Lithium Batteries with Fluorine-Graphite Intercalation Compound Cathodes

Abstract

When the recent papers on fluoro-graphite intercalation compounds are reviewed, it is noticed that it has become possible to control the crystallinity, physical properties and C-F bond character of the fluorine-graphite intercalation compounds CxF by designing and controlling the intercalation of fluorine in a wide range. The relationships have also become clear between the battery performances, such as open circuit voltage (OCV), discharge potential and stability, utilization of the cathode active mass, energy density, etc. and the crystallinity or the C-F bond character of the cathode materials. Because of the higher OCV and much lower overpotential compared with the conventional graphite fluoride cathodes, the CχF cathode with semi-ionic bonding between carbon and fluorine has high discharge potential and high energy density, and draw much attention as a candidate for the post-graphite fluoride cathode. The time has also come for the fluorinegraphite intercalation compounds CχF to be synthesized by designing the functionalities as cathode active material. The advent of a variety of post-graphite fluoride cathodes is expected.