Ion conducting properties of imidazolium salts with tri-alkyl chains in organic electrolytes against activated carbon electrodes

Abstract

Electrochemical double layer capacitors (EDLCs), a type of energy storage device, are currently receiving considerable attention. They have a high power density and good cycle ability. Furthermore, they operate on a simple mechanism where electrical charges in an electrochemical double layer are accumulated at the interface between the electrode and the electrolyte [1-3]. For these reasons, capacitors are used in a wide range of applications such as mobile phones, electrical vehicles, and industry power supplies. Capacitors generally consist of an electrode and an electrolyte. The electrode is prepared using carbon materials such as activated carbon, graphene, or graphite fibers [4-7]. Among the carbon materials, activated carbon, which has a high specific surface area and a large number of pores, is suitable for the capacitor electrode. In particular, it readily absorbs or desorbs electric charge. The electrolyte, meanwhile, can be divided into aqueous and non-aqueous electrolytes. Non-aqueous electrolytes have a wide electrochemical stability of op-erative voltage compare to aqueous electrolytes. Because the window potential is related to the energy density (E = 1/2V