Stereostructure with Controlled Void Ratio Zones
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Solution Overview
Problem
Stereostructures with high surface expansion ratios for carrying functional materials like solid electrolytes or catalysts face challenges in maintaining mechanical strength due to excessive void formation, which compromises their structural integrity and surface area enhancement.
Innovation Solution
A stereostructure design featuring a core portion with a porous portion around it, where the void ratio per unit area is controlled between 15% and 80% in specific regions, ensuring a balance between surface area expansion and mechanical strength through strategic etching or material deposition techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the stereostructure includes many voids to increase surface expansion ratio, then the surface area for carrying functional materials increases, but the mechanical strength at portions where voids exist becomes insufficient
Solution Approach 1:
The patent applies local quality by creating different void ratio zones within the porous layer: an outer region with higher void ratios (0.6-0.9) for surface area expansion, and an inner region with lower void ratios (0.3-0.6) for maintaining mechanical strength. This spatial differentiation of porosity allows simultaneous optimization of both surface area and structural integrity.
Solution Approach 2:
The patent segments the porous layer into distinct radial zones with different void ratio characteristics. The porous layer is divided into an outer porous region and an inner region separated by a specific boundary distance from the substrate, allowing independent optimization of void ratios in each zone to balance surface area expansion and mechanical strength.
2Area of stationary object
If voids are formed in order from an outer peripheral portion toward a central portion by etching, then more voids are formed approaching the central portion, but the portion where voids are formed excessively has insufficient mechanical strength
Solution Approach 1:
The patent implements local quality control by specifying different void ratio ranges for different radial positions within the porous layer. The outer region (closer to substrate) maintains lower void ratios (0.3-0.6) to provide structural support, while the inner region (farther from substrate) allows higher void ratios (0.6-0.9) to maximize surface area for functional material carrying.
Solution Approach 2:
The patent applies preliminary action by pre-defining the void ratio distribution profile before functional material deposition. The porous layer is engineered with a specific void ratio gradient during manufacturing, ensuring that the structural framework is established with appropriate mechanical strength before the functional materials are introduced.
3Area of stationary object
If voids are formed excessively in the central portion, then voids become connected forming large voids, but it becomes difficult to obtain a high surface expansion ratio
Solution Approach 1:
The patent uses local quality by controlling void ratio distribution radially across the porous layer. The outer region maintains moderate void ratios (0.3-0.6) to prevent void coalescence and maintain fine pore structure, while the inner region permits higher void ratios (0.6-0.9) to achieve surface area expansion without compromising overall structural integrity.
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 design achieves a high surface expansion ratio while maintaining sufficient mechanical strength, preventing excessive void formation and connectivity, thus enhancing the structural integrity and performance in applications like electrolytic capacitors and catalyst carriers.
Implementation Method 1
when voids are formed in order from an outer peripheral portion toward a central portion of the stereostructure by etching
Data Source
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AI summary
A stereostructure (11) includes a core portion (12), and a porous portion (13) located around the core portion (12). The porous portion (13) located inside a position (11a) which is inside from an outer edge (13a) of the porous portion (13) by 3/20 of a diameter of the stereostructure (11) in an arbitrary cross section of the stereostructure (11) has a void ratio per unit area of less than or equal to 80%.