ELECTROCHEMICAL PROPERTIES OF TIMN2-TYPE ALLOYS BALL-MILLED WITH NICKEL POWDER

TiMn2-type alloys have a high hydrogen storage capacity in reaction with the hydrogen gas, but it is difficult to charge/ discharge them electrochemically as negative electrode materials. In this work, we have found that by ball-milling the alloy powder with a small amount of Ni powder, their electrochemical activity can be stimulated. These ball-milled TiMn2-type alloys in combination with nickel exhibit considerable discharge capacity. SEM and X-ray diffraction analyses indicated that the element nickel was distributed homogeneously on the surface of the amorphous alloy particles. The active nickel clusters presumably catalyze the electrochemical reactions in the negative electrode. The nickel spread on the surface of matrix alloy also increases corrosion resistance of the ball-milled alloys.