Effect of Ce on electrochemical properties of the TiVNi quasicrystal material as an anode for Ni/MH batteries

In order to investigate effect of Ce on electrochemical properties of the Ti1.4V0.6Ni quasicrystal, (Ti1.4V0.6Ni)99.4Ce0.6 alloy ribbon is prepared by arc melting and subsequent melt-spinning technique. The electrochemical properties of the Ti1.4V0.6Ni and (Ti1.4V0.6Ni)99.4Ce0.6 are studied as negative electrode for nickel-metal hydride batteries in aqueous KOH solution. The structures of the alloys were characterized by XRD and TEM. Phase structure investigations of the (Ti1.4V0.6Ni)99.4Ce0.6 show that alloy mainly consist of the icosahedral quasicrystal (I-phase) and face centered cubic (FCC) phase with Ti2Ni-type structure. The electrochemical measurements demonstrated that the negative electrode made by (Ti1.4V0.6Ni)99.4Ce0.6 alloy showed an improved electrochemical reversibility and a considerably higher charge-discharge capacity when compared to the Ce-free base alloy. Its maximum discharge capacity is about 300 mAh/g, which is higher than that of Ti1.4V0.6Ni, and remains 270 mAh/g after 30 cycles at a current density of 30 mA/g. The discharge process is also characterized by electrochemical impedance spectroscopy.