Zinc treatment to enhance nickel electrode performance for liquid alkaline water electrolyzers

Raney Ni treatment is introduced to the surface of Ni mesh anode electrodes, enhancing liquid alkaline water electrolyzer performance. The surface of the Ni mesh is alloyed with Zn, deposited by either an aqueous infiltration of Zn salt or direct reaction with Zn foil. The extent of alloying is controlled by a heat treatment step. For both processes, fine porosity and enhanced surface area are obtained after leaching the Zn out of the surface alloy layer. The observed electrode surface structure and performance is quite sensitive to the thermal treatment temperature. The enhanced surface area improves full cell performance by 90 mV for infiltrated Zn treated at 600 °C and by 185 mV for Zn foil reacted at 425 °C (at 2 A cm⁻² and 80 °C). The Zn treatment methods produce stable operating performance, exhibiting no decay after 150 h for the infiltrated Zn treated at 600 °C, and a decay rate of 4.6 μV h⁻¹ over 100 h for the Zn foil reacted at 425 °C (at 1 A cm⁻² and 80 °C).