Fluorotubes as Cathodes in Lithium Electrochemical Cells

Fluorotubes (C2F) were prepared by fluorinating SWNTs with F2/HF at 250 °C for 12 h and were consequently used as cathode material in a lithium electrochemical cell. The Raman and FTIR spectra of the fluorotubes were investigated before and after the cell was discharged. The discharging performance of the fluorotube/lithium electrochemical cell was studied and compared with that of a carbon monofluoride (CF x )/lithium cell. Thermodynamic calculations using the ΔH f° of fluorotubes and carbon monofluoride indicated that the potential of a fluorotube/lithium electrochemical cell, where the fluorotubes were made by the fluorination of armchair (10,10) SWNTs, should be 0.4 V higher than that of a carbon monofluoride/lithium cell. The experimental results support the theoretical calculations. The relation between SWNT diameter and cell potential was also investigated.