Intercalation of AlCl 3 into FeCl 3-graphite intercalation compounds and occurrence of BI-intercalation

Abstract

The formation process of the ternary AlCl 3-FeCl 3-graphite intercalation compounds (GICs) was studied by using three different reaction paths at 150°C. In the reaction of stage 1, FeCl 3-GICs with AlCl 3, the exchange of intercalated FeCl 3 for AlCl 3 occurred and, consequently, the formation of the “mixed”-type ternary GIC was observed at the edge of the flakes. The reaction of stage 2 FeCl 3-GIC with AlCl 3 however, gave the “bi-intercalation”-type GIC due to intercalation of Aid, into unoccupied graphite galleries. In the reaction of the host graphite with an equimolar mixture of AlCl 3 and FeCl 3 the preferential intercalation of AlCl 3, was observed in the beginning of the reaction, and then the exchange of AlCl 3, for FeCl 3 in the stage 1 compound occurred. Through the determination of the charge density distribution and the structural refinement by a pattern-fitting technique on mixedand bi-intercalation-type GICs, the former was found to have more defective intercalate layers than the latter.