Preparation and electrochemical hydrogen storage property of alloy CoSi

A series of hydrogen storage alloys CoSi were prepared by means of ball milling at different hours and investigated as anode materials in aqueous KOH solution. The structures of the alloys were characterized by XRD, SEM, and TEM. The electrochemical experimental results demonstrated that the CoSi particles so prepared showed excellent electrochemical reversibility and considerably high charge-discharge capacity. CoSi milled 10 h had the highest initial discharge capacity of 400 mAh/g at current density 25 mA/g, while the CoSi milled 40 h showed excellent cycling stability as there were no declination after 80 charge-discharge cycles and the capacity kept about 230 mAh/g. The hydrogen storage mechanism was studied by XRD and XPS. (c) 2006 Elsevier B.V. All rights reserved.