Electrochemical properties of CeMg_(11)Ni+x% Ni composites (x=0,50, 100 and 200) prepared by ball-milling

1　INTRODUCTIONMagnesium and magnesium based alloys arepromising hydrogen storage materials because oftheir absorbability of hydrogen in large quantities,low specific gravity, rich mineral resources, lowmaterial cost and so on. Nevertheless, their hy drides are too stable to be used at room tempera ture[1]. It seems impossible for application of crys talline Mg based alloys in nickel hydrogen batter ies.It is well known that amorphous alloys havemany advanta…

Electrochemical properties of CeMg11 Ni+ x % Ni composites (x=0, 50, 100 and 200) prepared by ball-milling

The electrochemical properties of the as-cast CeMg11 Ni and ball-milled CeMg11 Ni x% Ni(x = 0, 50,100 and 200, mass fraction) composites were investigated. The results show that homogeneous amorphous phase of CeMg11 Ni x% Ni composite can be obtained by ball-milling, and discharge capacity of the ball-milled CeMg11 Ni x% Ni composites differs greatly depending on the amount of Ni introduced during milling. The CeMg11 Ni 200% Ni composite after 90 h ball-milling was found to exhibit a large discharge capacity of about 1 012 mAh/g at 303 K,and it also shows better charge-discharge cycling stability than those with lower Ni content. This remarkable improvement in electrochemical properties of the ball-milled composites seems to be attributed to the formation of an amorphous composite as well as the improvement of the surface state of the ball-milled particles.