Modification of a rapidly solidified hydrogen storage electrode alloy by ball-milling with Co3Mo

Rapidly solidified hydrogen storage alloys were reported to have good cycle life, but they are very difficult to activate, especially for AB(2) type a lloys. In this study, a Zr0.9Ti0.1 (Ni0.57V0.1Mn0.28Co0.05)(2.1) alloy was prepared by melt-spinning followed by ball-milling with Co3Mo additive in o rder to improve its kinetic characteristics. The experimental results showe d that the alloy exhibited a much improved activation performance as well a s electrochemical capacity after 2 hours milling. Cyclic voltammetry and el ectrochemical impedance experiments also showed that ball-milling of the al loy with Co3Mo could improve the surface activation property to a great ext ent. This can be attributed to the catalytic effect of Co3Mo, which had a m uch closer contact to the alloy powders after ball-milling, on the hydrogen oxidation. However, long time milling could decrease the capacity graduall y due to the further amorphization of the ahoy. (C) 1999 Published by Elsev ier Science S.A, All rights reserved.