:
The separator is designed with non-uniform thickness distribution, where the abutting portion has a greater section modulus (is thicker) than the connecting portion. This local quality variation allows the abutting portion to resist bending and maintain contact with the electrode, while the thinner connecting portion can deform to reduce overall separator thickness and assembly height.
2Reliability
If the abutting portion of the separator has a larger section modulus than the connecting portion, then close contact between separator and fuel cell is maintained, but the separator structure becomes more complex
Solution Approach 1:
The separator employs local quality variation by making the abutting portion thicker than the connecting portion. This creates a functionally optimized structure where each region has different properties suited to its role: the thicker abutting portion maintains structural integrity and contact pressure, while the thinner connecting portion reduces overall height and allows necessary deformation.
Data Source
AI summary
A fuel cell stack includes a plurality of fuel cells stacked via separators, each one of which cells has a solid electrolyte plate interposed between an anode electrode and a cathode electrode. The separator is constituted of an uneven member that includes a first abutting portion, a second abutting portion, and a connecting portion, the first abutting portion abuts on one fuel cell of the two adjacent fuel cells, the second abutting portion abuts on the other fuel cell, and the connecting portion connects the first abutting portion to the second abutting portion. At least one abutting portion of the first abutting portion or the second abutting portion has a section modulus greater than a section modulus of the connecting portion.