Solid Oxide Fuel Cell Intermediate Layer for Low-Resistance Bonding
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Solution Overview
Problem
Fuel cells face inefficiencies due to the high electrical resistance caused by the reaction between the solid electrolyte layer and the air electrode layer, leading to reduced power generation efficiency, particularly due to the thick second intermediate layer with high Ce and Zr content.
Innovation Solution
Incorporating a CeO2-based intermediate layer with a rare earth element other than Ce, featuring a first and second intermediate layer configuration where the second intermediate layer has a greater thickness at the outer peripheral portion than at the center, reducing electrical resistance and enhancing bonding between the solid electrolyte and air electrode layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a thick second intermediate layer with high Ce and Zr content is used to enhance bonding between the solid electrolyte layer and air electrode layer, then bonding strength is improved, but electrical resistance increases leading to reduced power generation efficiency
Solution Approach 1:
The patent applies local quality by creating a non-uniform thickness distribution of the second intermediate layer. Specifically, the layer is designed to be thicker at the outer peripheral portion and thinner at the central portion, allowing different regions to serve different functions: the thicker outer region provides enhanced bonding strength and stress relief, while the thinner central region minimizes electrical resistance and maintains high power generation efficiency in the active area.
2Reliability
If a thick second intermediate layer is used to prevent peeling at the interface, then reliability is improved, but electrical resistance increases reducing power output
Solution Approach 1:
The patent implements local quality by spatially varying the thickness of the second intermediate layer. The outer peripheral portion has greater thickness to provide mechanical stability and prevent peeling at the interface, while the central portion has reduced thickness to minimize electrical resistance and maintain high power generation efficiency in the electrochemically active region.
3Duration of action of stationary object
If a uniform thick intermediate layer is used to reduce stress at the interface, then durability is improved, but electrical resistance increases leading to energy loss
Solution Approach 1:
The patent applies local quality by designing the second intermediate layer with non-uniform thickness. The outer peripheral portion is made thicker to effectively reduce and distribute stress at the interface, improving durability and preventing peeling. Meanwhile, the central portion is made thinner to reduce electrical resistance and minimize energy loss in the region where electrochemical reactions occur.
Data Source
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AI summary
A cell (1) includes an element portion including a first electrode layer (3), a solid electrolyte layer (4) that contains Zr and that is located above the first electrode layer (3), an intermediate layer (8) that contains CeO2 containing a rare earth element other than Ce and that is located above the solid electrolyte layer (4), and a second electrode layer (5) located above the intermediate layer (8). The intermediate layer (8) includes a first intermediate layer (8a) and a second intermediate layer (8b) that contains Zr and Ce and that is located at at least a portion between the first intermediate layer (8a) and the solid electrolyte layer (4). In a plan view from the second electrode layer (5), the second intermediate layer (8b) located at an outer peripheral portion of the intermediate layer (8) includes a portion with a thickness greater than the second intermediate layer (8b) overlapping a center of the second electrode layer (5). A cell stack device (13), a module (11), and a module housing device (21) include a plurality of the cells (1).