An investigation on electrochemical hydrogen storage performances of the as-cast and -annealed La0.8−xSmxMg0.2Ni3.35Al0.1Si0.05 (x = 0-0.4) alloys

► The substitution of Sm for La in the A2B7-type electrode alloy was scarcely any reported before. ► The lower Mg content was adopted in order to improve the cycle stability of the alloy. ► The addition of Si in the A2B7-type electrode alloy has not been found to be reported before. ► The as-annealed alloys exhibited very superior electrochemical performances. ► The relationship between the electrochemical performance and the Sm content was provided.