Design of highly active, bifunctional Raney-Nickel electrodes for alkaline water electrolysis (AWE) at high currents via Sn-doping

In this work, electronically and structurally modified Raney-Nickel electrodes for bifunctional use as anode and cathode for alkaline water electrolysis (AEL) are presented. Via Sn-doping theNi-based electrodes are modified to improve surface and kinetics during oxygen and hydrogen evolution (OER/HER) significantly. The fabricated electrodes are competitive with state-of-the-art PGM electrodes due to their low overpotentials of 220-350 mV up to >1 A/cm 2 with cell potentials of < 1.7 V. Electrochemical active surface areas of up to 4980 cm 2 /cm 2 geo are reached. A very low long-term degradation rate (>500 h) is measured with <4 μV/h in accelerated stress tests (AST). The electrodes are prepared using a simple cost-reducing process. A spray coating of a nickel-aluminum dispersion with an Al:Ni composition of 3:1 to 9:1 and doping with 1-2% Sn on a nickel mesh is followed by a thermal treatment step.