Attractive electrode properties of LaNi4.5Co0.4Al0.1 hydrogen-absorbing alloy

Promising metal hydride electrode performance of LaNi 4.5 Co 0.4 Al 0.1 , prepared by induction melting and next hydrogen-induced decrepitation, was proven in the present study. Both the composition and microstructure of the electrode material were found to be responsible for its reliable hydrogen capacity and cycle stability. After prolonged exposure to air, the alloys retain their high hydrogen sorption characteristics, revealing only 10% capacity reduction. The gas phase hydriding of the alloys confirms the hydrogen capacity obtained under electrochemical conditions. Furthermore, the influence of C, Co, and Co 3 O 4 additions to the LaNi 5 -based alloy on the hydrogen electrode performance was also elucidated. The highest capacity of 300 mAh g −1 , remaining constant for 20 cycles, was obtained for LaNi 4.5 Co 0.4 Al 0.1 + 15 mg Co 3 O 4 . This material maintains excellent capacity also at high current densities, making it a suitable electrode material in Ni/MH batteries.