Designing a Maze-Structured Gas Diffusion Layer to Extend Water Transport Path for Enhancing the Performance and...

Area of Science:

• Energy Conversion and Storage
• Materials Science
• Electrochemistry

Background:

• Air-cooled fuel cells face performance degradation due to low internal humidity.
• Rapid water expulsion from the gas diffusion layer (GDL) in air-cooled fuel cells reduces membrane electrode assembly (MEA) hydration.
• Low humidity impairs proton exchange membrane (PEM) conductivity, affecting fuel cell performance and durability.

Purpose of the Study:

• To design and evaluate a novel maze-like gas diffusion layer (M-GDL) for air-cooled fuel cells.
• To enhance internal humidity and mitigate performance loss caused by water expulsion.
• To improve the overall efficiency and longevity of air-cooled fuel cell systems.

Main Methods:

• Design of a GDL with a maze-like structure inspired by tortuous transport pathways.
• Implementation of a water evaporation test to quantify water loss resistance.
• Performance testing of fuel cells utilizing the M-GDL compared to commercial GDL.

Main Results:

• The M-GDL demonstrated significantly lower water loss rates (0.35 mg min⁻¹ cm⁻²) compared to commercial GDL (0.79 mg min⁻¹ cm⁻²).
• Fuel cells equipped with M-GDL achieved a peak power density of 0.77 W cm⁻², more than double that of commercial GDL (0.4 W cm⁻²).
• The maze structure effectively extended water transport pathways, increasing internal humidity.

Conclusions:

• The developed M-GDL is an effective strategy to improve water retention in air-cooled fuel cells.
• Enhanced internal humidity directly translates to improved fuel cell performance and power density.
• This research offers a promising approach for advancing air-cooled fuel cell technology.