Fluorinated graphites as energetic cathodes for nonaqueous Al batteries

Conventional cathodes utilized in nonaqueous lithium anode batteries, including manganese and vanadium oxides, and molybdenum or titanium sulfides, are incompatible with nonaqueous aluminum anode electrochemical storage processes. Alternative cathodes systems were explored to develop high charge capacity nonaqueous aluminum cells. A series of high storage capacity Al cells, utilizing cathodes composed of CFx fluorinated polymer graphite compounds are demonstrated. Significant CFx cathodic capacities are obtained in aluminum anode cells utilizing a 0.3 M tetraethylammonium chloride, 10 mM Hg( CH3COO)(2) acetonitrile electrolyte. The addition of hydroxide to the CFx cathode mixture increases discharge potential, while the addition of nonfluorinated 1 mum graphite increases measured cathodic capacity. The CFx cathode capacity increases with the degree of fluorination from 27 to 35% fluorine, is approximately constant from 35 to 58% fluorine, increases in capacity for 61% fluorine, and increases again with 63% fluorine (the highest available level of 63% fluorine available in the CFx). Measured cathode capacities exceed 250 mAh g(-1). For example, in excess of 300 mAh g(-1), total cathode mass is measured for a 50: 50 wt % cathode composite containing 55% fluorinated CFx and half 1 mum nonfluorinated graphite. (C) 2002 The Electrochemical Society.