Electrochemical Cell Stack End Plate for High-Temperature Sealing
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Solution Overview
Problem
Existing electrochemical cell systems face challenges in maintaining a fluid seal and transferring electrical energy while operating at high temperatures, particularly in fuel cell stacks, due to the need for high compression loads and expensive creep-resistant materials to prevent seal failure.
Innovation Solution
The design incorporates a compression mechanism between base and top plates to maintain a fluidic seal and electrical contact, allowing electrical studs to pass through without requiring tension, thus eliminating the need for creep-resistant materials and reducing the risk of seal failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If electrical studs pass through the vessel to transfer electrical energy, then electrical energy transfer is enabled, but fluid seal integrity is compromised
Solution Approach 1:
The electrical stud is divided into separate functional sections: an electrical contact portion that interfaces with the end plate, and a seal portion that interfaces with the vessel. This segmentation allows different materials and functions to be optimized independently - the electrical portion for conductivity and the seal portion for fluid tightness.
Solution Approach 2:
A separate fluid seal member (gasket or sealing ring) is introduced as an intermediary component between the electrical stud and the vessel. This mediator maintains the fluid seal while allowing the electrical stud to pass through, decoupling the electrical function from the sealing function.
2Reliability
If high compression loads are applied to maintain fluid seal, then seal reliability improves, but system complexity and material requirements increase
Solution Approach 1:
The compression mechanism is merged with the existing end plate assembly that is already part of the fuel cell stack structure. The end plate serves dual functions: electrical connection and compression application, eliminating the need for separate compression devices.
Solution Approach 2:
The fuel cell stack's own operational compression (applied during normal operation to maintain electrical contact between cells) is utilized to simultaneously maintain the fluid seal around the electrical stud, rather than requiring an independent compression system.
3Reliability
If creep-resistant materials are used for electrical studs, then seal reliability under high temperature improves, but manufacturing cost increases
Solution Approach 1:
A separate fluid seal member (gasket or sealing ring) made of creep-resistant material is introduced as an intermediary between the electrical stud and the vessel. This allows the electrical stud itself to be made from standard, lower-cost materials while the seal member handles the high-temperature creep resistance requirement.
Solution Approach 2:
The fluid seal member is designed as a replaceable, lower-cost component that can be manufactured from standard materials and replaced if needed, rather than requiring the expensive creep-resistant materials for the entire electrical stud assembly.
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 solution effectively maintains a fluid seal and facilitates efficient electrical energy transfer across a wide temperature range, reducing the risk of system failure and operational costs by using standard materials for the electrical studs.
Implementation Method 1
a fluidic seal is maintained by the compression means between the base portion and the respective one of the base plate and top plate
Implementation Method 2
at least one of the electrical end plates is connected or integrally formed with, and in electrical contact with, an electrical stud that extends from a base portion of the at least one electrical end plate and passes through an opening in one of the base plate and top plate to form an electrical terminal
Data Source
AI summary
An electrochemical cell assembly (1400) comprising a base plate (308) and a top plate (303) between which a stack of planar cell units (306) and at least one electrical end plate (1402, 1407) are disposed in compression. The electrical end plate (1402, 1407) comprises a two-layer construction in which a first layer (1416, 1419) and a second layer (1417, 1420) formed of different respective materials are permanently connected together to form a single conductive body. The first layer (1416, 1419) of the electrical end plate (1402, 1407) is electrically connected to an external electrical terminal (301, 505) of the cell assembly, and the second layer (1417, 1420) of the electrical end plate (1402, 1407) has an outwardly facing side having a first electrically conductive ceramic layer (1418, 1824) bonded thereto that is in face-to-face abutment with, and in electrical contact with, an adjacent cell unit (306).