Electrochemical properties of chemically processed SiO x as coating material in lithium-ion batteries with Si anode.

A SiO x coating material for Si anode in lithium-ion battery was processed by using SiCl4 and ethylene glycol. The produced SiO x particles after heat treatment at 725°C for 1 h were porous and irregularly shaped with amorphous structure. Pitch carbon added to SiO x was found to strongly affect solid electrolyte interphase stabilization and cyclic stability. When mixed with an optimal amount of 30 wt% pitch carbon, the SiO x showed a high charge/discharge cyclic stability of about 97% for the 2nd to the 50th cycle. The initial specific capacity of the SiO x was measured to be 1401 mAh/g. On the basis of the evaluation of the SiO x coating material, the process utilized in this study is considered an efficient method to produce SiO x with high performance in an economical way.