Hydrogen absorption behavior of multicomponent zirconium based AB2 alloys with different chromium-vanadium ratio

H. A. PERETTI; A. VISINTIN; L. V. MOGNI; H. L. CORSO; J. ANDRADE GAMBOA; D. SERAFINI; W. E. TRIACA

JOURNAL OF ALLOYS AND COMPOUNDS

Elsevier Science

Lugar: New York USA; Año: 2003 vol. 354 p. 181 - 186

0925-8388

Recent developments on new electrode materials for nickel–metal hydride batteries include Laves phases based on ZrCr with multiple substitutions to improve the electrode performance. In this work, results on the hydrogen absorption behavior of the Zr Ti NiMn Cr V alloy (with 0#x#0.5) obtained by volumetric and electrochemical techniques are presented. The structural and morphological characterization of the alloy is also studied by X-ray powder diffractometry (XRD) and scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS). The (PCT) curves show a high hydrogen storage capacity expressed as hydrogen atoms per formula unit (H/F.U.|3.6), and a steep slope rather than a horizontal plateau corresponding to the two-phase equilibrium. Electrode activation was achieved by voltammetric cycling between preset potentials in alkaline solution. Discharge capacities of about 340 mAh /g are found for high Cr /V content ratios, whereas the high-rate dischargeability significantly decreases on increasing the Cr content in the alloy.