Nanostructured materials and nanocomposites have inspired many structural and functional applications in recent time. In the last decade, energy-storage devices have employed electrode materials in form of nanomaterials/nanocomposites to yield promising electrochemical performance. The current paper throws light on the application of nanostructured pristine activated carbons as well as chemically modified carbon-halide nanocomposites in practical electrochemical supercapacitors. Pristine activated carbons have been mechanochemically modified via high-energy milling and iodine doping to produce carbon-halide nanocomposites. A significant change in existing physical and electrochemical properties has been marked by introduction of iodine into carbon and the subsequent formation of nanocomposites. The effect of halides and nanoscale morphology is discussed using X-ray, Raman spectroscopy, DSC, BET analysis and electrochemical testing.