The structure and electrochemical characteristics of Ni substitution for Mn and Al in AB2-type CeMnAl intermetallic compounds are studied. XRD and SEM reveal that Ni partial substitution leads to a phase change of the alloys and new phase to be formed. The electrochemical activity of CeMn1-xAl1-xNi2x (x=0.00, 0.25, 0.50 and 0.75) alloy is greatly improved and the discharge capacity can increase from 17.93mAhg-1 (x=0.00) to 118.3mAhg-1 (x=0.75) at 298K and from 68.42mAhg-1 (x=0.00) to 216.1mAhg-1 (x=0.75) at 328K, respectively. The electrochemical P–C–T curve shows that no hydrogen equilibrium pressure plateau is observed for CeMnAl alloy while the slope of the plateau becomes flatter and longer with increasing Ni content.