Solid Oxide Fuel Cell Electrolyte Sheet Rounded Surface
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Solution Overview
Problem
Conventional methods for roughening electrolyte sheets for solid oxide fuel cells often result in uneven surface roughness, leading to mechanical weakness, increased risk of cracking, and reduced reliability due to acutely angled surfaces, which compromise the strength and adhesion of the electrolyte sheets.
Innovation Solution
The electrolyte sheet features concaves or convexes with rounded corners and specific dimensions, formed using a stamper with corresponding shapes, to enhance mechanical strength and adhesion, while preventing cracks and improving surface uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If blasting or etching is used to roughen the electrolyte sheet surface, then the surface roughness is increased to improve adhesion, but the surface becomes uneven with acutely angled features that create mechanical weakness and increase cracking risk
Solution Approach 1:
The invention replaces the conventional blasting or etching method that creates acutely angled rough surfaces with a pressing method using a stamper having convexes with rounded corners (curvature radius of 0.1 μm or more). This curvature principle eliminates stress concentration points while maintaining surface roughness for adhesion, thereby resolving the contradiction between adhesion strength and mechanical strength
2Length of moving object
If the electrolyte sheet is made thinner to reduce cell size, then the cell dimensions are reduced, but the sheet becomes more prone to cracking and warping due to stresses from roughening processes
Solution Approach 1:
By using a stamper with convexes having rounded corners (curvature radius ≥ 0.1 μm) instead of acutely angled surfaces from blasting, the invention eliminates stress concentration points that would cause cracking in thin sheets. This allows production of thinner electrolyte sheets (reducing cell size) while maintaining sheet stability and preventing warping
3Ease of manufacture
If conventional pressing with flat or sharply angled surfaces is used, then the manufacturing process is simple, but the resulting electrolyte sheet has poor adhesion and increased cracking risk due to acutely angled surfaces
Solution Approach 1:
The invention modifies the stamper design to include convexes with rounded corners (curvature radius of 0.1 μm or more) rather than flat or sharply angled surfaces. This simple geometric modification to the pressing tool simultaneously improves adhesion (through controlled roughness) and strength (by eliminating stress concentration points), while maintaining ease of manufacture through the simplicity of the pressing process
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(b)
Figure 3
AI summary
An electrolyte sheet for solid oxide fuel batteries with mechanical strength characteristics is proposed. These characteristics may include a high and stable average value of strength, Weibull coefficient, and a high adhesion to an electrode formed on a surface thereof and hence inhibits the electrode from interfacial separation from the electrolyte sheet. The electrolyte sheet for solid oxide fuel batteries is characterized by having a plurality of concaves and/or convexes on at least one surface thereof, the concaves and convexes having base faces which are circular or elliptic or are a rounded polygon in which the vertexes have a curved shape with a curvature radius of 0.1 µm or larger and/or the concaves and convexes having a three-dimensional shape which is semispherical or semiellipsoidal or is a polyhedron in which the vertexes and the edges have a curved cross-sectional shape having a curvature radius of 0.1 µm or larger.