Ti1.4V0.6Ni quasicrystal and its composites with xV18Ti15Zr18Ni29Cr5Co7Mn alloy used as negative electrode materials for the nickel–metal hydride (Ni–MH) secondary batteries

Abstract

This study examined the structure and electrochemical hydrogen storage characteristics of the Ti1.4V0.6Ni quasicrystal and their ball-milled composites with V18Ti15Zr18Ni29Cr5Co7 alloy. It is found by XRD that composite material alloys consist of the icosahedral quasicrystal (I-phase), C14 Laves phase with a hexagonal structure and a V-based solid solution phase with a BCC structure and a face centered cubic (FCC) phase with a Ti2Ni-type structure. The maximum discharge capacity of the alloy electrodes increases with increasing V18Ti15Zr18Ni29Cr5Co7 in the Ti1.4V0.6Ni alloy when using such composite materials as Ni–MH battery anodes under the condition that the discharge current density is 30mAg−1 at 303K. Also, composite materials lead to significant improvement in the high-rate dischargeability (HRD) as well as the cyclic stability.