Fuel Cell Stack Composite Sealing for Leakage Prevention
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Solution Overview
Problem
Existing fuel cell stacks face challenges with gas leakage due to the limitations of compression seal members, which fail to completely prevent leakage, and glass or ceramic seal members that can crack under stress or deform at high temperatures, affecting power generation efficiency and maintaining electrical connections.
Innovation Solution
A fuel cell stack design that combines compression seal members and glass seal members, where the glass seal members are sandwiched between components to prevent gas leakage, with the compression seal members restraining excessive force and deformation, ensuring stable electrical connections and high sealing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compression seal members are used to provide gas sealing, then sealing is provided at the interfaces between components, but gas leakage cannot be completely prevented and the seal members may deform under excessive force
Solution Approach 1:
The patent uses a composite sealing structure combining a compression seal member (first seal member) and a glass seal member (second seal member). The compression seal member provides initial sealing and compressibility, while the glass seal member provides high-temperature stability and crack resistance. This composite approach resolves the contradiction by combining materials with complementary properties to achieve both sealing reliability and structural strength.
Solution Approach 2:
The glass seal member is disposed to surround the compression seal member, creating a nested configuration. The compression seal member is positioned inside the glass seal member's sealing region, allowing the softer compression seal to deform and fill gaps while the harder glass seal member provides outer structural support and prevents excessive deformation. This nested arrangement enables both seal members to work synergistically.
2Reliability
If glass or ceramic seal members are used to prevent gas leakage, then high sealing performance is obtained, but the seal members may crack when strong force is applied
Solution Approach 1:
The compression seal member acts as an intermediary between the external loading forces and the glass seal member. It absorbs and distributes the compressive forces, preventing concentrated stresses that would cause the glass seal member to crack. The compression seal member mediates the mechanical stress, allowing the glass seal member to maintain its high sealing performance without suffering from stress-induced cracking.
3Reliability
If glass seal members are used in high temperature environments, then sealing performance is maintained, but the glass softens and deforms causing thickness changes
Solution Approach 1:
The patent selects glass materials with specific softening points higher than the fuel cell operating temperature. By changing the material parameter (softening point) to be sufficiently high, the glass seal member maintains its dimensional stability and resistance to deformation at operating temperatures while still providing effective sealing. The compression seal member further compensates for any minor thermal deformation through its elastic properties.
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
The combination effectively prevents gas leakage, maintaining high power generation efficiency and reducing the need for aftertreatment of leakage gas, while ensuring stable electrical connections and durability under thermal cycles.
Implementation Method 1
a plurality of fuel cells 3 are assembled in a state in which they are pressed in a stacking direction
Implementation Method 2
the glass seal member 93 is joined to the separator 47 and the interconnector 43
Implementation Method 3
the compression seal member 91 restrains an excessive force
Data Source
AI summary
A flat-plate-type fuel cell stack including a plurality of plate-shaped stacked fuel cells each including an electrolyte layer, an anode, and a cathode. The fuel cell stack includes at least one of a fuel manifold communicating with a space adjacent to the anode and an oxidant manifold communicating with a space adjacent to the cathode. A compression seal member and a glass seal member are disposed around the at least one manifold.