Laser structured nickel-iron electrodes for oxygen evolution in alkaline water electrolysis

• Published in: International journal of hydrogen energy 2019-05, Vol.44 (25), p.12671-12684
• Main Authors: Koj, Matthias, Gimpel, Thomas, Schade, Wolfgang, Turek, Thomas
• Format: Article
• Language: English
• Subjects: Alkaline water electrolysis; Anode; Nickel-iron based catalysts; Oxygen evolution reaction; Structured mesh electrodes; Ultra-short pulse laser ablation method
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2019.01.030

In the present work, the ultra-short pulse laser ablation method is applied to create novel surface alloys on NiFe electrodes for the oxygen evolution reaction (OER) in alkaline water electrolysis. The nickel-to-iron ratio in the alloy can be controlled with the ultra-short pulse laser ablation method by varying the thickness of electrochemically deposited iron layers onto the nickel mesh substrate. Besides the application of the additional catalyst, the laser treatment enhances the surface area and a defined micro- and submicrometer structure is created in a single step. The laser structured nickel-iron electrodes show a significantly lower overpotential of 249 mV than an electrochemically deposited Ni-NiFe alloy with 292 mV at 10 mA cm−2, 298 K and 32.5 wt% KOH for the OER, although some loss of iron over time could not be prevented. •Control of NiFe alloy composition by ultra-short pulse laser ablation through variation of thickness of deposited iron layer.•Enhancement of surface area and defined micro-/ submicrometer structuring of the mesh surface in a single laser process step.•Remarkable reduction of overpotential for laser structured NiFe electrodes during OER.