Mathematical modeling of novel porous transport layer architectures for proton exchange membrane electrolysis cells. (21st July 2021)

• Record Type: Journal Article
• Authors: Wrubel, Jacob A.; Kang, Zhenye; Witteman, Liam; Zhang, Feng-Yuan; Ma, Zhiwen; Bender, Guido
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 50(2021)
• Page Start: 25341
• Page End: 25354
• Publication Date: 2021-07-21
• Subjects: Water electrolysis -- Hydrogen -- Proton exchange membrane electrolysis cell -- Electrochemical modeling -- Multiphase transport -- Porous transport layer; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.05.070
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Thin foil based porous transport layers (PTLs) that contain highly structured pore arrays have shown promise as anode PTLs in proton exchange membrane electrolysis cells. These novel PTLs, fabricated with advanced manufacturing techniques, produce thin, tunable, multifunctional layers with reduced flow and interfacial resistances and high thermal and electric conductivities. To further optimize their design, it is important to understand their fundamental impact on the transport of protons, electrons, and liquid/vapor mixtures in the electrode. In this work, we develop a two-dimensional multiphysics model to simulate the coupled electrochemistry and multiphase transport in an electrolysis cell operated with the novel PTL architecture. The results show that larger pores improve access of water to the anode catalyst layer, which is beneficial for both the oxygen evolution reaction and membrane hydration. Larger pore sizes also improve oxygen gas transport from the catalyst layer, because generated oxygen gas is forced to travel in-plane through the anode catalyst layer until it reaches a pore opening that is connected to a channel. The discussed results confirm that the proposed thin foil based PTLs are fundamentally different from conventional PTLs, such as felts or layered meshes. The model developed in this work also provides generalizable insight into fundamental PEMEC phenomena, such as the competition between liquid and gas phase transport, membrane hydration and water management, and nonuniform electrochemical reactions, which are processes relevant to all PEMEC designs. Highlights: Present a state-of-the-art modeling tool for PEMECs. Electrochemical transport model to simulate multiphase transport. Spatial resolution of electrochemical reactions and membrane hydration. Fundamental insight to coupled transport phenomena during operation.