Hydrogen Storage Properties of As-Cast and Annealed La1.9Ti0.1MgNi9 Alloys

La1.9Ti0.1MgNi9 alloys were prepared by magnetic levitation melting followed by annealing treatments. The results of XRD, PCT and electrochemical measurements show that all samples possess a multiphase structure, and LaNi5 phase is the main phase. LaMg2Ni9 phase disappears and Ti2Ni phase appears at 1173 K. Annealed alloys exhibit higher compositional homogeneity and lower absorption/desorption plateau pressures compared to as-cast alloy. The effective hydrogen storage capacity of the alloy annealed at 1073 K is the highest, and it reaches 1.25% (mass fraction) at 303 K. Annealing not only enhances the discharge capacity, but also improves the cyclic stability and the high rate dischargeability markedly. La1.9Ti0.1MgNi9 alloy annealed at 1173 K presents good electrochemical performance with the maximum discharge capacity of 377 mAh/g, the HRD1100 of 0.839 and the retention of discharge capacity of 60% after 112 charge/discharge cycles.