X.B. Yu

A Ti-V-based bcc phase alloy for use as metal hydride electrode with high discharge capacity.

The electrochemical characteristics of single bcc phase Ti-30V-15Cr-15Mn alloy were investigated. It was demonstrated that the single bcc phase alloy has high electrochemical discharge performance at high temperature. Its discharge capacity is closely related with temperature and discharge current. The first discharge capacities of 580-814 mAh g(-1) of the alloy powder were obtained at discharge current of 45-10 mA g(-1) in 6 M KOH solution at 353 K. Although the electrochemical cycle life of the alloy is unsatisfactory at present, it opens up prospects for developing a new hydrogen storage alloy with high hydrogen capacity for use as high performance metal hydride electrodes in rechargeable Ni-MH battery.

Electrochemical performance of Ti0.4V0.3Mn0.15Cr0.15 alloy surface-modified by ballmilling with LaNi3.55Co0.75Mn0.4Al0.3

The characteristics and mechanisms of enhanced electrochemical properties of Ti 0.4 V 0.3 Mn 0.15 Cr 0.15 + x wt % LaNi 3.55 Co 0.75 Mn 0.4 Al 0.3 composite alloys produced by ballmilling were investigated. Surface modification of Ti 0.4 V 0.3 Mn 0.15 Cr 0.15 alloy by ballmilling with LaNi 3.55 Co 0.75 Mn 0.4 Al 0.3 can significantly improve its electrochemical properties. After 30 min of ballmilling, the discharge capacity increases from 205 mAh g -1 for the plain Ti 0.4 V 0.3 Mn 0.15 Cr 0.15 alloy to 420 mAh g -1 for the Ti 0.4 V 0.3 Mn 0.15 Cr 0.15 + 50 wt % LaNi 3.55 Co 0.75 Mn 0.4 Al 0.3 composite alloy. The improvement of cycle life and high-rate dischargeability of the composite alloy may be attributed to good catalytic ability of the LaNi 3.55 Co 0.75 Mn 0.4 Al 0.3 alloy, which not only provides the alloy with electrochemical activity, but also hinders the formation of oxide film and decreases the dissolution of V into KOH electrolyte.

Synergism of nano ZnO for improvement of hydrogen absorption performance of Ti-V-based alloys

Effect of nano ZnO on the hydrogen absorption performance of Ti-30V-15Mn-15Cr alloy was investigated. It was found that a small amount addition of nano ZnO (3 wt%) drastically improves the hydrogen absorption property of this alloy powder. The modification enables the air-exposed powder to absorb hydrogen quickly without activation. It could be attributed to the synergetic action of nano ZnO, which might expedite the dissociation of hydrogen on the oxidized alloy surface and play as entrance for hydrogen into the bulk alloy. The fact that nano ZnO addition improves the hydrogen absorption performance of Ti-30V-15Mn-15Cr alloy pioneers a new way for developing highly active Ti-V-based body-centered-cubic phase alloys.