Bubble size distribution and electrode coverage at porous nickel electrodes in a novel 3-electrode flow-through cell. (26th January 2023)

• Record Type: Journal Article
• Authors: Rox, Hannes; Bashkatov, Aleksandr; Yang, Xuegeng; Loos, Stefan; Mutschke, Gerd; Gerbeth, Gunter; Eckert, Kerstin
• Is Part Of: International journal of hydrogen energy. Volume 48:Number 8(2023)
• Page Start: 2892
• Page End: 2905
• Publication Date: 2023-01-26
• Subjects: Bubble dynamics -- Alkaline electrolysis -- Porous electrodes -- Machine learning -- Additive manufacturing -- Membraneless electrolyzer; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2022.10.165
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: A novel 3-electrode cell type is introduced to run parametrical studies of H2 evolution in an alkaline electrolyte on porous electrodes. Electrochemical methods combined with a high-speed optical measurement system are applied simultaneously to characterize the electrodes and the bubble dynamics in terms of bubble size distribution and coverage of the working electrode. Three different cathodes made of expanded nickel are investigated at applied current densities of | j | = 10–200 mA cm −2 without forced flow and at a flow rate of 5 ml min −1 . The applied current density is found to significantly influence both the size of detached bubbles and the surface coverage of the working electrode. The forced flow through the cathodes is found to strongly reduce the bubble size up to current densities of about 100 mA cm −2, whereas the initial transient until the cathode surface is completely covered by bubbles is only marginally affected by the flow-through. Highlights: New electrochemical cell with in-situ optical inspection of electrode in two views. Simultaneous analysis of hydrogen bubble size distribution and electrode coverage. Higher current density leads to increasing bubble sizes. Applied forced electrolyte flow results in earlier bubble detachment.