Hydriding/dehydriding properties of a series of LaNi₅ based alloys were compared by applying both hydrogen gas phase and electrochemical hydrogen charge/discharge methods. The highest hydrogen absorption capacity of 1.4 wt.% H₂ was found for LaNi_4.3Co_0.4Al_0.3, although LaNi_4.8Sn_0.2 also reveals comparable hydrogen capacity (>1.3%). A significant difference in the hydriding kinetics was observed for all studied alloys before and after activation. The activated alloys (5 cycles at 65 °C, 40 atm. H₂) reach their maximum capacities after less than a minute, whereas the pure LaNi₅ alloy needs several minutes for complete hydriding. The electrochemical hydriding/dehydriding behavior of the alloys reveals superior performance of LaNi_4.3Co_0.4Al_0.3 and LaNi_4.8Sn_0.2 compared to the other compositions studied, as the capacity of LaNi_4.8Sn_0.2 decreases by only 10% for 60 charge/discharge cycles at a current density of 100 mA/g. Good agreement between the hydrogen sorption kinetics of the alloys obtained electrochemically and from hydrogen gas phase has also been observed.

Composites based on Mg₂Ni with 5% activated carbon from apricot stones (ACAP) have been prepared by ball milling and subsequent annealing in hydrogen atmosphere. The purpose of the primary metal (Mg, Ni, and V) milling was to reduce the particle size and achieve a good contact between them, without forming intermetallic compounds. During hydriding/dehydriding at 300 °C the amount of the Mg₂Ni phase progressively increased, and after 10 cycles about 50% Mg₂(Ni,V) was achieved. The hydrogenation produced mainly Mg₂NiH₄, but small amounts of MgH₂ and VH_x were also detected in the powder mixture. Relatively high hydrogen storage capacity and fast hydriding/dehydriding kinetics of the Mg_2.1Ni_0.7V_0.3—5 wt.% ACAP composite were determined both from hydrogen gas phase and electrochemically.

A series of AB₅-type alloys with different particle and grain size were characterized electrochemically as materials for negative electrodes in Ni-MH batteries. Besides, the effect of alloy composition on the discharge capacity and cycle life was studied. Ball milling under hydrogen atmosphere was applied to reduce significantly the grain size of the alloys and to avoid the initial activation at the electrochemical charge/discharge cycling. The alloy morphology and microstructure after different mechanical treatments were characterized by XRD and SEM. The best effect in respect of discharge capacity and cycle life was achieved for the materials milled for 5 h under hydrogen atmosphere.