Polarization Study of an EDLC Twin Cell with Four-Reference Electrodes

The extra positive electrode of an EDLC where doesn’t face to a negative electrode was known as an easily corroded area. However, the mechanism was not clear. In this paper, in order to simulate an extra positive electrode, two sets of EDLC (Cell 1 and Cell 2) were arranged in a horizontal plane, and the positive electrode of Cell 1 (P1) and that of Cell 2 (P2) were connected or disconnected electrically. Four reference electrodes were embedded around Cell 1 and Cell 2 and electrical potential behavior in a horizontal plane of an EDLC twin cell was studied. With the extra positive electrode (P2), P2 potential shifted to high when charging and discharging the Cell 2, and electric current flow of several mA was observed between P1 and P2. By a simulation study of an electric equivalent circuit of an EDLC twin cell, an ionic movement resistance between P2 and the negative electrode of Cell 1 (N1) was estimated as several hundred ohm. The extra positive electrode (P2) was charged gradually and P2 potential also shifted to high as a result of the simulation study. Reliability of reference electrodes also was studied with the EDLC twin cell with four-reference electrodes.