Performance and Durability of Membrane Electrode Assemblies Using Ni-Based OER Catalysts for Anion Exchange Membrane Water Electrolysis

Abstract

For the large-scale commercialization of anion exchange membrane water electrolysis (AEMWE), it is essential to develop electrocatalysts that exhibit both high activity and durability. Here, we investigate the performance of membrane-electrode assemblies (MEAs) up to a current density of 4 A cm^–2, as well as durability assessments, including startup (4 A cm^–2, 10 s) and shutdown (0.1 V, 10 s) cycles and constant current density (1 A cm^–2) and load fluctuations (0–2 A cm^–2) cycles at 80 °C, of AEMWE single cells using several in-house developed Ni-based oxide catalysts (NiCoO_X, NiCoMoO_X, NiFeO_X) for the anode, and the in-house developed anion exchange ionomer (QPAF-4) for both the membrane and the catalyst layer binder. The results of the 2000-cycle accelerated degradation test demonstrate the extremely high stability of NiFeO_X, together with high MEA performance, 1.94 V@4 A cm^–2, achieved after the durability test. Based on these results, we provide strategies for the development of electrocatalysts achieving high performance and durability on the MEA level.