1D two-phase, non-isothermal modeling of a proton exchange membrane water electrolyzer: An optimization perspective

Abstract

Proton exchange membrane water electrolyzers (PEMWEs) have experienced a renaissance as eco-friendly devices for the storage of renewable energy surpluses. However, the scarce attention paid to green hydrogen production in the last century demands optimization to make it an affordable and reliable technology. In this work, a 1D multi-phase, non-isothermal model of a PEMWE is presented, which accounts for a complete description of mass, charge and heat transport. The predictions show good agreement with previous experimental data of single cells and stacks. The validated model is used to analyze the effect of key operating conditions, electrochemical parameters and effective transport properties on efficiency and voltage losses. The results show that the most influential variables are the temperature, the catalyst layer (CL) exchange current density (especially at the anode) and the membrane (PEM) thickness. In addition, interfacial electrical and mass transport resistances must be small and the permeability of the porous transport layers (PTLs) sufficiently high to facilitate gas–liquid counterflow in the anode. Performance can be improved through the development of CLs with good activity, thin PEMs with low permeability and stability at elevated temperatures, and permeable PTLs with tailored two-phase properties. This design perspective must be accompanied of cheaper materials.