Chromium Getter Coated Substrate for Solid Oxide Fuel Cell Cathode Protection
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Solution Overview
Problem
Volatile chromium species from stainless steel components in solid oxide fuel cell stacks degrade cathode performance due to deposition at electrochemically active regions, especially exacerbated by humidity.
Innovation Solution
A chromium-getter material, such as calcium carbonate, is bonded to an inert alumina substrate to form a coated substrate that captures chromium species before they reach the cathode, reducing contamination and performance degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If stainless steel components are used in the fuel cell stack, then structural strength and durability are improved, but chromium vapor is generated that degrades cathode performance
Solution Approach 1:
A chromium-getter material is introduced as an intermediary component between the stainless steel interconnect and the cathode. This getter material captures chromium vapor through chemical reaction, preventing it from reaching and contaminating the cathode, thus resolving the contradiction between using stainless steel for structural strength and preventing chromium contamination.
Solution Approach 2:
The harmful chromium vapor generated by stainless steel components is converted into a beneficial effect by using a chromium-getter material that reacts with and captures the chromium. The previously harmful chromium species are transformed into stable chromium-containing compounds that remain on the getter material, thereby protecting the cathode while allowing the use of stainless steel interconnects.
2Reliability
If chromium-getter material is added to capture chromium vapor, then cathode performance degradation is reduced, but device complexity increases
Solution Approach 1:
The chromium-getter material is merged with the existing interconnect structure by bonding it to the interconnect surface. This integration approach combines the structural function of the interconnect with the protective function of the getter material, reducing device complexity compared to adding separate components.
Solution Approach 2:
The interconnect structure is given multiple functions: it provides structural support and electrical connection as before, and additionally serves as a substrate for the chromium-getter material that protects against chromium contamination. This multi-functionality reduces the need for additional separate components, thereby reducing overall device complexity.
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 chromium-getter material effectively captures chromium vapors, slowing down cathode degradation and maintaining fuel cell performance by preventing chromium poisoning, as demonstrated by reduced voltage drops and extended runtime in tests.
Implementation Method 1
the chromium-getter material comprises a material that is configured to react with chromium to remove chromium species from chromium vapor
Implementation Method 2
the coated substrate is configured to remove chromium species from chromium vapor in the solid oxide fuel cell system before the chromium species can react with a cathode
Data Source
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AI summary
In some embodiments, a solid oxide fuel system is provided. The solid oxide fuel cell system may include a chromium-getter material. The chromium-getter material may react with chromium to remove chromium species from chromium vapor. The solid oxide fuel cell system may also include an inert substrate. The chromium-getter material may be coated onto the inert substrate. The coated substrate may remove chromium species from chromium vapor before the chromium species can react with a cathode in the solid oxide fuel cell system.