A Super Uniform Hydrophobic Gas Diffusion Layer for a Proton Exchange Membrane Fuel Cell

Area of Science:

• Materials Science and Engineering
• Electrochemistry
• Chemical Engineering

Background:

• Gas diffusion layers (GDLs) are critical components in proton exchange membrane fuel cells (PEMFCs).
• Conventional hydrophobic treatments, like Teflon, often result in non-uniformity, increasing resistance and hindering performance.
• Optimizing GDLs is essential for improving fuel cell efficiency and durability.

Purpose of the Study:

• To develop a uniformly hydrophobic GDL using molecular-level treatment.
• To investigate the mass transfer mechanisms within the modified GDL.
• To evaluate the impact of uniform hydrophobicity on PEMFC performance.

Main Methods:

• Liquid phase synthesis for homogeneous molecular hydrophobic GDL preparation.
• Development of a two-dimensional non-isothermal model to simulate transfer mechanisms.
• Experimental testing of fuel cells with conventional and modified GDLs.

Main Results:

• Peak power density improved by 46% with the molecular hydrophobic GDL.
• Ohmic and mass transport resistance decreased by 15% and 52% respectively at 1 A cm^-2.
• Reduced water saturation (0.13 vs 0.19) and eliminated hydrophilic dots in the modified GDL, improving gas flow.

Conclusions:

• Molecular-level uniform hydrophobic treatment is an effective strategy for GDL optimization.
• This approach significantly reduces ohmic and mass transfer resistance in PEMFCs.
• The enhanced GDL design leads to improved fuel cell performance and efficiency.