Carbon Fluorides
Carbon monofluoride is denoted as (CF)x and used as a cathode material in one type of primary (non-rechargeable) lithium batteries. It is prepared by reaction of gaseous fluorine with graphitic carbon at 215–230 °C. The color is greyish, white, or yellow. The bond between the carbon and fluorine atoms is covalent. The compound is not electrically conductive which makes the addition of conductive fillers necessary for battery use.
Tetracarbon monofluoride (C4F) is prepared by reacting gaseous fluorine mixed with hydrogen fluoride with graphite at room temperature. The compound has a blackish-blue color.
Read more about this topic: Graphite Intercalation Compound