EFFECT OF ADDING CHROMIUM TO TI-ZR-NI-V-MN ALLOY ON ITS CYCLE LIFE ASAN 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 batterie s made from these alloys. It is found that the addition of chromium si gnificantly reduces the discharge capacity although it has only a limi ted effect on the hydrogen absorption/desorption performance. Presumab ly, chromium has a negative effect on the discharge kinetics. In addit ion, chromium controls the dissolution of V and Zr and hence, extends cycle life. An optimal material, Ti0.35Zr0.65Ni1.2V0.6Mn0.2Cr0.2 is id entified and prepared. This possesses acceptable performance with resp ect to both discharge capacity and cycle life.