Ultrasonic-Assisted Synthesis of Silicon/Exfoliated-Graphite Nanocomposite as Anode Material for Lithium-Ion Batteries

ABSTRACT: Currently, lithium-ion batteries have the highest energy density; hence naturally, this chemistry is the most promising solution for high-density energy storage. This means the commercially used anode material, that is, graphite with a theoretical capacity of 372 mAh/g, needs to be improved; hence the implementation of more capacity material is needed. In regard, silicon is the best alternative available for this with ~4200 mAh/g theoretical capacity. In this work an industrially scalable procedure using ultrasonication followed shear mixer to synthesize a composite of ball-milled silicon with exfoliated graphite for the anode material in lithium-ion batteries. The material is characterized using X-ray diffraction for crystallite information, and scanning electron microscopy shows the composite visuals with X-ray photoelectron spectroscopy to indicate bonding details in the composite, along with half coin-cell tested for18 cycles with a capacity of 222.48 mAh/g and columbic efficiency of 97.86%. Hence the silicon/exfoliated graphite composite using 2 step ultrasonic and shear process can be economical and scalable.