Metal-Supported SOFC Electrolyte Structure for Low-Temperature Densification
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Solution Overview
Problem
Conventional metal-supported solid oxide fuel cells (SOFCs) face durability issues due to high-temperature heat treatment, which can deteriorate the metal substrate and affect the electrode and electrolyte layers, making it difficult to achieve a dense electrolyte layer and robust SOFCs at low temperatures.
Innovation Solution
The electrochemical element features a metal substrate with through holes, an electrode layer covering the substrate, and an electrolyte layer with a configuration that encloses the electrode layer, providing enhanced robustness and gas leakage prevention, using a cermet electrode layer and zirconia-based electrolyte for improved durability and gas permeability, and employing low-temperature processing methods like aerosol deposition or flame gunning to form the electrolyte layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-temperature heat treatment (e.g., 1400°C sintering) is performed to obtain a dense electrolyte layer, then the electrolyte layer becomes dense and highly gastight, but the metal substrate deteriorates and element diffusion occurs, reducing durability
Solution Approach 1:
The patent applies low-temperature heat treatment (e.g., 900-1100°C) instead of conventional high-temperature sintering (1400°C) to form the electrolyte layer. This parameter change in treatment temperature prevents metal substrate deterioration and element diffusion while still achieving a dense electrolyte layer through the specific combination of low-temperature sintering and pressing treatment at optimized conditions.
2Reliability
If heat treatment temperature is lowered to preserve metal substrate integrity, then substrate deterioration is prevented, but it becomes difficult to form a dense electrolyte layer with good joint strength
Solution Approach 1:
The patent combines pressing treatment with low-temperature sintering treatment in a integrated process. The pressing treatment applies mechanical pressure to densify the electrolyte layer, while the subsequent low-temperature sintering (900-1100°C) bonds the particles. This combination of mechanical and thermal processes achieves dense electrolyte layer formation without requiring high-temperature treatment that would damage the metal substrate.
3Strength
If conventional high-temperature sintering is used to ensure robustness, then electrolyte layer density is achieved, but additional sealing structures are required due to substrate deterioration and gas leakage
Solution Approach 1:
The patent eliminates the need for additional sealing structures by successfully preventing gas leakage through the metal substrate. By using low-temperature sintering with pressing treatment, the metal substrate maintains its integrity without deterioration, and the electrolyte layer forms with good adhesion, creating a self-sealing structure that removes the requirement for separate sealing components.
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
This configuration allows for the formation of a dense electrolyte layer at low temperatures, enhancing the durability and robustness of the electrochemical element, reducing gas leakage, and eliminating the need for additional sealing structures, thereby improving the overall performance and longevity of the SOFCs.
Implementation Method 1
employing low-temperature processing methods like aerosol deposition or flame gunning to form the electrolyte layer
Implementation Method 2
employing low-temperature processing methods like aerosol deposition or flame gunning to form the electrolyte layer
Implementation Method 3
a dense electrolyte layer... reducing gas leakage
Data Source
Figure 1~2
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Figure 5~6
AI summary
Realized are an electrochemical element and a solid oxide fuel cell that have a dense electrolyte layer and that have excellent durability and robustness, and methods for producing the same. An electrochemical element includes: a metal substrate 2 having a plurality of through holes 21; an electrode layer 3 provided over a front face of the metal substrate 2; and an electrolyte layer 4 provided over the electrode layer 3, wherein the through holes 21 are provided passing through the front face and a back face of the metal substrate 2, the electrode layer 3 is provided in a region larger than a region, of the metal substrate 2, in which the through holes 21 are provided, and the electrolyte layer 4 has a first portion 41 coating the electrode layer 3, and a second portion 42 that is in contact with the front face of the metal substrate 2.