Effect of ionic liquids on the capacitance behaviors of activated carbon electrodes against organic electrolytes

Organic electrolytes were prepared by using a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) as solvent, tetraethylammonium tetrafluoroborate (TEABF₄) as a main salt, and a different content of 1-ethyl-3-buthyl imidazolium tetrafluoroborate (BMImBF₄) as an additive. The aim of present paper is to study properties of electrolyte/electrode interface based on the mixed organic electrolyte by adding a BMImBF₄. The morphology of carbon electrode cycled in prepared electrolytes was investigated by scanning electron microscopy (SEM). The ionic conductivity of the electrolytes was measured, and the electrochemical performances of the electrolytes were evaluated by using cyclic voltammetry. By using the BMImBF₄ salt, the interfacial resistance was decreased and the capacitance and the ionic conductivity were increased.