AB5-type alloys are commercially used in electrodes for rechargeable batteries due to their high capacity, good kinetics for the hydriding/dehydriding reactions and long useful life (cycling resistance). The aim of this work is to study, using electrochemical impedance spectroscopy, the influence of the preparation compaction pressure, on the performance of the electrode. The results show the effect of increasing compaction pressure on the interfacial and active areas, and on the reduction of the contact resistance between particles. In this study a pressure range for optimal electrode behavior is determined. These results agree with behavior predicted by the proposed physicochemical model and with experimental results reported in previous works, using others electrochemical techniques. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.