Construction of Integrated Electrodes with Transport Highways for Pure‐Water‐Fed Anion Exchange Membrane Water Electrolysis

Abstract

The design of high‐performance and durable electrodes for the oxygen evolution reaction (OER) is crucial for pure‐water‐fed anion exchange membrane water electrolysis (AEMWE). In this study, an integrated electrode with vertically aligned ionomer‐incorporated nickel‐iron layered double hydroxide nanosheet arrays, used on one side of the liquid/gas diffusion layer, is fabricated for the OER. Transport highways in the fabricated integrated electrode, significantly improve the transport of liquid/gas, hydroxide ions, and electron in the anode, resulting in a high current density of 1900 mA cm–2 at 1.90 V in pure‐water‐fed AEMWE. Specifically, three‐electrode and single‐cell measurement results indicate that an anion‐exchange ionomer can increase the local OH– concentration on the integrated electrodes surface and facilitate the OER for pure‐water‐fed AEMWE. This study highlights a new approach to fabricating and understanding electrode architecture with enhanced performance and durability for pure‐water‐fed AEMWE.

Anion-exchange membrane water electrolyzers and fuel cells

“…16d, an illustration of an integrated electrode (IE) for AEMWEs proposed by Wang et al is presented, in which an ultrasonic spray of ammonia poly(N-methyl-piperidine-co-p-terphenyl) (QAPPT) ionomer into a self-supported FeNi layered double hydroxide (LDH) anode was employed. 192 Benefiting from the accelerated OH À and electron transfer kinetics, improved AEMWE performance is shown in Fig. 16e.…”

“…Apart from the catalystionomer interaction, the architecture of the anode and/or cathode layer of AEM devices also faces many challenges associated with the conventional fabrication route, such as (1) inhomogeneous catalyst ionomer distribution and low catalyst utilization; (2) inefficient electron transfer networks arising from low ionomer-catalyst adhesion; and (3) sluggish mass transfer due to the dense and thick catalyst layer, particularly for the anode layer, which has consequently inspired studies of unified and/or integrated electrodes in AEM devices. [190][191][192] As shown in Fig. 16d, an illustration of an integrated electrode (IE) for AEMWEs proposed by Wang et al is presented, in which an ultrasonic spray of ammonia poly(N-methyl-piperidine-co-p-terphenyl) (QAPPT) ionomer into a self-supported FeNi layered double hydroxide (LDH) anode was employed.…”

Anion Exchange Membrane Water Electrolyzer: Electrode Design, Lab-Scaled Testing System and Performance Evaluation

“…In principle, an ideal CL should have a hierarchical and ordered structure that a high surface area exposed nanoparticles catalysts densely loaded on the three-dimensional conductive framework and then coated with an ultrathin ionomer layer to conduct hydroxide, diffuse water, and release gas products. With the great progress of materials science in this decade, various fashion nanostructures have been constructed by advanced synthesis methods, which make the fabrication of the ordered CL structure achievable [187,191]. One group of successfully ordered electrodes was developed by the 3M company, named the nanostructured thin film (NSTF).…”

High-Performing Anion Exchange Membrane Water Electrolysis Using Self-Supported Metal Phosphide Anode Catalysts and an Ether-Free Aromatic Polyelectrolyte

“…32 A further significant problem with catalyst processing and application when it comes to both commercial water electrolyzers like AEMWE and fuel cells is that the catalysts that show good half-cell performance are mostly in the powder state and need to be immobilized onto a current collector or membrane using a suitable polymeric binder. 33,34 The traditional fabrication method of electrodes for water electrolyzers involves a catalyst ink being generally spray-coated on the membrane, which is time-consuming and puts a vast economic burden in the manufacturing process. This coating process, which is very important to maintain the catalyst stability and uniqueness, increases the interfacial resistance between the catalyst and membrane/current collector.…”