Self-Discharge Processes in Symmetrical Supercapacitors with Activated Carbon Electrodes

The self-discharge of an electric double-layer capacitor with composite activated carbon electrodes and aqueous electrolyte (1 M MgSO4) was studied in detail. Under a long-term potentiostatic charge (stabilization), decrease the discharge capacity observed region voltages exceeding 0.8 V. process consists two phases. In initial phase, cell voltage drop is due to redistribution inside electrodes. During main transfer between determines drop. optimal stabilization time found be 50 min at 1.4 Hydrophilization negative electrode occurred during polarization formation epoxy functional groups.