Reversible intercalation of graphite by fluorine: a new bifluoride, C12HF2, and graphite fluorides, C x F (5 > x > 2)

Abstract

A blue-black first-stage graphite fluoride, C_xF (5 > x > 2), in which the planar carbon-atom sheets of graphite are preserved, is made by intercalation of graphite with fluorine in the presence of liquid hydrogen fluoride, at ca. 20 °C, the oxidation (which is electrochemically reversible for x > 2.6) proceeding via a highly conductive second stage salt: C₁₂ ⁺HF₂ ^–.