Study of ternary FeCl_3-NiCl_2-graphite intercalation compounds synthesized by a molten salt method

Ternary FeCl_3-NiCl_2-GICs were synthesized by the molten salt method, with natural graphite flake used as host and a mixture of NiCl_2 and FeCl_3 as guest. The effect of molar ratio of carbon to metal chlorides, molar ratio of NiCl_2 to FeCl_3, reaction temperature and reaction time on the stage structure and the Ni/Fe molar ratio of the products, as well as the intercalation reaction process of NiCl_2 and FeCl_3 between graphite layers were studied. The results show that ternary FeCl_3-NiCl_2-GICs with different stage structure and molar ratio of Ni to Fe could be obtained through changing the molar ratio of carbon to metal chlorides, molar ratio of NiCl_2 to FeCl_3, reaction temperature and reaction time. The molar ratio of Ni to Fe of the products increased with increasing molar ratio of NiCl_2 to FeCl_3 and intercalation reaction temperature. When the molar ratio of carbon to metal chlorides is 3∶1 and the molar ratio of NiCl_2 to (FeCl_3) is 3∶7, stage one FeCl_3-NiCl_2-GIC was obtained at 400℃ in three days. The intercalation reaction mechanism may be considered as FeCl_3 being gradually replaced by NiCl_2.