Cathodic Discharge of Graphite Intercalation Compounds in Organic Electrolytes.

摘要

A survey of graphite intercalation compounds with cathodic depolarizer capability showed that two groups, graphite fluorides and graphite oxides, offer theoretically 9000-1500 W-hr/lb of cell reactants in lithium batteries. The attractiveness of these compounds is further enhanced by their practical insolubility in the electrolytes of interest. Mechanically stable cathodes were prepared from tetracarbon monofluoride, carbon monofluoride, and graphite oxide. Galvanostatic current-potential curves of the cathodes in 1M LiClO4 propylene carbonate electrolyte were measured at 30 C. The current-potential curves of the intercalation compounds were compared with that of cathodes prepared in the same fashion but containing manganese dioxide as the depolarizer. Galvanostatic discharge curves showed that 100% reduction of the cathodic depolarizers can be achieved. This is followed by solvent reduction which led to an apparent increase in utilization over 100%. By graphical integration of the cathodic and cell discharge curves, a comparison of the energy content (watt-hour/pound of depolarizer and watt-hour/pound of cell components) of the depolarizers as a function of rate, per cent utilization, electrolyte anion and solvent was made. Considering the essential cell component weights, up to about 150 W-hr/lb of battery components can be expected in practical lithium/carbon monofluoride batteries. (Author)