SOFC Interconnector Ceramic Layering to Prevent Delamination
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Solution Overview
Problem
Current interconnectors for solid oxide fuel cells (SOFCs) and high-temperature electrolysis (HTE) face challenges such as high area-specific resistance, corrosion, and high production costs due to imperfections in the manufacturing process, particularly in creating conductive ceramic layers that prevent chromium evaporation and ensure good electrical contact, leading to significant scrap rates during mass production.
Innovation Solution
A process involving tape casting, localized material removal, and hot pressing with laser ablation to create a thick ceramic layer on a chromia-forming metal alloy substrate, which reduces bubble formation and delamination, allowing for precise channel formation and improved adhesion, thereby reducing production time and scrap rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hot pressing is used to create ceramic layers on interconnectors, then electrical contact is improved, but bubble formation and delamination occur leading to high scrap rates
Solution Approach 1:
The patent applies preliminary action by creating a roughened substrate surface through sandblasting or acid etching before applying the ceramic slurry. This pre-treatment ensures better adhesion and prevents bubble formation during subsequent hot pressing, eliminating the need for rework and reducing scrap rates while maintaining reliable electrical contact.
Solution Approach 2:
The patent implements local quality by applying ceramic slurry selectively to specific areas of the interconnector surface rather than uniformly coating the entire surface. This targeted application reduces material waste, minimizes delamination risks in non-critical areas, and maintains precise electrical contact where needed, thereby improving manufacturing precision.
2Object-affected harmful factors
If thick ceramic layers are applied to prevent chromium evaporation, then corrosion resistance is improved, but production time increases due to longer drying and firing cycles
Solution Approach 1:
The patent applies parameter changes by optimizing the composition of the ceramic slurry to include specific binders and solvents that enable faster drying and lower-temperature firing. This reduces the thick ceramic layer's processing time while maintaining its corrosion-resistant properties, thus improving production efficiency without sacrificing protection against chromium evaporation.
Solution Approach 2:
The patent uses composite materials by formulating the ceramic layer as a composite of protective ceramics with organic binders and plasticizers. This composite structure allows the thick layer to be applied in a slurry form that dries quickly and fires at reduced temperatures, cutting production time while preserving the corrosion resistance needed to prevent chromium evaporation in high-temperature environments.
3Reliability
If multiple coating layers are applied to ensure durability, then reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent merges multiple functions into a single ceramic coating layer that simultaneously provides corrosion resistance, electrical conductivity, and mechanical protection. This multi-functional coating eliminates the need for separate layers for each function, reducing device complexity and manufacturing steps while maintaining high reliability and durability of the interconnector.
Solution Approach 2:
The ceramic slurry composition is designed to be universal, serving multiple purposes: it protects against corrosion, ensures electrical contact, and provides mechanical strength. This multi-functional approach replaces multiple specialized coating layers, simplifying the manufacturing process and reducing overall device complexity while enhancing the durability of the interconnector assembly.
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 process significantly reduces production time and scrap rates, achieving a viable industrial-scale solution with low material waste and improved electrical contact, enhancing the durability and efficiency of interconnectors for SOFCs and HTE systems.
Implementation Method 1
hot pressing the green thick ceramic layer tape
Implementation Method 2
localized removal at one or more locations, of material of the tape-cast thick ceramic layer
Data Source
AI summary
A process for preparing a component, which may constitute an interconnector for a fuel cell (SOFC) or a high-temperature electrolyser (HTE), may include: (a) preparing a substrate made of metal alloy, the base element of which is iron (Fe) or nickel (Ni), the substrate having two main flat faces; (b) tape casting a thick ceramic layer; (c) localized removal at one or more locations, of material of the tape-cast thick ceramic layer; (d) hot pressing the green thick ceramic layer tape; and (e) grooving the thick ceramic layer so as to delimit channels that are suitable for distributing and/or collecting gases. A component may be obtained from such a process.