Electrochemical study of the reversible hydrogen storage in CeTi2Cr4Ni5-based metal hydride alloys

A novel PuNi3-type intermetallic compound CeTi2Ni5Cr4 is elaborated by mechanical alloying and investigated as a negative electrode material for nickel-metal hydride (Ni-MH) batteries. The synthesis reaction is performed from pure AB5-type CeNi5 and AB2-type TiCr2 intermetallic precursors. The crystallographic parameters of prepared compounds are calculated by the Rietveld refinement of X-ray diffraction (XRD) patterns for powders ball-milled between 2 and 20 h. The highest content of CeTi2Ni5Cr4 phase is 51 wt.% in powder elaborated after 8 h of milling time. The reversible hydrogenation of CeTi2Ni5Cr4 -based electrodes is characterized electrochemically in the presence of alkaline electrolyte at room temperature. The maximum discharge capacity is 205 mAh g−1 and the average capacity retention is 84% upon 30 charge/discharge cycles, demonstrating the suitable electrochemical behavior of CeTi2Ni5Cr4. Competitive hydrogen diffusion rates are also obtained in the range of (1.9-10.5) 10−10 cm2 s−1.