Local Hydrophilic Gas Diffusion Layer for Fuel Cell Water Management
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Solution Overview
Problem
Existing gas diffusion layers in fuel cell stacks face challenges in effectively managing water removal due to their hydrophobic properties, which hinder efficient drainage of produced water, especially in serpentine channel systems where water accumulation varies with current, temperature, and gas moisture content.
Innovation Solution
A local hydrophilic gas diffusion layer is designed with distinct regions under clamping pressure lands and gas channels, where the first region undergoes hydrophilic treatment and pore size reduction, enhancing capillary water discharge through the capillary effect, while the second region remains hydrophobic, optimizing water removal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gas diffusion layer is made hydrophobic, then water accumulation is reduced, but water removal efficiency deteriorates
Solution Approach 1:
The gas diffusion layer is divided into two distinct regions: a first region with hydrophobic properties to prevent water accumulation and a second region with hydrophilic properties to efficiently remove water. This local differentiation of surface properties allows each region to perform its specific function optimally, resolving the contradiction between preventing water accumulation and removing water efficiently.
2Productivity
If plasma treatment is used to enhance water removal, then water removal efficiency improves, but manufacturing complexity and cost increase
Solution Approach 1:
Instead of using complex plasma treatment processes, the invention creates a local quality difference by forming a specific pore structure pattern during the manufacturing process itself. The first region has a closed-cell structure that is hydrophobic, while the second region has an open-cell structure that is hydrophilic. This approach achieves the desired water removal efficiency through structural design rather than complex surface treatment processes.
3Productivity
If the gas diffusion layer is made entirely hydrophilic, then water removal efficiency improves, but water accumulation control deteriorates
Solution Approach 1:
The gas diffusion layer employs local quality differentiation with a hydrophobic first region to control water accumulation and a hydrophilic second region to enhance water removal efficiency. This spatial separation of functional properties allows the system to simultaneously achieve both water accumulation control and efficient water removal, rather than requiring the entire layer to be uniformly hydrophilic or hydrophobic.
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 water removal efficiency by forming a liquid film flow along the gas channel walls, enhancing the fuel cell stack's performance without requiring complex processes like plasma treatment, thus simplifying manufacturing and reducing costs.
Implementation Method 1
the first region undergoes hydrophilic treatment and pore size reduction, enhancing capillary water discharge through the capillary effect
Data Source
AI summary
The present invention provides a local hydrophilic gas diffusion layer configured to enhance the water removal performance of a fuel cell For this purpose, the present invention provides a gas diffusion layer in which a region under each of a pair of lands, which receives a clamping pressure of the fuel cell stack, is subjected to local hydrophilic treatment by a simple process, thereby enhancing the water removal performance of the fuel cell stack. In particular, the local hydrophilic gas diffusion layer has a first region under each land of the separator which receives the clamping pressure; and a second region under the gas channel of the separator, wherein the first region is subjected to hydrophilic treatment.