The cobalt alkylene polyamine complex, known as a kind of cobalt complexes, is mixed with VB and VIB compounds (in the Periodic Table VB and VIB) such as vanadium pent oxide, sodium molybdate etc. according to a certain proportion. Then it is added to alkaline electrolyte. In the process of water electrolysis, metal ions in lower overvoltage are introduced into the cathode chamber of the electrolytic cell and are plated onto the nickel based electrode, which increases the activity of cathodic electrolysis, thereby reducing the electrolysis power consumption of cell voltage. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.