The electronic and electrochemical properties of the LaNi5-based alloys

Abstract

Nanocrystalline La(Ni,M)5-type alloys were prepared by mechanical alloying (MA) and subsequent annealing. The alloying elements of 3d transition metals, Mn, Al and Co were substituted for Ni in LaNi5, and the structural, electrochemical as well as electronic properties were studied. It was found that the partial substitution of Ni by Al or Mn in nanocrystalline La(Ni,M)5 alloy leads to an increase in the discharge capacity. On the other hand, cobalt substituting nickel in LaNi4–xMn0.75Al0.25Cox alloy greatly improved the discharge capacity and cycle life of LaNi5 material. The electronic structure has been studied by the tight binding version of the linear muffin-tin orbital method (TB LMTO) for La(Ni0.8–xCoxAl0.1Mn0.1)5 systems, where x = 0, 0.1, 0.2, and 0.3.