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

TiMn2-type alloys have a high hydrogen storage capacity in reaction wi th the hydrogen gas, but it is difficult to charge/ discharge them ele ctrochemically 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-m illed TiMn2-type alloys in combination with nickel exhibit considerabl e discharge capacity. SEM and X-ray diffraction analyses indicated tha t the element nickel was distributed homogeneously on the surface of t he amorphous alloy particles. The active nickel clusters presumably ca talyze the electrochemical reactions in the negative electrode. The ni ckel spread on the surface of matrix alloy also increases corrosion re sistance of the ball-milled alloys.