Abstract: For examining the effect of the additive elements on the AB₂-type Laves phase alloys Zr_0.9Ti_0.1Ni_0.1Mn_0.7V_0.3M_0.1(M=None, Ni, Mn, V, Co, Cr, Al, Fe, Mo, Si, C, Zn, Cu and B), the phase structure, the electrochemical capacity, high rate dischargeability, charge retention, cycling stability, high-temperature and low-temperature dischargeability of the alloys have been investigated. The XRD results show that all alloys consist of a large amount of the hexagonal C₁₄Laves phase along with a small level of the cubic C₁₅Laves phase and some non-Laves phases. The addition of Vand Mn increases the discharge capacity of the AB₂alloy electrodes and the high rate capacity, and low-temperature dischargeability is dramatically increased with Band Mn addition, the Zr_0.9Ti_0.1Ni_1.1Mn_0.7V_0.3B_0.1exhibited the discharge capacity of 200mAh/g at discharge current of 1320mA/g. It is found that a small amount ddition of Al, C, Si and Co greatly improved the cycle life, but addition of Mn, V, Ni, Fe, Cu, Mo and Bdecreased the cycling stability of the AB₂alloy electrodes to some extent, especially addition of Mn resulted in decreasing of cycling stability drastically. The addition of Si, Mo, V, Cr and ALIs useful to improving self-discharge characteristics. Considerable improvement in the high-temperature dischargeability was observed by addition of Si, Cr and V, the discharge capacity was up to 210 mAh/g at 65 ℃ for Zr_0.9Ti_0.1Ni_1.1Mn_0.7V_0.3Si_0.1alloy electrode.

Key words: Laves phase alloy, Addition of elements, Electrochemical properties, Hydrogen storage alloy