Gas Diffusion Layer Flowpath Design for Fuel Cell Gas Supply
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Solution Overview
Problem
Conventional fuel cells with embedded electroconductive wires in the catalyst layer face insufficient gas supply, leading to reduced power generation capability due to electrical resistance and limited gas diffusion.
Innovation Solution
A gas diffusion layer with a flowpath is created by disposing electroconductive wires of specific diameter on an electroconductive substrate, forming a low-height gas flow channel that allows for adjustable gas supply and efficient water removal, enabling superior power generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electroconductive wires are embedded within the catalyst layer to reduce electrical resistance, then electrical conductivity is improved, but gas supply to the catalyst layer becomes insufficient
Solution Approach 1:
The gas diffusion layer is segmented into multiple functional regions: a base layer for gas diffusion and a separate flow channel structure for fluid transport. This segmentation allows the flow channels to be positioned optimally for gas supply without interfering with catalyst layer integrity, resolving the conflict between electrical conductivity and gas supply.
Solution Approach 2:
The invention transitions from two-dimensional embedding of wires within the catalyst layer to a three-dimensional structure where flow channels are formed above the catalyst layer. This dimensional change allows gas to be supplied directly to the catalyst layer surface while electroconductive wires maintain electrical contact, simultaneously achieving both electrical conductivity and sufficient gas supply.
2Volume of moving object
If flow channel height is reduced to minimize fuel cell size, then device compactness is improved, but gas diffusion efficiency deteriorates
Solution Approach 1:
The gas diffusion layer exhibits local quality variations with different regions having distinct properties: the base layer provides porous structure for diffusion, while the flow channel regions provide directed gas flow paths. This local differentiation enables efficient gas distribution throughout the catalyst layer even with reduced overall flow channel height.
Solution Approach 2:
The gas diffusion layer utilizes porous materials with optimized pore size distribution and connectivity. The porous structure facilitates efficient gas diffusion through the layer thickness while the flow channels provide macro-scale gas distribution, maintaining high gas diffusion efficiency in a compact configuration.
3Quantity of substance
If electroconductive wires are disposed on the electroconductive substrate to form flow channels, then gas supply is improved, but device complexity increases
Solution Approach 1:
The electroconductive wires serve multiple functions simultaneously: they provide electrical conductivity for current collection and form the structural framework for flow channels. This multi-functionality reduces the need for separate components, simplifying the overall device structure while achieving improved gas supply.
Solution Approach 2:
The invention merges the electrical conductivity function and flow channel structure into a single integrated component. The electroconductive wires are disposed on the electroconductive substrate to create both electrical pathways and gas flow channels, combining two essential functions into one element and reducing device 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
The solution reduces the size of fuel cells, enhances gas diffusion, and improves power generation efficiency by minimizing electrical resistance and pressure loss, while maintaining sufficient gas supply and electrical conductivity.
Implementation Method 1
The GDL requires a gas supply mechanism for efficiently diffusing and supplying the fuel gas and oxidant gas to the catalyst layers
Implementation Method 2
a fuel gas (such as hydrogen gas) is supplied to the anode side of the individual cell, and an oxidant gas (such as air or oxygen) is supplied to the cathode side. This results in the electrochemical reactions represented by the following formulas occurring at the anode and the cathode, thereby generating power
Data Source
Figure 1(a)~1(b)
Figure 2~3
Figure 4~5
AI summary
[Problem] To provide a thin gas diffusion layer with flowpath while ensuring superior gas diffusion. [Solution] A gas diffusion layer with flowpath in which electroconductive wires A for forming flow channels are disposed upon an electroconductive substrate B, the flow channels formed by the electroconductive wires A having a height of 300 µm or less, and flow channels formed by adjacent electroconductive wires A having an equivalent diameter of 300 µm or less.