Application of Ion Implantation Techniques to Anode Electrocatalyst Development for Use in Alkaline Water Electrolysis

Abstract

<p>The project is concerned with development of suitable anode electrodes for oxygen evolution in 30 w/o KOH solution at BO°C. Li ions (15 keV, 40 keV and 60 keV) at doses of 1 x 10¹⁵ to 1.5 x 10¹⁶ ions/cm², He ions (15 keV, 40 keV) at 3 x 10¹⁵ ions/cm² and Ag ion (50 keV) at 1 x 10¹⁶ to 4 x 10¹⁶ ions/cm² have been implanted into polycrystalline Ni and oxidized Ni at room temperature. Ag has also been recoil implanted into Ni and NiO. Current-potential measurements have been carried out using galvanostatic techniques with the implanted samples as the oxygen electrode in 30 w/o KOH solution at BO°C. The Ag-imp1anted electrodes show a substantial reduction in electrode potential at 1 A/cm² (~ 60% compared to polished Ni) and all implanted samples show a more uniform corrosion products on the surface. Dual Tafel slopes are observed for all electrodes and the higher slope at the higher current densities is thought to be due to the formation of nickel oxide on the electrodes. The Tafel slope and exchange current density, at low current densities are considered consistent with reported data. RBS analysis of the Ag-imp1anted electrodes indicates that no Ag is lost as a result of the electrochemical measurements.</p>