Effect of rare earth elements substitution for vanadium on microstructures and electrochemical properties of Ti0.26Zr0.07V0.24Mn0.1Ni0.33 alloy

Abstract

Ti0.26Zr0.07V0.24−xMn0·1Ni0.33REx (x=0, 0.005; RE=Gd, Ho, Er, Yb, Y) alloys hydrogen storage alloy have been prepared and their electrochemical characteristics and microstructure have been investigated. X-ray diffraction results indicated that these alloys consist of main phase V-based solid solution phase and second phase C14 Laves phase. The cell volumes of Bcc phase and C14 Laves phase are different with rare earth elements substitution. It is found that the investigated alloys with rare earth elements substitution show good activation characteristics and high discharge capacity. The alloy Ti0·26Zr0.07V0·235Mn0·1Ni0·33Gd0.005 reaches a maximum discharge capacity of 421mAh·g−1. At high temperature, the discharge capacity of the alloy electrodes with rare-earth elements substitution is higher than norm alloy. However, the cycling stability of the alloys degrades with rare-earth elements substitution.