Electrochemical preparation of graphite bis(trifluoromethanesulfonyl) imide

Graphite intercalation compounds (GICs) containing bis(trifluoromethanesulfonyl) imide, N(SO2CF3)(2)(-), are prepared for the first time by electrochemical oxidation of graphite. Electrolytes with nitromethane and ethyl methyl sulfone are used to prepare GICs up to stage 1. The potential-charge curves under galvanostatic or pulse-charge mode show transitions associated with GIC staging, and charge and discharge capacities and charging efficiencies are reported at transition points. The stage 1 GICs have not been prepared before and rapidly decompose in air in the electrolyte. GIC gallery heights and stages are determined by powder X-ray diffraction, and the stage 1 composition is determined by thermogravimetric analysis. Structural and electrochemical properties are compared with those for related GICs. (C) 2001 The Electrochemical Society.