Electrochemical behavior of SiO_x anodes with variation of oxygen ratio for Li-ion batteries

The development of a method for synthesizing granulated silicon oxide nanoparticles (SiOxNPG) via athermal plasma and water granulation process and determination of the optimum stoichiometry of siliconoxide (SiOx) for achieving high electrochemical performance of an anode based on the developed materialare presented herein. The structure of the SiOxNPGs was confirmed by means of X-ray fluorescence,transmission electron microscopy, and X-ray diffraction. A high initial capacity of ~1196 mA•h•g-1wasachieved using the fabricated SiOxanode with x ~1.06, giving rise to a Coulombic efficiency of 75% afterthe first cycle. Further combination of SiOxwith graphite (3 wt%) for use as an anode gave rise to highcapacity (397 mA•h•g-1) and a very high Coulombic efficiency of 99.99% after 200 cycles. The physicalproperties of the synthesized materials were investigated based on micrometric analysis. On the basisof the volume expansion and cycle capacity, the optimal oxygen ratio of SiOxwas determined to bex ~1.06