Quinary icosahedral quasicrystalline Ti-V-Ni-Mn-Cr alloy: A novel anode material for Ni-MH rechargeable batteries

摘要

The substitution of manganese and chromium for 6 at.% nickel in Ti_(1.6)V_(0.4)Ni leads the rapid quenching synthesis of quinary icosahedral phase (i-phase) evidenced by the observations of 2-, 3- and 5-fold symmetries. As negative electrode in Ni-MH battery, the quinary Ti-V-Ni-Mn-Cr i-phase can deliver a maximum discharge capacity of 278 mAh g~(-1) at 30 mA g~(-1) larger than that of Ti_(1.6)V_(0.4)Ni master alloy anode owing to Mn and/or Cr doping. After a preliminary test of 30 consecutive cycles the cycling capacity retention rate (CR%) is 80%. The strong chemisorption of hydrogen shown in cyclic voltammetric (CV) response indicates that the electrocatalytic activity improvement for the i-phase negative electrode is highly demanded.