Effect of rapid solidification process on the alloy structure and electrode performance of Zr(Ni0.55V0.1Mn0.3Cr0.55)(2.1)

The crystal structure, microstructure, phase abundance and electrochemical properties of Zr(Ni0.55V0.1Mn0.3Cr0.55)(2.1) prepared by the melt spinning method were studied. The results show that the discharge capacity decreases , the number of activation cycles increases and the electrochemical cycle l ife prolongs while the cooling rate of the hydrogen storage alloy ribbon in creases. We discovered a new microstructure, microcrystalline C14 Laves pha se in the experiment. The amount of the microcrystalline C14 Laves phase in creased with the cooling rate of alloy ribbons. A more detailed study also showed that the electrochemical properties changed with phase abundance (C1 4 or C15) of alloys prepared at different cooling rates. The phase abundanc e change of microcrystalline C14 or C15 Laves phases resulted in a discharg e capacity change. The increase in phase abundance of the microcrystalline C14 Laves phase had a negative effect on the discharge capacity and activat ion process, and a positive effect on the cyclic life of the melt spun allo ys. (C) 1999 Elsevier Science S.A. All rights reserved.