Abstract: The effect of La alloying on the crystalline characteristics, electrochemical capacity and activity of AB2 type Zr-Cr-Ni hydride electrodes was investigated. It was found that La alloying was able to shorten the activating process from 15 cycles of La-free alloy to 2 cycles, and that the main phase shifts from C14 to C15 by XRD analysis. It may be attributed to the modification of surface chemical states and change in internal microstructures. However, the cycling stability was also found to degrade severely for La-containing hydride electrode because of the collapse of its distorted lattice.

Key words: Zr-Cr-Ni hydrogen storage alloy, La alloying, electrode performance