The electrochemical properties of a new hydrogen storage alloy Ti3Ni2 have
been studied in detail. The results show that the discharge capacity of Ti3
Ni2 alloy reaches 384.4 mA h/g (corresponding to Ti3Ni2H3.7) at 353 K and 1
45.5 mA h/g (corresponding to Ti3Ni2H1.47) at 278 K. At the higher temperat
ure (353 K), two plateaus appear on the discharge curve, and at the lower t
emperature (278 K) only one plateau. The kinetic property of Ti3Ni2 alloy e
lectrode is poor, The following properties, namely the retention of charge,
the activation of alloy, the kinetic property of Ti3Ni2 alloy (including t
he exchange current, the diffusion coefficient of hydrogen and high-rate di
schargeability) can all be improved by increasing the temperature. It can b
e seen from X-ray diffraction analysis that two phases exist in alloy: name
ly the cubic Ti2NiH phase with Fe3W3C structure and the cubic TiNiH phase f
or the alloy cycled in alkaline solution, and the cubic Ti2NiH0.5 phase wit
h Fe3W3C structure and the cubic TiNiH phase for the alloy hydrogenated wit
h gaseous hydrogen. (C) 2001 International Association for Hydrogen Energy.
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