Graphite fluoride, with the chemical formula (CFx)n

Graphite fluoride, with the chemical formula (CFx)n where 0 < x < 1.25, is a derivative of graphite that has been fluorinated, resulting in a unique set of properties. It is known for its excellent lubricant properties, high thermal and chemical stability, and extremely low surface energy. The structure of graphite fluoride consists of flat carbon layers similar to those in graphite, with fluorine atoms bonded above and below the carbon layers. The composition of graphite fluoride lies within the range C3.6F to C4F, and it is characterized by its velvety black color, sometimes with a bluish tint.

The fluorination process changes the sp2 hybridization state of the carbons in graphite to sp3, which significantly affects the material's electronic properties. This alteration opens the band gap at the Dirac K point and leads to a loss of the π-conjugated electron cloud above and below the graphene plane. Graphite fluoride is also noted for its resistance to acids, bases, and common organic reagents, and it slowly decomposes when heated for long periods above 100°C. It is an electrical insulator, but the formation of a carbon film around the surface of graphite fluoride particles can decrease the initial overpotential without a significant decrease in capacity when used in battery applications.

In terms of applications, graphite fluoride is used in cathodic materials, lubricants, image recording, pressure-sensitive copying, and carbon filament incandescent lamps. Its unique properties also make it a candidate for use in super-hydrophobic films and electrode active materials. The interlamellar space of the graphite layers is increased by the intercalation of fluorine atoms, reducing the interlayer binding force and making the material an excellent solid lubricant. Graphite fluoride's plate-like structure and the ability of its platelets to slide against each other make it a promising material for the development of high-performance polymer composites.