The cyclic voltammogram for the pure CNT measured at 0.001 Vs -1 (panel c) exhibits the positive peak approximately at 0.1 V, and the two negative peaks approximately at -0.12 and -0.3 V. The peak potentials shift to higher voltages with increasing the scan rate. These peaks can be associated with intercalations or redox reactions. OMIM + can be intercalated into the intersticial channels in the bundled single-wall CNTs, while Cl -can be intercalated or covalently bound to carbon atoms.