Electrochemical studies on AB(2) type Zr0.5Ti0.5V0.6Cr0.2Ni1.2 metal hydrid
e electrodes with varying particle size suggests that the electrodes with a
lloy particles of about 60 mu m yield the optimum performance. The values f
or diffusion coefficient of hydrogen in the alloy particles > 25 mu m are f
ound to be nearly invariant. Both a.c. impedance and linear polarization da
ta on electrodes with varying particle size suggest that the charge-transfe
r resistance depends on state-of-charge of the electrodes. A comparison of
scanning electron micrographs of fresh electrodes and subsequent to their p
rolonged charge-discharge cycling suggests that the metal hydride particles
develop stress-induced cracks owing to their inherent expansion and contra
ction during the hydriding/dehydriding processes.