In present work, for improving the electrochemical performance of conductive polymer, POAP/1-octade cyl-3-methylimidazolium Bromide ([OMD]Br) composite films have been fabricated by POAP electropolymerization in the presence of [OMD]Br as active electrodes for electrochemical supercapacitors. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. Analyses of DFT results show that the atomic-scale electronic properties are generally depend on the bonding and electronic molecular structures (and thus their variation with the external bias in real nano-electrochemical circuits). The supercapacity behavior of the composite film was attributed to the (i) high active surface area of the composite, (ii) charge transfer along the polymer chain due to the conjugation form of the polymer and finally (iii) synergism effect between conductive polymer and [OMD]Br. (C) 2017 Elsevier Inc. All rights reserved.