Towards the realistic silicon/carbon composite for Li-ion secondary battery anode

Аннотация

t A practical and inexpensive method for producing Si/C composite as ready-to-use active material for Li-ion battery anode has been developed. Three-component powders (\63 lm) were synthesized by embedding microsized silicon (8–24 wt%) and synthetic battery-grade graphite (60–75 wt%) in a pitch-derived carbon matrix.The procedure consisted of short mechanical milling of silicon with toluene/pitch suspension followed by mixing with graphite and final heat-treatment at 1,100 C. X-ray diffraction was applied for determining the structural characteristics of the composite and impurities present. A series of anodes were prepared by using CMC and PVDF binder. The dispersion of silicon particles in the carbon matrix and spreading of the binder into the anodic film were monitored using the SEM–EDX technique. Lithium insertion/deinsertion performance was assessed from the galvanostatic charge–discharge characteristics using a Si/ C–lithium two-electrode cell.