The influence of silicon and boron on the electrochemical behaviour of AB(5)-hydrides

AB(5)-type intermetallic compounds were prepared by induction melting and melt spinning. The composition of a stoichiometric compound LaNi3.5Co0.8Mn0.4Al0.3 with a hexagonal CaCu5 structure was varied by stoichiometric and nonstoichiometric addition of Si and B. Discharge capacity is increased considerably by addition of silicon in the range of 0.5-5 at% with a maximum value at about 1%. The highest capacity is achieved by a nonstoichoimetric addition of 3 at% Si. The kinetic properties are additionally improved by the formation of a boron-rich second phase. Copyright (C) 1996 International Association for Hydrogen Energy