A new electrode consisting of Prussian blue/Dibenzo-18-crown-6 ion-pair complex for electrochemical capacitor applications

A new electrode consisting of iron(III) hexacyanoferrate(II) known as Prussian blue and Dibenzo-18-crown-6 macrocycle ion-pair complex formed in presence of chloroform was studied for its electrochemical behavior in 0.1 M KCl solutions. The ion-pair complex exhibited cyclic voltammetric response combining the Faradic redox characteristics of Prussian blue and the non-Faradic capacitance behavior of crown ether. Pseudo-capacitance values from the cyclic voltammetric measurements of the ion-pair complex showed a nine-fold increase as against the crown ether and a 1.5 times increase compared to Prussian blue. The ion-pair complex was chemically and electrochemically stable up to the cycled 1000 runs. Double potential step chronocoulometric measurements done at the lowest time scale of 10 s showed specific capacitance value of 28.95 × 103 F g−1 for the reduction step and 52.92 × 103 F g−1 for the oxidation step. Such pseudo-capacitive values are the requisite of electrochemical capacitors that can provide huge power pulse within a very short time.