Edge-Protected Catalyst-Coated Membrane for Fuel Cell Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel cells, particularly those with catalyst-coated membranes (CCMs), exhibit reduced durability compared to catalyst-coated diffusion media (CC-DMs) due to edge-protection inefficiencies, leading to shorter lifetimes under harsh conditions.
Innovation Solution
The implementation of ionically conductive membranes with reduced-permeability layers having openings and catalyst decals, where the catalyst layers are aligned with these openings and bonded using hot pressing, with optional filling of gaps between the catalyst layers and reduced-permeability layers to reduce gas permeability and enhance adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If subgaskets are used for edge protection in CCM fuel cells, then some durability improvement is achieved, but gas cross-over and chemical degradation still occur at the edges, limiting lifetime extension
Solution Approach 1:
A reduced-permeability layer is introduced as an intermediary component between the membrane and the catalyst layer. This layer acts as a mediator that blocks gas cross-over at the edges while maintaining proton conductivity in the active region, thereby reducing harmful gas permeation without compromising the electrochemical function.
Solution Approach 2:
The reduced-permeability layer is designed with spatially varying properties: it has low gas permeability at the edges to prevent cross-over, but maintains ion conductivity in the central active area where catalysis occurs. This local differentiation of material properties allows simultaneous protection against gas leakage and preservation of electrochemical performance.
2Productivity
If the catalyst layer is extended to the edges of the membrane, then active area is maximized, but edge degradation accelerates and reduces fuel cell lifetime
Solution Approach 1:
The reduced-permeability layer creates a protective boundary zone at the edges where gas cross-over is blocked, allowing the catalyst layer to extend to the edges for maximum active area while the edge regions are simultaneously protected from degradation by the low-permeability barrier.
Solution Approach 2:
The reduced-permeability layer is positioned beforehand to protect the catalyst layer edges from gas cross-over and chemical degradation before damage can occur, enabling the catalyst to be extended to the edges without sacrificing lifetime.
3Ease of manufacture
If gaps exist between the catalyst layer and reduced-permeability layer, then manufacturing tolerance is accommodated, but gas can permeate through these gaps reducing protection effectiveness
Solution Approach 1:
The reduced-permeability layer itself acts as an intermediary barrier that spans across potential gaps between the catalyst layer and membrane, blocking gas permeation paths that would otherwise exist due to manufacturing tolerances in catalyst placement.
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 configuration significantly improves the durability of fuel cells by reducing gas cross-over and chemical degradation, extending their operational life under conditions like 95° C and 300 kPa, with edge-protected CCMs outlasting unprotected ones by several folds.
Implementation Method 1
a first reduced-permeability layer over at least one of the anode face and cathode face, and wherein the reduced-permeability layer includes an opening therethrough... wherein the first reduced-permeability layer has a permeability that is less than a permeability of the ionically conductive membrane
Implementation Method 2
a first layer having a plurality of side edges and the first layer having a central portion received in the opening in the first reduced-permeability layer, and wherein the central portion of the first layer comprises a catalyst
Implementation Method 3
an ionically conductive membrane having an anode face and a cathode face
Data Source
AI summary
A fuel cell including an anode-side catalyst coated membrane and a cathode-side catalyst coated membrane. At least a portion of a reduced-permeability layer is disposed between the ionically conductive membrane and the anode-side and cathode-side gas diffusion media, wherein the reduced-permeability layer is formed of a material that has a permeability that is less than a permeability of the ionically conductive member. The reduced-permeability layer may also be formed of a material that is softer than the ionically conductive membrane.