Cross-Flow Interconnect Flattening to Prevent SOFC Stress Cracks
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Solution Overview
Problem
Conventional fuel cell stacks face issues with non-uniform fuel distribution, reduced active area, and thermal stress cracks due to complex fuel manifolds and through-holes, leading to decreased performance and efficiency.
Innovation Solution
The use of cross-flow interconnects with integrated fuel inlets and outlets, coated with lanthanum strontium manganite (LSM) or (Mn, Co)3O4 spinel, and dielectric layers to prevent electrical shorting, along with a chromium-iron alloy for improved thermal expansion matching, enhances uniform fuel distribution and reduces thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional fuel manifolds and through-holes are used for fuel distribution, then fuel can be supplied to cells, but non-uniform fuel distribution and thermal stress cracks occur
Solution Approach 1:
The patent removes the conventional fuel manifold and through-holes from the interconnect structure. Instead, fuel is distributed through the gas flow separator plate which has fuel channels formed on its surface, eliminating the sources of non-uniform distribution and thermal stress concentration
Solution Approach 2:
The gas flow separator plate is designed with pre-formed fuel channels and recessed regions that guide fuel distribution before it reaches the cells. This preliminary structuring ensures uniform fuel delivery and prevents thermal stress cracks from forming
2Quantity of substance
If complex fuel manifolds are used, then fuel distribution is achieved, but active area is reduced
Solution Approach 1:
The patent combines the gas flow separator function and fuel distribution function into a single integrated plate structure. The gas flow separator plate simultaneously separates gases between cells and distributes fuel through its built-in channels, eliminating the need for separate manifolds and preserving active area
Solution Approach 2:
The gas flow separator plate performs multiple functions: it separates gas flows between adjacent cells, distributes fuel uniformly to cell inlets, and structurally supports the stack. This multi-functionality eliminates redundant components and maximizes active area
3Ease of operation
If through-holes are used in interconnects, then fuel flow is enabled, but thermal stress cracks develop
Solution Approach 1:
The patent eliminates through-holes from the interconnect structure entirely. Fuel flow is achieved through surface channels on the gas flow separator plate instead of penetrating holes, removing the stress concentration points that lead to thermal cracking
Solution Approach 2:
The gas flow separator plate acts as an intermediary structure that enables fuel flow through its channel network without requiring through-holes in the interconnect. This mediator structure distributes fuel uniformly while maintaining structural integrity under thermal stress
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 uniform fuel distribution, maximizes fuel cell active area, and minimizes thermal stress cracks, thereby improving the operational efficiency and yield of fuel cell stacks.
Implementation Method 1
coated with lanthanum strontium manganite (LSM) or (Mn, Co)3O4 spinel, and dielectric layers to prevent electrical shorting, along with a chromium-iron alloy for improved thermal expansion matching
Implementation Method 2
creep flattening the interconnect prior to placing the interconnect into the electrochemical cell stack
Data Source
AI summary
A method of making an interconnect for an electrochemical cell stack includes providing the interconnect, and creep flattening the interconnect prior to placing the interconnect into the electrochemical cell stack.