Ti1.4V0.6Ni quasicrystal and its composites with xV(18)Ti(15)Zr(18)Ni(29)Cr(5)Co(7)Mn 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 30 mA g(-1) at 303 K. Also, composite materials lead to significant improvement in the high-rate dischargeability (HRD) as well as the cyclic stability. (C) 2012 Elsevier B.V. All rights reserved