Effect of adding chromium to Ti-Zr-Ni-V-Mn alloy on its cycle life as an Ni/metal-hydride battery material

Chromium is added to Ti-Zr-Ni-V-based AB(2)-type alloys to investigate its effect on the cycle-life performance of Ni/metal-hydride batteries made from these alloys. It is found that the addition of chromium significantly reduces the discharge capacity although it has only a limited effect on the hydrogen absorption/desorption performance. Presumably, chromium has a negative effect on the discharge kinetics. In addition, chromium controls the dissolution of V and Zr and hence, extends cycle life. An optimal material, Ti0.35Zr0.65Ni1.2V0.6Mn0.2Cr0.2 is identified and prepared. This possesses acceptable performance with respect to both discharge capacity and cycle life.