The electrochemical properties of the as-cast CeMg11Ni and ball-milled CeMg11Ni+x% Ni（x=0, 50, 100 and 200, mass fraction） composites were investigated. The results show that homogeneous amorphous phase of CeMg11Ni+x% Ni composite can be obtained by ball-milling, and discharge capacity of the ball-milled CeMg11Ni+x% Ni composites differs greatly depending on the amount of Ni introduced during milling. The CeMg11Ni+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.
In this paper,the microstructure and hydrogen storage properties of the（NaH/Al）+x（molar fraction,%） Ti（x=0,4,6, 10） composites were investigated.It was found that the reversible hydrogen storage properties can be improved by mechanically ball-milling the（NaH/Al） mixture together with Ti powder.H2 is a better ball-milling atmosphere than Ar,because a part of NaH is consumed during the ball-milling under an Ar atmosphere.As the Ti content increases,the hydrogen storage properties are enhanced gradually.In case of x=10,the reversible hydrogen absorption/desorption capacities of the composites milled for 6 h under the H2 atmosphere reach 4.01% and 3.93%（mass fraction）,respectively.The catalytic mechanism of the Ti-doped NaH/Al composites system is discussed briefly.
