Key components and design strategy of the membrane electrode assembly for alkaline water electrolysis

Abstract

Alkaline water electrolysis for hydrogen production is a promising approach to address the severe energy crisis. Membrane electrode assemblies (MEAs) provide an important place for the electrochemical reaction and multiphase...

Opportunities of Ionomer Development for Anion-Exchange Membrane Water Electrolysis

“…While crucial for DI water operation, a collation of the literature in a recent review by Wang and co-workers does not yet show a distinct trend between electrode fabrication techniques and performance nor stability of electrodes operating in 1 M KOH. 41 It is currently unknown which CL architecture will dominate future AEM-WE systems, however, in order to ensure sufficient stability in the short term, commercial AEM-WEs may initially favor the use of ionomer-free electrodes, with dilute supporting electrolytes. 44 As ohmic resistances will likely need to be decreased, research challenges focusing on reducing the ionic resistances of the CL and reducing kinetic overpotentials through optimizing catalyst utilization will likely continue to expand.…”

“…Concurrent with the increase in membrane stability in alkaline media, there has also been a significant increase in membrane conductivity, enabling the commercialization of a wide variety of AEMs such as Fumasep FAA-3 (Fumatech), A201 (Tokuyama), Aemion (Ionomr Innovations), Sustainion (Dioxide Materials), Orion TM1 (Orion Polymer), and PiperION (Versogen). , Advances in membrane technology have also been supported by the increasing development of non-noble metal HER − and OER catalysts, − culminating in the rapid advancement of anion-exchange membrane water electrolysis (AEM-WE), for which excellent reviews are available. ,− The beginning of life performance (BOL) of AEM-WE systems is comparable to that of PEM-WE but at a fraction of the cost of materials. It is estimated that the investment cost for a 1 MW AEM-WE stack is 42% lower than that of a PEM-WE (Figure c)…”

“…Layered-double hydroxides (LDHs) where molecular layers of positively charged MO 6 octahedra are intercalated with anionic species have also received considerable attention and promise as OER catalysts, especially when fabricated directly on Ni substrates. , The ability to control the structure of catalysts by growth on top of metallic substrates has led to high performance electrode architectures . For example, Wan, Wang et al fabricated self-supported electrodes of vertically aligned NiFe-LDH nanosheets directly formed on Ni foam .…”

“…It is clear that the need for the ionomer depends on the desired morphology and architecture of the CL as well as design choices of the electrolyzer. While crucial for DI water operation, a collation of the literature in a recent review by Wang and co-workers does not yet show a distinct trend between electrode fabrication techniques and performance nor stability of electrodes operating in 1 M KOH . It is currently unknown which CL architecture will dominate future AEM-WE systems, however, in order to ensure sufficient stability in the short term, commercial AEM-WEs may initially favor the use of ionomer-free electrodes, with dilute supporting electrolytes .…”

Application of Ionized Intrinsic Microporous Poly(phenyl-alkane)s as Alkaline Ionomers for Anion Exchange Membrane Water Electrolyzers

“…8 The membrane electrode assembly (MEA) is the basic unit of an AEMWE and is mainly composed of an anion exchange membrane (AEM), a catalyst layer (CL), and a gas diffusion layer (GDL). 3,9 The structural design and components of MEAs directly determine the H 2 output rate and cell efficiency of AEMWEs. Therefore, developing improved MEAs is crucial for the advancement of AEMWEs.…”