Mn-Co-Y Spinel Coating for SOFC Interconnect Oxide Suppression

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Solid oxide fuel cells face performance degradation due to the formation of insulating oxide layers on metal interconnects, leading to high electrical resistance and reduced catalyst activity, particularly when using Fe-Cr-based alloys in high-temperature oxidizing environments.

Innovation Solution

A ceramic protective layer with a spinel structure, represented by Mn1.5-0.5(x1+x2)Co1.5-0.5(x1+x2)Cu x1 Y x2 O4, is applied to the conductive substrate, suppressing oxide layer growth and maintaining thermal compatibility with the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a Fe-Cr-based metal is used as an interconnect, then processability and thermal compatibility are improved, but catalyst activity is reduced and contact resistance increases due to chromium oxidation

Engineering Contradiction:
ImproveprocessabilityVSAvoidcatalyst activity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

A Mn-Co-Y spinel coating layer is applied as an intermediary between the Fe-Cr interconnect and the external environment. This coating prevents direct oxidation of chromium while maintaining thermal compatibility, thereby preserving catalyst activity and reducing contact resistance without sacrificing the ease of manufacture of the Fe-Cr substrate

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The interconnect system becomes a composite structure combining the Fe-Cr metal substrate with a Mn-Co-Y spinel protective coating. This composite approach allows the metal to provide mechanical strength and thermal compatibility while the ceramic coating prevents harmful oxidation, resolving the contradiction between ease of manufacture and reliability

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If a Fe-Cr-based metal is used as an interconnect, then thermal compatibility with electrode materials is improved, but electrical conductivity deteriorates due to non-conductive oxide formation

Engineering Contradiction:
Improvethermal compatibilityVSAvoidelectrical conductivity
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The Mn-Co-Y spinel coating acts as a mediator that maintains thermal compatibility with electrode materials while preventing the formation of non-conductive chromium oxides. The spinel structure itself provides a conductive pathway, thereby preserving electrical conductivity without compromising thermal compatibility

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If conventional coating methods (electroplating, sputtering, plasma spray) are used, then surface conductivity is improved, but manufacturing cost and process complexity increase

Engineering Contradiction:
Improvesurface conductivityVSAvoidcoating process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the parameters of the coating process by using a specific Mn-Co-Y spinel composition and controlled atmosphere heat treatment instead of conventional electroplating, sputtering, or plasma spray methods. This parameter change achieves the desired surface conductivity while simplifying the manufacturing process and reducing costs

Inventive Principle:
Principle #35Parameter changes

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 solution effectively prevents the decline in electrical properties and thermal performance of the interconnect, maintaining high conductivity and stability over long periods at high temperatures.

Implementation Method 1

A ceramic protective layer with a spinel structure, represented by Mn1.5-0.5(x1+x2)Co1.5-0.5(x1+x2)Cu x1 Y x2 O4, is applied to the conductive substrate, suppressing oxide layer growth

Methodology Applied
Scientific EffectProtective coating: Coatings

Implementation Method 2

maintaining thermal compatibility with the substrate

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3678242B1Connecting material for solid oxide fuel cell, manufacturing method therefor, and solid oxide fuel cell
Publication Date: 2023.02.15 LG CHEM LTD
  • EP3678242B1 patent drawingFigure 1~2
  • EP3678242B1 patent drawingFigure 3~4
  • EP3678242B1 patent drawingFigure 5

AI summary

The present specification relates to an interconnect for a solid oxide fuel cell, a method for preparing the same, and a solid oxide fuel cell.