Synthesis and study of structural, morphological and electrochemical properties of TiFe1-xCox hydrogen storage alloys

Nanocrystalline and amorphous AB-type hydrogen storage alloys with composition TiFe1-xCox (x = 0.1 and 0.3) were synthesized by mechanical alloying. The microstructure and the morphology of the alloy powders obtained were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD analysis showed that the samples are with composite microstructure. The SEM analysis showed that the alloy powders consist of agglomerations (10 - 15 μm) of smaller particles (1 - 5 μm) cold-welded together. The particle size distribution is in the range of 1 - 15 μm, with a maximum at about 5 - 6 μm. It depends on both time of milling and the amount of Co in the TiFe1-xCox composition. The electrochemical cycle life tests of the electrodes showed that the alloys containing Co possess lower maximum discharge capacity and better corrosion stability, as compared with those measured for the TiFe electrode.