UC Irvine

Renewable and sustainable hydrogen production is necessary for facilitating the decarbonization of several industries including ammonia production, maritime shipping, heavy duty vehicle transport, and cement and steel production. Hydrogen can be renewably produced via water electrolysis. Proton exchange membrane water electrolyzers (PEMWEs) are expected to makeup 40% of the electrolyzer market by 2050. Currently, widespread deployment is limited by capital costs of stacks. A portion of these costs are due to the highly oxidative environment at the anode necessitating the use of titanium for the flow-field and porous transport layers (PTLs). Alternative flow-field and PTLs designs can reduce titanium usage through reductions in component thickness and enabling the use of alternative materials such as stainless steel.Rapidly exploring different designs for flow-fields and PTLs and evaluating their electrochemical performance can be costly. Additionally, the impact of those designs on transport phenomena within the cell is difficult to resolve experimentally. Multi-scale and multiphysics models can resolve such transport phenomena and aid in efficiently evaluating alternative flow-field and PTL architectures. This work aims to develop modeling tools and design frameworks for evaluating expanded metal mesh (EMM) flow-fields and straight-through pore (SP) PTLs, and to investigate stainless steel PTLs.The first part of this dissertation focuses on an alternative anode architecture comprised of an EMM pack and SP-PTL. The heat removal and pressure loss as a function of different geometric parameters in EMM flow-fields are evaluated using a single-phase computational fluid dynamics (CFD) model. The electrochemical performance and temperature distributions in EMMs are then investigated using a 2D multi-physics PEMWE model. This design framework is then applied to straight-through pore PTLs. The 3D CFD model is used to evaluate the permeability of SP-PTLs at different pore diameters, open areas, and layer configurations. The 2D multi-physics model is then adapted to include the SP-PTL with the EMM flow field to investigate the cell performance at different catalyst loadings and geometric configurations. A finite element analysis (FEA) is then conducted to assess mechanical stability of SP-PTLs and EMMs. The results from these simulations are used to identify the geometric parameters in SP-PTLs that are critical for maximizing cell performance, heat removal, and mechanical stability while minimizing pressure loss.The latter part of this work focuses on enabling the use of stainless steel PTLs. The electrochemical performance and corrosion resistance of industrially provided Ti-coated stainless steel PTLs were evaluated experimentally. X-ray computed tomography is then used to investigate the morphology of each sample. Additionally, the previously developed 2D multi-physics model is then extended to explore the ionic potential distribution in the anode and identify an optimal Ti-coating thickness for minimizing corrosion.