The structural and thermal stability, electrochemical hydrogenation and corrosion behavior of LaT5−xMx(T = Co, Ni and M = Al, Ge, Li) phases

Abstract

The structural and thermal stability, electrochemical hydrogenation and corrosion behavior of LaT5−x(M/Li)x (T = Co, Ni and M = Al, Ge) alloys have been investigated using x-ray diffraction, SEM with WDS/EDX, DSC and electrochemical techniques. The prepared ternary and quaternary samples are solid solutions on the base of binary LaCo5 and LaNi5 compounds with hexagonal CaCu5 structure type. By partial substitution of transition metals (Ni and Co) by Al, Ge and Li in the LaT5−x(M/Li)x alloys the discharge capacity increased by 25%. Doping of LaCo5 and LaNi5 binary phases by Al, Ge and Li improves corrosion resistance, thermal stability and absorption capacity during the electrochemical hydrogenation. These alloys passivate effectively in strong alkaline solution.