Surface Fluorination and Oxidation of Carbon Materials for Negative Electrode of Lithium Ion Secondary Battery

Abstract

The effect of surface modification of carbon materials on their electrochemical behavior has been studied. Fluorination, ozonization and air-oxidation of carbon surfaces increased the charge-discharge capacities. The change in the d-spacings of carbon materials due to surface modification was negligibly small. XPS measurement indicated that surface oxygen contents slight-ly increased not only in oxidized samples but also in fluorinated one. XPS also revealed the ex-istence of nearly ionic and semi-covalent fluorines at the surface of the fluorinated sample.