Ball milling of graphite/tin composite anode materials in a liquid medium

C/Sn composites were prepared by shock-type ball milling in liquid media, showing excellent cycleability as anode materials for Li-ion batteries. X-ray diffraction and SEM observation showed that graphite became amorphous and the nano-dispersed metal tin was embedded in the ductile graphite matrix after intensive ball milling. Incorporated tin provided higher capacity for lithium insertion, which was attributed to the reaction of tin with Li to form Li _xSn alloys. The amorphous graphite matrix buffered the volume expansion of tin alloy with lithium during cycling, leading to stable cycleability of the composite. The C_0.9Sn_0.1 composite presented initial discharge capacity of 1480 mAh g^-1 and a stable cycling capacity of 630 mAh g^-1 in the following cycles. The lithium storage capacity of 575mAh g^-1 was still remained after 45 cycles. The composite of graphite and tin is a promising alternative anode material with high capacity for lithium-ion batteries.