Effect of Ni on electrochemical and hydrogen storage properties of V-rich body-centered-cubic solid solution alloys

V-rich solid solution alloys are potential candidates for Ni-MH. negative electrodes and hydrogen sorbing materials. Mechanical alloying (MA) is used in this paper to produce Ti-0.5\V2.5-xNix,Ni. nanocrystalline alloys (x = 0, 0.1, 0.2, 0.3). A SPEX 8000 M mill is used. The aim of this work is to study the effect of chemical modification by Ni on hydrogen sorption/ desorption and electrochemical properties of V-rich body-centered-cubic (BCC) alloys. Presented measurements results show formation of BCC phase after 14 h of MA. The nanocrystallinety of obtained materials is confirmed by high resolution transmission electron microscopy images. MA alloys are tested by a Sievert's device at near room temperature. Partial substitution of V by Ni causes improved hydrogenation kinetics, reduced hysteresis and increased hydrogenation/dehydrogenation reversibility. Observed properties are mainly due to differences in structures of studied materials. Electrochemical studies on chemically modified V-rich alloys show that capacity retaining rate and discharge capacity increase with higher Ni content in the material. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.