The Cycle Life of Ti0.8Zr0.2V0.5Mn0.5-xCrxNi0.8 (x=0 to 0.5) Alloys for Metal Hydride Electrodes of Ni-Metal Hydride Rechargeable Battery

Abstract

Ti-Zr-Mn-V-Ni alloys have high discharge capacities in KOH electrolyte. The rapid degradation of their capacities, however, makes them unsuitable for use as the negative electrode material in a Ni-metal hydride battery. In this work, Mn was partially substituted by Cr in the Ti-Zr-Mn-V-Ni alloys to improve their cycle lift. The microstructure, hydrogenation properties, and the cycle life of these Cr-substituted alloys were investigated. The Cr-substitution was very effective in improving the cyclic durability of alloys in spite of decreasing the discharge capacity. The surface oxidation and pulverization rate of the alloys decreased with an increasing amount of Cr. (C) 2000 The Electrochemical Society. S0013-4651 (99)05-092-2. Ail rights reserved.