Membrane Electrode Assembly Spray Coating for Delamination-Free Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for forming membrane electrode assemblies (MEAs) face issues such as delamination, unevenness, and limited design flexibility due to poor interfacial contact and high viscosity limitations in catalyst layer formation, leading to reduced durability and electrochemical performance.
Innovation Solution
The use of a filament extension atomizer (FEA) for spraying high polymer concentration solutions and molten polymers, allowing for the formation of catalyst layers with high catalyst and ionomer loadings, which enhances interfacial contact and design flexibility by creating atomized droplets that can be deposited on a substrate to form robust and graded ionomer/catalyst structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional hot pressing method is used to bond layers, then bonding between layers is achieved, but interfacial contact is poor leading to delamination and unevenness
Solution Approach 1:
The patent changes the physical state parameter of the ionomer solution from conventional low-viscosity to high-viscosity (40-2000 mPa·s) and applies it through FEA spray coating, enabling better interfacial contact and bonding while eliminating delamination issues associated with conventional hot pressing
Solution Approach 2:
The patent replaces the mechanical hot pressing system with a spray coating system that deposits ionomer solution directly onto catalyst layers, forming a cohesive film through solvent evaporation and polymer coalescence rather than mechanical compression, thereby achieving superior interfacial contact
2Quantity of substance
If conventional sprayers are used to spray catalyst layers, then low viscosity solutions can be applied, but high polymer concentration solutions cannot be sprayed due to strain hardening and high viscosity
Solution Approach 1:
The patent introduces a filament extension atomizer as an intermediary device between the ionomer solution and the substrate. The FEA system uses a heated capillary tube to form a molten polymer filament that is then stretched and atomized into droplets, enabling spray deposition of high-viscosity, high-concentration ionomer solutions that conventional sprayers cannot handle
Solution Approach 2:
The patent utilizes phase transition of the ionomer from solid to molten state by heating it above its melting point (e.g., 100-200°C) in the FEA system. This phase transition enables the high-concentration ionomer to be extruded as a molten filament and subsequently atomized, overcoming the viscosity limitations of conventional spray methods
3Quantity of substance
If conventional nozzles are used for spraying particles, then low particle loading can be achieved, but high catalyst loading causes clogging issues
Solution Approach 1:
The patent uses the FEA system with a heated capillary tube as an intermediary that melts and homogenizes the catalyst-ionomer mixture before atomization. This process prevents particle aggregation and clogging by ensuring uniform distribution of high catalyst loading (up to 50 wt% or more) within the molten polymer matrix, enabling continuous spray operation
4Reliability
If thicker membranes are used to prevent delamination, then bonding reliability is improved, but membrane thickness exceeds requirements and design flexibility is limited
Solution Approach 1:
The patent replaces mechanical hot pressing with direct spray coating of ionomer solution onto catalyst layers. This creates strong interfacial bonding through direct deposition and solvent evaporation, achieving reliable bonding with thin membrane thickness (e.g., 10-50 μm) and maintaining design flexibility for various MEA configurations
5Ease of manufacture
If conventional spray methods are used, then low viscosity solutions can be sprayed, but interfacial contact and bonding strength are insufficient
Solution Approach 1:
The patent changes the viscosity parameter of the ionomer solution to a high range (40-2000 mPa·s) and uses FEA spray coating to achieve both ease of manufacture and strong interfacial bonding. The heated capillary tube and filament stretching mechanism enable processing of high-viscosity materials while creating robust, delamination-free interfaces
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 approach enables improved bonding and increased contact area with the electrolyte, shortening proton transport paths and enhancing the electrochemical performance of MEAs by allowing higher catalyst and ionomer loadings, thus overcoming the limitations of conventional methods.
Implementation Method 1
a first filament extension atomizer generates an aerosol from a first catalyst layer material in fluid form, by stretching the fluid material in a nip defined between rotating rollers
Implementation Method 2
The filament extension atomizer stretches fluid filaments of the powder coating material to form droplets of powder coating material. The droplets of powder coating material are partially cooled to prevent agglomeration
Implementation Method 3
A first applying station receives the aerosol, the first applying station including outlets which deposit droplets of the aerosol on a substrate to form a first catalyst layer
Data Source
AI summary
A method and apparatus are described for forming a multilayer assembly. The method includes adhering first and second catalyst layers to opposed sides of a polymer membrane. At least one of the first catalyst layer, the second catalyst layer, and the polymer membrane is formed by filament extension atomization of a fluid material to form atomized droplets that are sprayed to form the respective membrane or layer.