Charge/Discharge Characteristics of Carbon Fiber with Graphite Structure in Organic Electrolytes Containing Lithium Trifluoromethanesulfate and Lithium Hexafluorophosphate

Abstract

The electrolytic conductivities of lithium trifluoromethanesulfate and lithium hexafluorophosphate have been investigated as a function of the solvent composition. The organic solvent tested was ethylene carbonate (EC) or propylene carbonate mixed with 1,2‐dimethoxyethane, diethyl carbonate, or dimethyl carbonate (DMC). For each solvent system, the electrolytes containing showed nearly half the values of the conductivity of the corresponding systems with . High discharge capacities (ca.ca. 200 mAh g⁻¹) for charge‐discharge cycling of the carbon fiber electrode with a graphite structure were obtained in electrolytes. Especially, the highest coulombic efficiency (98%) was obtained in the system. The EC‐based electrolyte systems containing were found to be more compatible with the carbon fiber electrode than the systems containing .