Pathways towards Achieving High Current Density Water Electrolysis: from Material Perspective to System Configuration

Abstract

Hydrogen is a clean, flexible, powerful energy vector that can be leveraged as a promising alternative to fossil fuels. Additionally, green hydrogen production has been recognized as one of the most prevalent solutions to decarbonize the energy system. Water electrolysis studies have increased throughout the decade as higher industrial interest comes into play. The catalyst, system design, and configuration act in a congenial manner to deliver high‐performing water electrolysis. Despite performance targets peaking at high current densities, the current status of water electrolyzer technologies would require more research efforts to achieve such goals. This work presents a comprehensive review of how catalysts and electrolyzer designs can be enhanced to attain high current density water electrolysis. Modification strategies of catalysts, advances in characterization and modelling, and optimizing system designs are highlighted. Furthermore, this paper aims to elucidate the future research direction of water electrolysis to bridge the laboratory‐to‐industry gap.

How advances in theoretical chemistry meet industrial expectations in electrocatalysts for water splitting

“…, Zirfon©) is used to separate the half cells to prevent gas crossover. 55–57 The diaphragm is permeable to the liquid electrolyte, thus the hydroxide ions produced at the cathode during proton reduction can diffuse to the anode. Lower (compared with proton exchange membrane electrolysers, PEM_EL) current densities (up to 0.5–1.0 A cm −2 , depending on the catalyst used and influenced by the higher resistance of the cell assembly), and a corrosive electrolyte are the main drawbacks.…”

Industrially Relevant Conditions in Lab‐Scale Analysis for Alkaline Water Electrolysis

“…This is not only caused by the use of thick diaphragms but also by a lack of efficient electrocatalysts, especially to improve the sluggish oxygen evolution reaction (OER) [5] . Therefore, in the past decades, countless noble metal‐free catalyst materials have been developed and investigated [6] . In fact, some materials even outperformed state‐of‐the‐art catalysts in terms of OER activity under laboratory conditions [7–10] .…”

A Guide to Electrocatalyst Stability Using Lab-Scale Alkaline Water Electrolyzers

“…18 Understanding electrocatalyst integration into flow cells and their response to industrially relevant conditions is crucial for advancing commercially viable technologies. 2,12 A substantial challenge in AWE research is the lack of standardized protocols. Unlike PEM electrolysis and fuel cell research, 10,11,21−23 the AWE community still lacks standardized procedures for cell configurations, device assembly, accelerated stress tests, reference materials, and reporting data.…”

“…Hydrogen is expected to play a critical role in the electrification and decarbonization of industrial and commercial sectors, becoming increasingly cost-competitive with large-scale fossil fuels. − Green hydrogen from low-temperature water electrolysis has received significant attention with a projected thousand-fold global capacity expansion by 2030 . This technology branches into three configurations: proton exchange membrane (PEM) electrolysis, alkaline water electrolysis (AWE), and anion exchange membrane (AEM) electrolysis .…”

“…Beyond only reporting the catalytic activity, there is an urgent need in the AWE field to understand practical issues, including catalyst deactivation, gas crossover, and bubble removal. , These aspects are critical under high current density conditions, as the operating environment is drastically different from laboratory configurations where local pH changes, corrosion, and mass transfer are typically neglected . Understanding electrocatalyst integration into flow cells and their response to industrially relevant conditions is crucial for advancing commercially viable technologies. , …”