Electrochemical Properties of Nanoporous Carbon Material in Aqueous Electrolytes

Abstract

The paper is devoted to the study of the behavior of capacitor type electrochemical system in the К+-containing aqueous electrolytes. Nanoporous carbon material (NCM) was used as the electrode material, obtained by carbonization of plant raw materials with the following chemical activation. Optimization of pore size distribution was carried out by chemical-thermal method using potassium hydroxide as activator. It is shown that obtained materials have high values of capacitance which is realized by charge storage on the electrical double layer and by pseudocapacitive ion storage on the surface of the material. It is established that based on NCM, electrochemical capacitors are stable in all range of current density and material capacity essentially depends on appropriate choice of electrolyte.

Electrical properties of composites based on nanoporous carbon material

“…Vtotal, cm 3 The impedance spectra for both systems (Fig. 1) have a typical form of capacitive accumulation of electric charge at the composite/electrolyte interface, as evidenced by the fact that at low frequencies the angle of inclination of the diagrams tends to 90º.…”

“…Therefore, one of the most promising directions of research in electrochemical charge storage systems is the investigation of the physical and chemical processes as well as electrical properties of ECs electrode materials. It is advisable to use the method of impedance spectroscopy (IS) to investigate the electrochemical electrode/electrolyte interaction, determining the voltage at which charge transfer occurs in this system, as well as the value of the accumulated charge and the electrical resistance of the system [3]. Based on nanoporous carbon material, which is chemically resistant to most electrolytes, the IS method can determine the dependence of the specific capacity of the system on the applied potential and the potential region in which charge accumulation occurs due to of DEL formation.…”

Mechanisms of charge accumulation of the electrochemical system LaMnO3 / AC

“…It is should be noted that carbon materials are considered the best materials for the EC. Moreover, carbon materials are inexpensive, easy to obtain, have high specific energy-intensive characteristics, chemically and electrochemically stable [27]. A significant improvement in the electrochemical parameters of such systems can be achieved due to combining carbon materials with other compounds, such as spinels [28] or manganese oxide [29].…”

Electrochemical Properties of the Nanoporous Carbon/Aprotic Electrolyte System

“…Nanoporous carbon (NC) often used as such electrode material due to chemically stability to different electrolytes and high specific surface area (~ 2000 m 2 /g) [1]. The key factors determining the performances of electrochemical capacitors are properties of electrolyte [2,3]. In theory the high value of specific capacity depends on the high values of specific surface area.…”