SOFC Fe-Cr Alloy Composition to Suppress Chromium Volatilization

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Solution Overview

Problem

Conventional metal materials used in electrochemical devices, such as Crofer 22 APU, suffer from Cr volatilization, which poisons other components and reduces durability and performance.

Innovation Solution

Employing a Fe-Cr based alloy with specific Ti and Cu content, along with a metal oxide thin layer, to stabilize the alloy and suppress Cr volatilization, while maintaining thermal expansion compatibility with other layers and reducing electric resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a button cell or coin-shaped electrochemical device is used, then the device can be integrated into jewelry or accessories, but the device generates harmful electromagnetic signals that can be detected by scanners

Engineering Contradiction:
Improveintegration into jewelryVSAvoidelectromagnetic signal detection
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies magnetic shielding materials (such as mu-metal or ferrite) around the electrochemical device to absorb and redirect electromagnetic signals. This converts the harmful detectable signal into a contained magnetic field that protects against detection by scanners while maintaining the device's functionality in jewelry applications

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Device complexity

If conventional electrochemical devices are used, then the device structure is simple, but the device is prone to leakage and short circuits

Engineering Contradiction:
Improvedevice structureVSAvoidleakage resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a nested sealing structure where an inner seal member is placed within an outer seal member, creating multiple barriers against leakage. The inner seal member directly contacts the electrolyte while the outer seal member provides additional protection, and both are contained within the device housing. This multi-layer nested approach significantly reduces leakage and short circuit risks without substantially increasing device complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent incorporates seal members and gaskets made of elastomeric or polymeric materials between the electrochemical device and the housing before assembly. These pre-installed cushioning elements compensate for manufacturing tolerances and prevent leakage by creating a compliant seal that accommodates minor dimensional variations, thereby improving reliability without requiring complex precision manufacturing

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Volume of moving object

If the device is designed for jewelry integration, then the device size is reduced, but the device may cause skin irritation or discomfort

Engineering Contradiction:
Improvedevice sizeVSAvoidskin irritation
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent employs flexible biocompatible coatings or thin film barriers on the outer surface of the device that contacts the skin. These flexible shells provide a protective interface that prevents direct contact between skin and potential irritants while maintaining the small size required for jewelry integration. The thin film structure conforms to the device's compact geometry and provides continuous protection during wear

Inventive Principle:
Principle #30Flexible shells and thin films

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

Enhances durability, reliability, and performance by preventing Cr volatilization, reducing electric resistance, and maintaining thermal expansion compatibility, thus achieving a low-cost electrochemical device.

Implementation Method 1

a solid oxide fuel cell stack and a reformer... The solid oxide fuel cell stack includes a first end and a second end opposite each other

Methodology Applied
Scientific EffectElectrochemical reactions: Fuel Cell

Implementation Method 2

the reformer is configured to receive a hydrocarbon... convert the hydrocarbon into a reformed gas

Methodology Applied
Scientific EffectReforming reactions: Chemical Transport Reactions

Data Source

PatentEP3605695B1Electrochemical device, energy system, and solid oxide fuel cell
Publication Date: 2026.04.08 OSAKA GAS CO LTD
  • EP3605695B1 patent drawingFigure 1~2
  • EP3605695B1 patent drawingFigure 3
  • EP3605695B1 patent drawingFigure 4

AI summary

Provided are a low-cost electrochemical device and the like that have both durability and high performance as well as excellent reliability. The electrochemical device includes at least one metal material, and the metal material is made of a Fe-Cr alloy that contains Ti in an amount of more than 0.10 mass% and 1.0 mass% or less.