Host effect on the formation of sodium-tetrahydrofuran-graphite intercalation compounds

The formation of sodium-tetrahydrofuran-graphite intercalation compounds (NaTHFGICs) in THF solution with sodium and naphthalene by using various kinds of host carbon materials was investigated and the criteria of the hosts were discussed. Hosts with high crystallinity gave a well-defined stage-1 structure and its formation was very slow. Two phases of stage-1 structure with different Ic values, 1.12 and 0.72 nm, were obtained, the latter being formed after exposure to air. Hosts with low crystallinity, on the other hand, quickly formed undefinable stage structure. A clear criterion for the relation between crystallite thickness Lc(002) and degree of graphitization P1 was difficult to determine.