SOEC/SOFC Stack Interconnector Welding for Stable Gas Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-temperature solid oxide electrolyzer (SOEC) and fuel cell (SOFC) stacks face challenges in achieving stable electrical contact, proper gas distribution, and efficient gas compartment separation, leading to inefficiencies and potential damage from hot spots and gas recombination.
Innovation Solution
A method involving spot welding a metallic coating layer, such as a nickel grid, onto interconnectors with a specific adhesive composition to secure electrochemical cells, combined with ceramic contact layers, ensures stable assembly and rigid structure, enhancing electrical contact and gas distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metallic coating layer is spot-welded onto the interconnector to form a contact layer, then electrical contact stability is improved, but the assembly complexity and manufacturing difficulty increase
Solution Approach 1:
The metallic coating layer is applied to the interconnector surface before assembly, and spot-welding is performed during the manufacturing process to pre-establish reliable electrical contacts. This preliminary action ensures that electrical contact stability is achieved before the stack operates, preventing contact failures during service.
Solution Approach 2:
The metallic coating layer acts as an intermediary between the interconnector and the electrochemical cell, providing a dedicated contact interface that ensures stable electrical connection while isolating the bulk interconnector material from direct contact requirements.
2Stability of the object's composition
If an adhesive is used to fix the electrochemical cell to the interconnector, then cell stability and position fixation are improved, but residue formation and potential degradation increase
Solution Approach 1:
The adhesive composition is specifically formulated with controlled parameters including polyvinyl butyral content (5-50% by mass), terpineol content (5-50% by mass), and ethanol content (5-95% by mass). These parameter optimizations ensure the adhesive provides sufficient bonding strength while minimizing residue formation that could cause degradation.
Solution Approach 2:
The adhesive is a composite material combining polyvinyl butyral (providing bonding strength), terpineol (acting as a plasticizer and solvent), and ethanol (serving as a volatile carrier). This composite formulation achieves the desired balance between cell stability and residue minimization.
3Reliability
If the adhesive is deposited around the periphery of the coating layer outside the active area, then gas distribution is improved by avoiding active zone contamination, but the bonding area and attachment strength are reduced
Solution Approach 1:
The adhesive is applied with spatially varying properties: it is deposited around the periphery of the coating layer outside the active area, creating a localized bonding zone that does not interfere with gas distribution channels while still providing sufficient attachment strength through optimized peripheral bonding.
Solution Approach 2:
The interconnector design incorporates contact ribs that replicate the gas distribution channel pattern, allowing the adhesive to be positioned in non-active peripheral zones while maintaining proper gas flow paths through the replicated rib structure.
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 method improves the stability and efficiency of SOEC/SOFC stacks by preventing cell movement and residue formation, ensuring optimal electrical contact and gas distribution, thereby increasing production efficiency and reducing degradation.
Implementation Method 1
spot welding the metallic coating layer on the first face of the interconnector to allow its fixing
Implementation Method 2
depositing an adhesive around the periphery of the coating layer (GN), outside the active area and away from the gas supplies, intended to fix the electrochemical cell (1)
Implementation Method 3
each interconnector having two main flat faces, a second face of the two main flat faces comprising a thick ceramic coating layer, forming a contact layer with an electrochemical cell
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates mainly to a method for producing a SOEC/SOFC-type solid oxide stack operating at high temperature, comprising a plurality of electrochemical cells each formed by a cathode, an anode and an electrolyte inserted between the cathode and the anode, and a plurality of metal interconnectors each arranged between two adjacent electrochemical cells, each interconnector having two main flat faces, a first face (P1) of the two main flat faces comprising a metal coating layer (GN) in the form of a grid forming a contact layer with an electrochemical cell, the method comprising the step of spot-welding (S) the metal coating layer (GN) onto the first face (P1) of the interconnector in order to allow the attachment thereof.