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Intensification of Alkaline Electrolyzer with Improved Two‑Phase Flow
Author(s) -
Egert Franz,
Ullmer Dirk,
Marx Sven,
Taghizadeh Ehsan,
Morawietz Tobias,
Gerle Martina,
Le Thi Anh,
Campo Schneider Lucia Paula,
Biswas Indro Shubir,
Wirz Richard E.,
Spieth Philipp,
MarquardMöllenstedt Tonja,
Brinner Andreas,
Faccio Ricardo,
FernándezWerner Luciana,
Esteves Martín,
Razmjooei Fatemeh,
Ansar Syed Asif
Publication year - 2025
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202405285
Subject(s) - materials science , tortuosity , electrolysis , electrode , ohmic contact , current density , electrolyte , current (fluid) , porosity , alkaline water electrolysis , chemical engineering , hydrogen , nickel , hydrogen production , composite material , metallurgy , thermodynamics , chemistry , organic chemistry , engineering , physics , layer (electronics) , quantum mechanics
Abstract Green hydrogen produced through water electrolysis offers a promising pathway to global decarbonization. Among various electrolyzers, alkaline water electrolysis (AWE) is the most established and commercially mature. To reduce the cost of hydrogen production from AWE, it is crucial to increase operational current density while maintaining or lowering voltage to increase hydrogen yield and reduce energy consumption. Such efforts are focused on reducing the ohmic resistance at high current densities through the implementation of alkaline membranes. However, this work underlines that the ohmic resistance at high current densities is also influenced by the losses associated with the evolution of bubbles at the electrode surface and two‐phase mass transfer. This is shown by investigating the impact of tortuosity and bubble point of porous electrodes on AWE performance. Low‐tortuosity porous nickel electrodes are fabricated and analyzed for their ability to reduce capillary pressure and bubble point, resulting in lower energy losses and improved efficiency. The cell reaches an industrially appealing relevant current density of 2 A cm −2 at ≈2 V. Besides test in single cells, the advantageous effect of these low tortuosity porous nickel electrodes are also validated in a kW‐class AWE stack, confirming their effectiveness in enhancing overall system performance.