Chromium Oxides as Cathodes for Secondary High Energy Density Lithium Batteries

The electrochemical reduction and reoxidation of , , thermally decomposed , and a commercially available preparation are compared in organic Li⁺ electrolytes. All these cathode materials reveal an average discharge voltage of approximately 3V vs. a lithium anode and a maximum charge transfer exceeding one electron per Cr atom. The basic general discharge reaction is shown to be the reduction of higher chromium oxides with . itself does not represent a suitable cathode material. From structural considerations it is concluded that the electrode processes are likely to be topotactic reactions of chromium oxides, yielding ternary phases which can be reoxidized with high coulombic efficiency.