Electrical conductivity and air stability of FeCl3, CuCl2, MoCl5, and SbCl5 graphite intercalation compounds prepared from flexible graphite sheets

In this study, four graphite intercalation compounds (GICs) of metal chlorides, such as FeCl3, CuCl2, MoCl5, and SbCl5, were synthesized from two graphite sheets, and their electrical conductivity and air stability were accurately measured under standardized experimental conditions. After the exposure of these GICs to air, changes in their electrical conductivities and structures were recorded as a function of time. Three decomposition modes were observed. CuCl2-GICs did not decompose, and MoCl5-GICs prepared from a graphite sheet manufactured from a polyimide film (PGS) were also highly stable in air; on the other hand, immediate, extensive degradation was observed for FeCl3-GICs, while the SbCl5-GICs transformed to higher-stage (diluted) compounds. Thus, the air stability of these GICs varied with the metal chloride and host graphite used; however, their electrical conductivities prior to decomposition varied only with respect to the host graphite. Among the highly air stable, conductive compounds prepared herein, the MoCl5-GICs prepared from PGS demonstrate the highest potential for practical applications. This study reveals that highly conductive, air stable metal chlorides GICs can be synthesized.