Enhancing Mass Transport Efficiency in High-Current Density PEMECs by Constructing Ti-Fiber Oriented Porous Transport...

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Proton exchange membrane electrolysis cells (PEMECs) are crucial for hydrogen production.
• Anode porous transport layers (PTLs) significantly impact PEMEC efficiency by managing gas/liquid two-phase flow.
• Optimizing PTLs is essential for enhancing performance, particularly at high current densities.

Purpose of the Study:

• To design and fabricate novel titanium fiber PTLs using an angle-selective stacking method.
• To investigate the effect of fiber orientation on PTL performance in PEMECs.
• To improve mass transfer and reduce resistances in PEMECs.

Main Methods:

• Fabrication of titanium fiber PTLs with stacking angles of 30°, 60°, and 90°.
• Characterization using X-ray micro-computed tomography.
• Electrochemical testing and computational fluid dynamics (CFD) simulations.

Main Results:

• Oriented PTLs effectively avoid dead zones within the porous structure.
• The 30° oriented PTL significantly enhanced oxygen expulsion and reduced mass transport resistances.
• Compared to commercial titanium felt, the 30° PTL reduced polarization voltage by ≈67 mV and mass transport resistance by 16 mΩ cm⁻² at 3 A cm⁻².

Conclusions:

• Angle-selective stacking of titanium fibers offers a new strategy for PTL design.
• Optimized fiber arrangement in PTLs can substantially improve PEMEC efficiency.
• This approach provides a pathway for enhanced mass transport in electrochemical devices.