Structural and Electrochemical Hydriding Characteristics of Mg–Ti-Based Alloys Prepared by High Energy Ballmilling

Abstract

alloys, with ranging from 20 to 80, were prepared by ballmilling. Except for , a complete mechanical alloying between Mg and Ti was observed. X-ray diffraction analyses combined with Rietveld refinement show that the as-milled alloys are made of a mixture of hexagonal close-packed (hcp) and body-centered cubic (bcc) phases in various proportions and compositions depending on the Mg/Ti ratio in the initial mixture. Their hydrogen storage characteristics were investigated electrochemically in a KOH electrolyte. The number of activation cycles and the maximum discharge capacity value are strongly dependent on the material composition. The highest hydrogen discharge capacity is obtained with the electrode. Structural analyses of a cycled electrode show that both hcp and bcc Mg–Ti phases are transformed into a face-centered cubic phase upon cycling.