PVDF Membrane Support Structure for Thin, Porous Fuel Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fuel cell membranes have low strength and structural integrity due to plastic elongation during production and use, which is exacerbated by the addition of conventional textile supports that increase thickness and reduce ionic transport rates.
Innovation Solution
A multi-layered textile substrate is developed for fuel cell membranes, comprising a woven layer of polyvinylidene fluoride (PVDF) fibers with a nanofiber layer deposited on top, providing enhanced porosity, chemical resistance, and structural support while maintaining thinness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional textile support structures are added to improve structural integrity, then strength is improved, but thickness increases and ionic transport rate decreases
Solution Approach 1:
The patent employs a porous PTFE membrane with controlled porosity (40-80%) and pore size (0.1-10 μm) to provide structural support while maintaining ionic transport pathways. The porous structure allows ions to pass through efficiently without requiring thick conventional textile supports, thus resolving the contradiction between strength and thickness.
Solution Approach 2:
The invention creates a composite structure combining the conductive membrane with a porous PTFE support layer. This composite approach integrates the functional requirements of the conductive membrane with the structural requirements of the PTFE support, achieving both strength and thinness simultaneously while preserving ionic transport properties.
2Strength
If conventional textile support structures are added to improve structural integrity, then strength is improved, but ionic transport rate decreases
Solution Approach 1:
The porous PTFE membrane is designed with optimized porosity (40-80%) and pore size (0.1-10 μm) to create efficient ionic transport pathways. The interconnected pore structure allows high ionic conductivity while providing mechanical strength, eliminating the trade-off between structural integrity and ionic transport rate.
Solution Approach 2:
The PTFE support layer is designed with spatially varying properties - the pore size and porosity are optimized in different regions to balance structural support requirements with ionic transport requirements. This local optimization allows the membrane to simultaneously achieve high strength and high ionic conductivity.
3Productivity
If membrane thickness is reduced to improve electron exchange, then productivity is improved, but structural integrity deteriorates
Solution Approach 1:
The porous PTFE membrane provides high structural integrity in a thin format (5-50 μm) due to its three-dimensional interconnected pore structure. This porous architecture delivers mechanical strength comparable to thicker materials while maintaining the thinness required for efficient electron exchange and ionic transport.
Solution Approach 2:
The invention transitions from conventional two-dimensional planar supports to a three-dimensional porous network structure. This dimensional change allows the thin membrane to achieve high structural integrity through vertical pore walls and interconnected frameworks, enabling both thinness and strength simultaneously.
Data Source
AI summary
A fuel cell membrane electrode assembly includes a substrate and a porous polymer membrane. The substrate includes a woven layer including a yarn of polyvinylidene fluoride (PVDF) fiber. The yarn is 7 to 25 denier. The substrate also includes a nanofiber layer including PVDF nanofibers deposited on the woven layer. The nanofiber layer is 1 to 10 micrometers (μm) thick. The substrate exhibits a porosity of at least 70 percent and is less than 30 μm thick. The porous polymer membrane is deposited on the nanofiber layer. The substrate is a porous support for a fuel cell membrane. A method of forming a fuel cell membrane electrode assembly includes weaving a woven layer of a yarn including fiber of PVDF. The method also includes depositing a nanofiber layer on the woven layer to form a substrate. The method further includes depositing a porous polymer membrane on the nanofiber layer.