리튬이온배터리 음극활물질 Li4Ti5O12의 전기화학적 특성에 미치는 F 도핑 효과

Abstract

We have expected that F doping in spinel LTO will improve the electrochemical performance along with electronic conductivity. The pristine Li4Ti5O12 and fluorine anion substituted Li4Ti5O12-xFx (x=0.1 and 0.2) powders are synthesized by sol-gel method and verified physical and electrochemical properties. The cubic lattice parameters increases with increasing the amount of F doping. The substitution of F ion is possible to improve the electronic conductivity of LTO because of the generation of mixed valence state of Ti3+/Ti4+. However, the more amount of F doping increase, the gap between the anodic peak and cathodic peak more increase because of inductive effect of F doping. In addition, the F doping is having a negative influence on the electrochemical performance of spinel LTO. Therefore, the electronic conductivity improved, on the contrary, the electrochemical performance turns for the worse with the doping of fluorine content.