Metal hydride alloys for electrochemical energy source applications

High-capacity conventional and advanced multicomponent metal hydride alloys were synthesized in this work by two different methods. A set of AB ₅ -type intermetallic compounds, with different Al content, were produced by high-frequency vacuum induction melting method, while AB, A ₂B and mixed (AB ₅+Mg) -types composite nanocrystalline-amorphous alloys were obtained mechanochemically by high-energy ball milling in a planetary type mill. The alloys were characterized physically by XRD, SEM and thermodynamically by van't Hoff s plots derived from experimentally obtained PCT isotherms at various temperatures. Different optimized techniques for model electrode preparation from selected metal hydride alloys were also applied. The electrodes were charged-discharged electrochemically in concentrated alkaline solution. In this paper we compare the values for the electrochemical maximum capacity and cycle-life performance of the electrodes prepared by the investigated types of alloys.