Conductive Ceramic Barrier Layer for PEMFC Corrosion Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Carbon-based gas diffusion layers in electrochemical devices, such as PEMFCs, suffer from corrosion issues during high potential events like start-up/shut-down cycles and fuel starvation, leading to degradation and performance deterioration.
Innovation Solution
A barrier layer comprising electrically conductive ceramic material and a non-ionomeric polymer binder is introduced between the catalyst layer and the gas diffusion layer, providing improved resistance to carbon corrosion and stability against high cell potentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a carbon-based gas diffusion layer is used in PEMFC, then good electrical conductivity and gas transport properties are achieved, but corrosion occurs during high potential events leading to degradation
Solution Approach 1:
A barrier layer comprising electrically conductive ceramic material and non-ionomeric polymer binder is introduced between the catalyst layer and the carbon-based GDL. This intermediary layer protects the carbon material from direct exposure to high potentials and corrosive environments during start-up/shut-down cycles and fuel starvation, while maintaining electrical conductivity through the ceramic component.
Solution Approach 2:
The barrier layer is formulated as a composite material combining electrically conductive ceramic particles with a non-ionomeric polymer binder. This composite structure provides both the electrical conductivity needed for fuel cell operation and the chemical stability required to resist corrosion during high potential events, thereby protecting the underlying carbon-based GDL.
2Reliability
If a barrier layer is introduced to protect against corrosion, then carbon corrosion resistance is improved, but device complexity increases
Solution Approach 1:
The barrier layer is applied as a thin film coating on the gas diffusion layer surface. This thin film approach provides effective corrosion protection without significantly increasing the overall thickness or complexity of the MEA structure. The layer can be applied using standard coating techniques and integrated into existing manufacturing processes.
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 barrier layer significantly reduces degradation of polarization characteristics and enhances the stability of MEAs during high cell voltage operations without detrimental effects on performance, allowing for improved corrosion protection and prolonged device lifespan.
Implementation Method 1
the barrier layer comprises electrically conductive ceramic material
Implementation Method 2
improved resistance to carbon corrosion of carbon-based GDLs and leads to a better stability in start-up/shut down cycles and fuel starvation situations
Data Source
AI summary
The invention is directed to a barrier layer for corrosion protection in electrochemical devices, e.g. carbon based gas diffusion layers (GDLs) in electrochemical devices, comprising electrically conductive ceramic material and a non-ionomeric polymer binder. The electrically conductive ceramic material has an electrical conductivity of >0.1 S/cm, preferably >1 S/cm in air atmosphere (as detected by the powder method) and is selected from the group of precious metal and/or base metal containing oxides, carbides, nitrides, borides and mixtures and combinations thereof. Membrane-electrode assemblies (MEAs), catalyst-coated membranes (CCMs), gas diffusion electrodes (GDEs) and gas diffusion layers (GDLs) comprising the barrier layer of the invention show improved corrosion resistance, preferably against carbon corrosion; particularly in start-up/shut-down cycles and fuel starvation situations of PEM fuel cells.