Contribution of rare-earths to activation property of Zr-based hydride electrodes

The effect of rare earth RE alloying (RE=Ce, Ce-rich mischmetal Mm or La-ri ch mischmetal M1) on the crystalline characteristics and electrochemical pe rformances of AB(2) type (ZrRE)(MnVCrNi)(2) hydride electrodes was investig ated. It is found that RE-alloyed electrodes are activated at the first cha rge/discharge cycle in comparison with 15 cycles needed to activate RE-free alloys. The electrochemical capacity of the RE modified alloy series studi ed is also found to increase by about 15%. The RE modification effect on ac tivation has been discussed on the basis of electrochemical impedance spect roscopy (ETS) measurement and XRD analysis. (C) 1999 Elsevier Science S.A, All rights reserved.