Fuel Cell Unit Cell Elastomer Frame Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional elastomeric cell frames for fuel cells face issues with airtightness and gas flow path integrity when laminated with metal separators, leading to compression and blockage of inlet and outlet areas, and undesired deformation during lamination.
Innovation Solution
A unit cell design incorporating a sheet-shaped elastomer frame thermally bonded to a Membrane-Electrode Assembly with a metal separator, featuring reaction surface through-holes and frame manifold through-holes, along with protrusion seals and flow path parts to maintain airtightness and secure gas flow paths, where the elastomer frame and separator are designed with specific height and width differences to prevent deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an elastomer frame is used to bond the Membrane-Electrode Assembly and gas diffusion layer, then the manufacturing process is simplified and adhesive members are eliminated, but the elastomer frame is compressed by the metal separator during lamination, narrowing or blocking the inlet and outlet areas
Solution Approach 1:
The elastomer frame is segmented into multiple functional regions: a rigid support portion that maintains structural integrity and prevents compression deformation, and a flexible sealing portion that provides airtightness while accommodating compression. This segmentation allows different parts of the frame to perform different functions - the rigid portion resists compression to maintain gas flow paths, while the flexible portion ensures sealing between components.
Solution Approach 2:
The elastomer frame's physical parameters are optimized by controlling the ratio of rigid to flexible portions and adjusting the material properties of the elastomer. The rigid support portion has higher stiffness to resist compression, while the flexible sealing portion has lower stiffness to accommodate deformation. This parameter optimization ensures that during lamination, the frame maintains its gas flow path geometry while still providing effective sealing.
2Reliability
If the elastomer frame is compressed during lamination to secure airtightness, then sealing between components is improved, but the frame is compressed in an undesired shape, failing to secure airtightness
Solution Approach 1:
The elastomer frame is divided into a rigid support portion and a flexible sealing portion with distinct geometric configurations. The rigid support portion is designed with sufficient thickness and structural features to resist compression and maintain its shape during lamination. The flexible sealing portion is designed with appropriate flexibility to deform and conform to the sealing surfaces, ensuring airtightness. This segmentation allows controlled deformation in specific areas while maintaining overall structural integrity.
Solution Approach 2:
Different regions of the elastomer frame are assigned different mechanical properties and geometric characteristics. The rigid support portion has higher stiffness and structural rigidity to prevent undesired deformation, while the flexible sealing portion has lower stiffness and higher elasticity to accommodate compression and ensure sealing. This local quality differentiation ensures that compression during lamination occurs in controlled areas without causing overall frame deformation that would compromise airtightness.
3Strength
If conventional adhesive bonding is used to attach the frame and insert, then bonding strength is achieved, but additional adhesive members and sealing members are required, increasing material cost and manufacturing cost
Solution Approach 1:
The elastomer frame integrates multiple functions into a single component: it serves as the structural frame, the bonding layer, and the sealing element. The frame is directly bonded to the insert through thermal bonding or other bonding methods, eliminating the need for separate adhesive members and sealing members. This merging of functions reduces the total number of components, simplifies the assembly process, and reduces material costs while maintaining bonding strength and airtightness.
Solution Approach 2:
The elastomer frame is designed as a multi-functional component that simultaneously performs structural support, bonding, and sealing functions. The same elastomer material and frame structure provide both the mechanical strength needed for bonding the Membrane-Electrode Assembly and gas diffusion layer, and the flexibility needed for creating airtight seals. This multi-functionality eliminates the need for separate specialized components, reducing device complexity and manufacturing complexity.
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 stabilizes the flow of reactant gases by preventing deformation of the elastomer frame and separator, ensuring airtightness and maintaining the integrity of the gas flow paths, even during lamination, thereby enhancing the performance and reliability of the fuel cell unit.
Implementation Method 1
an elastomer frame formed in a sheet shape and bonded while being thermal bonded at the rim of the insert
Data Source
AI summary
A unit cell for a fuel cell is provided. The unit cell includes an insert including a Membrane-Electrode Assembly having a first pair of electrode layers formed on a first surface of a polymer electrolyte membrane and a second pair of electrode layers formed on a second surface of the polymer electrolyte membrane, an elastomer frame bonded at a rim of the insert in an outer area of the insert, the elastomer frame having a reaction surface through-hole in which the insert is disposed formed therein and having a plurality of frame manifold through-holes, through which a reactant gas can flow or be discharged, formed at both sides of and spaced apart from the reaction surface through-hole, and a pair of separators, each separator disposed on a respective side of the insert and the elastomer frame.