Laminated SOFC Anode-Electrolyte Structure for Thin Electrolyte Cracking
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Solution Overview
Problem
Thinner electrolytes in solid oxide fuel cells (SOFCs) are prone to cracking due to stress from anode firing and thermal cycling, which increases electrical resistivity and reduces cell performance.
Innovation Solution
The electrolyte and anode precursor layers are formed separately and laminated together without direct contact, then sintered as a composite to reduce stress-induced cracking, allowing for a thickness of 100 microns or less, and controlled porosity is achieved through tape casting and hot isostatic pressing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the electrolyte thickness is reduced to decrease electrical resistivity, then electrical performance is improved, but the electrolyte becomes more prone to cracking under stress
Solution Approach 1:
The electrolyte and anode layers are merged into a single laminated composite structure formed by co-sintering precursor layers. This integration ensures perfect interfacial bonding and stress distribution across the interface, preventing crack propagation that would occur in separately assembled thin electrolyte structures.
Solution Approach 2:
The invention uses a composite laminate structure where the electrolyte is bonded to anode layers with different thermal and mechanical properties. This composite structure distributes stress more evenly during thermal cycling and firing processes, allowing the electrolyte to be made thinner without cracking.
2Productivity
If the electrolyte is made thinner to improve cell performance, then electrical conductance increases, but stress from anode firing causes more cracking
Solution Approach 1:
The electrolyte and anode are combined into a single laminated green composite formed by co-sintering precursor layers. This ensures perfect interfacial bonding and stress distribution, allowing thin electrolytes to withstand firing stress without cracking.
Solution Approach 2:
The invention changes the processing parameters by co-sintering the electrolyte and anode precursors together at controlled temperatures. This parameter change allows the formation of a bonded interface before the anode undergoes significant volume change during firing, preventing stress-induced cracking in thin electrolytes.
3Ease of manufacture
If separate formation and assembly of electrolyte and anode layers is used, then manufacturing flexibility is maintained, but interface bonding quality and stress resistance deteriorate
Solution Approach 1:
The electrolyte and anode precursors are formed separately with controlled porosity and composition, then stacked and co-sintered together. This preliminary formation of separate layers with optimized properties, followed by intimate bonding during co-sintering, achieves both manufacturing flexibility and high interface bonding quality.
Solution Approach 2:
The separate precursor layers are combined into a laminated composite structure through co-sintering. This composite approach allows each layer to be optimized independently during precursor formation, while the sintering process creates strong interfacial bonding with stress distribution capabilities.
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 method decreases electrolyte cracking while reducing electrical resistivity, enhancing the SOFC's performance and durability by maintaining a thin electrolyte structure without significant damage.
Implementation Method 1
laminating the at least one anode precursor layer and the ceramic electrolyte precursor layer
Implementation Method 2
stacking the formed at least one anode precursor layer in contact with a first side of the ceramic electrolyte precursor layer, laminating the at least one anode precursor layer and the ceramic electrolyte precursor layer
Data Source
AI summary
A solid oxide fuel cell (SOFC) includes a ceramic electrolyte having a thickness of 100 microns or less, an anode laminated to a first side of the electrolyte, and a cathode located on a second side of the electrolyte opposite to the first side.