Water Transport Modeling in a Microporous Layer for a Polymer Electrolyte Membrane Water Electrolyzer Having a Gas-Liquid Separating Interdigitated Flow Field

Abstract

A new interdigitated flow field design for polymer electrolyte membrane electrolyzers has been developed for ground and space applications. It internally separates oxygen and liquid water, eliminating the water circulators to remove the bubbles and external gas-liquid separators with buoyancy. The capillary pressure in the hydrophobic microporous layer(MPL) of the anode porous transport layer enables the internal separation of oxygen gas and pressurized liquid water. A finite element model (COM-SOL Multiphysics) simulates water transport in the MPL. Electrochemical impedance spectra determine the electrochemical kinetic parameters for the model. The model accounts for the oxygen bubble coverage of the CL, liquid water saturation in the MPL, and the current ratio between liquid water and water vapor at the MPL-CL interface. The vapor from liquid water in the MPL mixes with oxygen for diffusion. The water evaporation rate based on liquid water saturation in the MPL is introduced.

Numerical Modeling and Topology Optimization for Designing the Anode Catalyst Layer in Proton Exchange Membrane Water Electrolyzers Considering Mass Transport Limitation

“…The validation of the performance curve revealed consistent alignment with experimental data, effectively capturing moderate mass transfer limitations. Not only that, but such a two-phase flow numerical model was also applied in diverse applications, including developing a new flow field design 20 and conducting parametric studies. 21,22 Nevertheless, both experimental and numerical studies have often relied on intuition-based designs, which can be costly and may not necessarily yield the optimal solution.…”