EFFECT OF CE, CO, AND SN SUBSTITUTION ON GAS-PHASE AND ELECTROCHEMICAL HYDRIDING DEHYDRIDING PROPERTIES OF LANI5

A number of LaNi3-based intermetallics with Ce, Sn, and Co substitutions were prepared by the are-melting technique and tested as electrodes in Ni/MH(x) batteries. Sn and Co substitution expand the unit cell and lower the plateau pressures whereas the introduction of Ce results in the reverse effects. Ce and Co substitutions result in a decrease in the storage capacity of the intermetallics. Most of the Sn substituted compounds exhibit high hydriding capacities, though they widely differ in their electrochemical behavior, viz., cycle life and rate capabilities. Two such intermetallic compounds, with different amounts of substitution, show promise with high capacities (over 300 mAh/g), even at high rates of discharge. Intermetallics with Ce, Sn, and Co retain the high capacity upon long-term cycling.