1. Effects of V substitution and annealing on Zr-based AB2 alloys as anode material of metal hydride batteries.
- Author
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Wan, ChuBin, Jiang, XiaoPing, Qi, Ying, and Ju, Xin
- Subjects
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HYDRIDES , *ANNEALING of metals , *ALLOYS , *INTERMETALLIC compounds , *ANODES , *UNIT cell , *ELECTRIC batteries - Abstract
Present paper investigates Ti 0.25 Zr 0.75 Ni 1.35-x Mn 0.65 V x (x = 0, 0.05, 0.1, and 0.15) alloys as anode active materials of metal hydride batteries. The AB 2 Laves-type alloys are prepared using arc melting and annealing. The as-cast alloys contain the major C15 and/or C14 intermetallic compounds together with the Ti–Ni and Zr–Ni secondary phases. The annealing promotes the homogeneity of the alloys and dismisses the non-Laves phases. As the V contents increase, the C15-type Laves phase transforms to the C14 structure. In addition, the unit cells of the Laves phase increase as the V contents in the alloys increase. All the studied alloy electrodes reach their maximum discharge capacities during the first 10 activation cycles. After charge/discharge 100 cycles at 300 mAg−1, the discharge capacity retentions of all the studied alloy electrodes keep more than 75%. Annealing treatment and V substitution increase the full discharge capacity from ~230 mAg−1 for N1 alloy to ~430 mAhg−1 for A4 alloy. The synthetic effects between V substitution and annealing are studied on improving the phase structure and the electrochemical properties of AB 2 -type Laves phase alloys. Image 1 • No high-cost metals were used in the studied alloys to decrease the alloy cost. • The V substitution leads to the transformation from C15 to C14 structure. • Annealing treatment increases the abundances of Laves phases. • A higher discharge capacity, 433 mA h/g of the annealed alloy with a higher V level. • V substitution and annealing play positive effects on electrochemical properties. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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