Electrochemical hydriding of amorphous and nanocrystalline TiNi-based alloys

Amorphous and nanocrystalline TiNi1−xMx (M = Co, Fe, Sn; x = 0 and 0.2) alloys were synthesized by mechanical alloying. Powder particles with an average diameter of about 5 μm were produced. X-ray diffraction analysis showed that after 10.5 h of milling the initial mixture of metal powders transformed into amorphous or fine nanocrystalline material. DSC analysis displayed high thermal stability of the as-milled amorphous alloys. Electrochemical hydrogen charge/discharge measurements of the as-milled as well as annealed alloys were carried out at galvanostatic conditions. It was found that among the alloys studied TiNi0.8Fe0.2 revealed the highest discharge capacity of about 65 mAh/g in the as-milled state and 80 mAh/g after annealing at 500 °C.