Crystallographic and Electrochemical Performances of La<sub>0.73</sub>Ce<sub>0.27</sub>Ni<sub>3.25+x</sub>Mn<sub>0.35</sub>Al<sub>0.15</sub>Cu<sub>0.75</sub>Fe<sub>0.25</sub> (x = 0-0.75) Hydrogen Storage Alloys

Abstract

Microstructuresand electrochemical properties of La0.73Ce0.27Ni3.25+xMn0.35Al0.15Cu0.75Fe0.25 alloys are investigated. XRD results indicate that all alloys are identified with LaNi5 phase with CaCu5 type hexagonal structure, and lattice parameter a, c and cell volume V decrease with increasing x value. Maximum discharge capacity first increases from 286.4 mAh/g (x = 0) to 313.2 mAh/g (x = 0.25), and then decreases to 308.9 mAh/g (x = 0.75). High-rate dischargeability of the alloy electrodes increases when x increases from 0 to 0.75. HRD1200 increases with the increase in the I0 and D, and shows a linear relationship with the I0 and D.