Physical and electrochemical properties of iodine-modified activated carbons

Carbon and activated carbons have been halide modified through the mechanochemical incorporation of iodine. The effect of the processing and chemical modifications on the physical and electrochemical properties was examined. Distinct evidence was obtained to support significant structural and electrochemical modification of iodine-modified carbon nanostructures vs unmodified nanostructures. The resulting materials show an interesting combination of lower surface area coupled with markedly higher volumetric and gravimetric electrochemical capacity. The incorporation of halide leads to a 200-400% increase in volumetric capacitance of carbon materials. This modification is discussed in the context of electronic modification of the carbon and the impact on non-faradaic and also pseudocapacitive reactions for use as positive electrodes in nonaqueous symmetric and asymmetric electrochemical capacitors. (c) 2007 The Electrochemical Society.