Guided Water Percolation in 3D-Printed Gas Diffusion Layers for Polymer Electrolyte Fuel Cells

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Liquid water accumulation in gas diffusion layers (GDLs) hinders polymer electrolyte fuel cell (PEFC) performance by clogging reactant pathways.
• Optimizing GDL pore structure is crucial for efficient reactant supply and water removal in next-generation PEFCs.

Purpose of the Study:

• To investigate the potential of GDLs with tailored, deterministic pore structures for improved PEFC performance.
• To explore GDLs fabricated via carbonization of 3D-printed precursors with controlled porosity.

Main Methods:

• Operando X-ray radiography and X-ray tomography were used to track water pathways in three different GDL designs.
• Analysis focused on liquid water percolation and transport mechanisms within the engineered pore spaces.

Main Results:

• Designed GDL features effectively controlled liquid water percolation.
• A shift towards vapor phase transport of water away from the catalyst layer was observed.
• Strong convective flow was identified within the highly porous, ordered GDL structures.

Conclusions:

• 3D-printed and carbonized GDLs with deterministic pore structures offer a promising approach for advanced PEFCs.
• Engineered GDLs facilitate efficient water management, moving away from liquid water blockage.
• Optimized pore structures enhance water removal and convective transport, improving overall PEFC operation.