Synthesis and characterization of graphite/silicon composites for energy storage in lithium batteries
LOTA G., WALKOWIAK M., LOTA K.

Please cite as: CHEMIK 2013, 67, 11, 1130–1137

Graphite/silicon composites have been prepared by a high energy ball milling. Si content varied from 5 to 50% in relation to the whole material. All composites have been characterized physicochemically by X-ray diffraction and SEM observations. Impact of ball-milling on the formation of C/Si composites and structural degradation of their components has been studied and discussed. It has been demonstrated that ball-milling process generates a high degree of structural disorder in single components as well as in composi tes which is evidenced by a high irreversible capacities observed in electrochemical experiments. Composite anode material with 20% content of silicon seems to be optimal from all the tested sam ples, delivering the reversible capacity of 293 mAh/g in 50th charge/ discharge cycle. Improved cyclic performance has been observed when electrochemical lithium insertion cut-off voltage was set as Li/Li+. 15 mV vs.Keywords: Li-ion batteries, silicon/graphite composites, ball milling

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