A study on electrode fabrication and operation variables affecting the performance of anion exchange membrane water electrolysis

Abstract

Polymer electrolyte membrane water electrolysis has been proposed to address production of high purity hydrogen for storage of excess renewable energy. Among them, alkaline electrolyte membrane based water electrolysis (AEMWE) has an advantage in the aspect of material costs, e.g. from non-noble catalysts and membrane, but suffers from lower performance compared to proton exchange membrane based water electrolysis (PEMWE). However, there are fewer researches on single cell MEA and operation study compared to material research to enhance AEMWE performance. Here, we analyze the effect of the cell construction and operation factors, i.e MEA pressing, torque of cell assembly, electrolyte pre-feed methods, and operation temperature, to obtain high performance in AEMWE single cell operation. 97.5 % current improves at 1.8 V by applying optimized torque. 94 % decrease of ohmic resistance are achieved from electrolyte pre-feeding. 50 mA cm(-2) of current density is enhanced at 0.591 V of overvoltage per 10 degrees C temperature increase due to higher ionic conductivity and reaction kinetics. These factors significantly affect internal factors such as not only material property during operation but also, catalysts structure and contact in MEA, leading 4.3 times progress of current density from 0.242 to 1.045 A cm(-2) at 1.8 V-cell. (C) 2019 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.