| 초록 |
Silicon has a high theoretical capacity as lithium ion battery (LIB) anode, but which exhibit rapid capacity fading due to large volume expansion during Li+ insertion and extraction processes upon cycling. In this study, to prevent volume expansion, silicon was carbon coated using quinoline insoluble (QI)-free mesophase pitch. Silicon fluorinated by F2 gas in room temperature and surface property was investigated by X-ray photoelectron microscopy (XPS). Then fluorinated silicon was carbon coated with QI-free mesophase pitch using heat-treatment at 1000 ℃ for 1 h. Amount of carbon coating was investigated by thermogravimetric analysis (TGA), and their surface morphology observed by scanning electron microscope (SEM). Amount of carbon coating increased by improving surface energy of silicon through fluorination. LIB coin cell was fabricated with carbon coated-fluorinated silicon as anode and Li metal as cathode, and electrochemical properties were investigated by charge/discharge test. |
