A New Niobium Selenide Cathode for Nonaqueous Lithium Batteries

The ..gamma..-''NbSe/sub 4/'' phase, with a single phase composition range NbSe/sub 4/./sub 0/ to NbSe/sub 4/./sub 5/, is shown to behave as an electrochemically active, reversible cathode material in nonaqueous lithium cells. The cell data, together with the results of n-butyl lithium reaction studies, indicate a topotactic reaction to give an Li/sub 4/NbSe/sub 4 + x/ (x = 0 to 0.5) discharge product. Cycle data are presented for nonaqueous lithium cells with cathodes of either NbSe/sub 4/ containing small amounts of fibrous NbSe/sub 3/ or hot-pressed composites of NbSe/sub 4 + x/ with graphite and polyethylene. 9 figures.