(Invited) Understanding the Effect of Cell Assembly and Operation on AEM Electrolyzer Performance and Durability

Abstract

Water electrolysis to produce hydrogen is gaining significant attention due to a significant decrease in the cost of renewable energy sources such as solar, wind, and tidal etc. Among the existing water electrolysis technologies, anion exchange membrane water electrolysis has recently emerged due to its potential advantages over proton exchange membrane electrolysis and traditional alkaline electrolysis. Anion exchange membrane electrolyzers (AEMELs) can allow for the use of PGM-free electrocatalysts and low-cost component materials due to its less corrosive alkaline environment while also enabling electrochemical H2 compression.An overwhelming majority of the research that is going on related to AEMELs is the synthesis of advanced functional nanomaterials – e.g. new catalysts and membranes. Though these are critically important components of the cell, their function is supported by a multitude of other factors. For example, it is well-known that water and gas transport in the electrodes is highly dictated by the porous transport layers. The electrode fabrication technique controls the electrode morphology. The synthesis method for the catalyst determines its porosity and structure. The cell gasketing controls compression. The operating current density and temperature affect stress at the material and electrode level, and dictate other properties such as exchange current, ionic conductivity, water uptake, diffusivities, etc. Many of these properties are less reported and will be the subject of this presentation.This presentation will focus on understanding how various decisions that are made regarding electrode fabrication, cell assembly and cell operation affect the operating voltage and voltage stability of AEM electrolyzers. The goal of this talk is to combine electrochemical and physical characterization data to develop a series of guiding principles for AEMEL operation that can be used across polymer chemistries and catalyst selection.