Si–AB5 composites as anode materials for lithium ion batteries

The Si–AB5 (MmNi3.6Co0.7Al0.3Mn0.4 alloy) composites with a high tap density as anode materials for lithium-ion batteries were synthesized by ball-milling. Si nanoparticles are distributed homogeneously on the surface of the AB5 matrix. The electrochemical performance of the Si–AB5 composites as a function of Si content was investigated. It is demonstrated that the Si–AB5 composite delivers a larger reversible capacity and better cycle ability because the inactive AB5 alloy can accommodate the large volume changes of Si nanoparticles distributed on the surface of the Si–AB5 composite during cycling. In particular, the Si–AB5 composite containing 20 wt% Si with the high tap density of 2.8 g/cm3 obtained after ball-milling for 11 h exhibits an initial and maximum reversible (charge) capacity of 370 and 385 mAh/g. The high capacity retention can be achieved after 50 cycles in the potential range from 0.02 to 1.5 V.