Investigations on experimental data obtained by Electrochemical Impedance Spectroscopy on Supercapacitors Structures

Supercapacitors or double-layer electrochemical capacitors (EDLCs) that have a very good dynamic management of stored electrical charge do not contain lead or other polluting materials. EDLCs have a very long life (hundreds of thousands of charge-discharge cycles), the operating temperature range is longer than that of batteries and have a fairly high power density which allows jumps of current when required in various applications. Thus, supercapacitors are a viable solution for their use in an energy storage system, but the operation of this component must be known down to the smallest detail. For this, the identification of useful parameters in applications, such as series equivalent resistance, capacitance, maximum working voltage becomes useful to have a better management of the functionality of the component in applications [1]. Moreover, in the case of supercapacitors, the parameters are determined by the materials from which they are made, and in order to try to obtain the most reliable option and to have the best possible control over the parameters, a series of supercapacitors, coin cell type CR2032, have made using different materials, different amounts of material, but also two different methods of depositing the active material. In order to identify the specific parameters (electrolyte solution resistance, charge transfer resistance and double layer capacitance), calculations were performed on the experimental data obtained using electrochemical impedance spectroscopy (EIS).