SOEC Interconnector Protective Film for Low Resistance and Cr Suppression

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing interconnectors for solid-oxide electrochemical cells face issues with high electrical resistance due to Cr2O3 oxide coating films, which degrade performance and increase resistance, and adhesiveness problems due to non-uniform protective films in complex shapes, especially when using stainless alloys with high chromium content.

Innovation Solution

A protective film composed of a spinel oxide and perovskite oxide with dispersed phases of rare earth elements and/or zirconium oxides is applied to the interconnector, enhancing adhesiveness and electrical conductivity while suppressing chromium vaporization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a stainless alloy with high chromium content is used as the interconnector base, then high-temperature resistance is improved, but electrical resistance increases due to Cr2O3 coating film formation

Engineering Contradiction:

Improvehigh-temperature resistanceVSAvoidelectrical resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

A protective film composed of spinel oxide or perovskite oxide is introduced as an intermediary layer between the chromium-containing interconnector base and the high-temperature environment. This protective film mediates the contradiction by providing oxidation resistance while maintaining electrical conductivity, preventing the formation of high-resistance Cr2O3 on the surface.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The interconnector employs a composite structure combining a chromium-containing stainless alloy base with a spinel or perovskite oxide protective film. This composite material approach allows the system to simultaneously achieve high-temperature stability from the chromium base and low electrical resistance from the conductive oxide film.

Inventive Principle:

Principle #40Composite materials

2Loss of substance

If a dense protective film is applied to suppress Cr evaporation, then Cr evaporation suppression is improved, but adhesiveness decreases due to peeling under thermal cycling

Engineering Contradiction:

ImproveCr evaporation suppressionVSAvoidadhesiveness

Core Design Contradiction:

Loss of substanceVSStrength

Solution Approach 1:

The protective film composition parameters are optimized to achieve a balance between density and thermal expansion characteristics. By adjusting the spinel or perovskite oxide composition, the film maintains sufficient density for Cr evaporation suppression while achieving thermal expansion compatibility with the substrate, preventing adhesion failure during thermal cycling.

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If a protective film is applied to reduce electrical resistance, then electrical conduction is improved, but workability decreases due to difficulty in forming uniform films on complex shapes

Engineering Contradiction:

Improveelectrical conductionVSAvoidworkability

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The protective film utilizes a controlled porous structure characteristic of spinel and perovskite oxides. This porous morphology allows the film to conform to complex interconnector geometries while maintaining adequate electrical conductivity through the conductive oxide network, thus improving workability without sacrificing electrical performance.

Inventive Principle:

Principle #31Porous materials

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 protective film improves adhesiveness and reduces electrical resistance, ensuring stable performance and structural integrity of the electrochemical cell stack under high-temperature conditions.

Implementation Method 1

the protective film includes a protective film body containing at least one selected from a spinel oxide and a perovskite oxide, and dispersed phases scattered in the protective film body and containing an oxide of at least one element selected from the group consisting of rare earth elements and zirconium

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The Cr evaporation suppression is a function to suppress the evaporation of Cr contained in the interconnector for the solid-oxide electrochemical cell stack, as Cr vaporizes under high-temperature operating conditions

Methodology Applied

Scientific EffectEvaporation suppression: Evaporation

Implementation Method 3

The adhesiveness is a function to prevent the protective film from peeling off due to repetition of temperature rise and fall between high temperature and room temperature because operating temperature of the solid-oxide electrochemical cell is a high temperature of 600° C. or higher

Methodology Applied

Scientific EffectThermal expansion compatibility: Thermal Expansion

Data Source

PatentUS12609328B2Interconnector for solid-oxide electrochemical cell stack and solid-oxide electrochemical cell stack

Publication Date: 2026.04.21 TOSHIBA ENERGY SYST & SOLUTIONS CORP

AI summary

An interconnector for a solid-oxide electrochemical cell stack of the embodiment includes: a metal base containing an iron-based alloy containing chromium; and a protective film provided on a surface of the metal base. The protective film includes a protective film body containing at least one selected from a spinel oxide and a perovskite oxide, and dispersed phases scattered in the protective film body and containing an oxide of at least one element selected from the group consisting of rare earth elements and zirconium.