Self-Supported Electrodes to Enhance Mass Transfer for High-Performance Anion Exchange Membrane Water Electrolyzer

Abstract

The rational design of electrodes is essential to achieve efficient hydrogen production via water electrolysis. This study confirms the crucial role of physical properties of electrodes in enhancing the mass transfer augmenting performance of the electrolyzer, particularly in the high-current-density region. The electrodeposition method is used to fabricate self-supported NiMo and NiFe electrodes with high wettability, porosity, and gas permeability. Then, various combinations of membrane electrode assembly with as-prepared and commercial electrodes are used to provide insight into the electrode design for mass-transfer behavior in anion exchange membrane water electrolyzer (AEMWE). The overpotentials of AEMWE with self-supported electrode pairs significantly decrease, particularly in the high-current-density region. It demonstrates a current density of 7.5 A/cm2 at a lower heating value efficiency of 50% and excellent stability at a current density of 1.00 A/cm2 for 100 h. These results emphasize the crucial role of the rational electrode design in achieving high-performance AEMWE.

Keywords: anion exchange membrane water electrolyzer, self-supported electrode, Mass Transfer, Wettability, gas permeability