Optimize Supercapacitor Performance: A Comprehensive Guide to Electrochemical Testing and Design

This article explores the electrochemical performance of symmetric supercapacitors (SCs) constructed using CuO/NiO as both the anode and cathode materials. The supercapacitors are designed with a PVA/KOH gel electrolyte and Whatman cellulose filter paper as a diaphragm.

Electrochemical characterization was conducted using a CHI 660E electrochemical workstation (Zhenhua, Shanghai, China). Cyclic voltammetry (CV) tests were performed within a voltage window of 0 to 0.9 V. Electrostatic charge/discharge (GCD) tests were carried out at current densities ranging from 1 mA/cm2 to 3.5 mA/cm2. Impedance spectroscopy (EIS) analyses were also performed to further understand the electrochemical behavior.

The PVA/KOH gel electrolyte was prepared by dissolving 3 g of PVA in 25 mL of DI water and stirring at 60 ﾰC for 30 minutes. Subsequently, 1.5 g of KOH and 5 mL of DI water were added to the solution and stirred for 20 minutes.

The areal specific capacitance (CA), measured in mF/cm2, was calculated from the GCD curves using Equation (1). The energy density (EA) and power density (PA) were computed using Equations (2) and (3) based on the GCDs.

The electrochemical performance of the device was studied in all-solid symmetric supercapacitors. The energy density (E) and power density (P) of the corresponding supercapacitors (SSCs) were calculated using the following equations:

[Equation (1)][Equation (2)][Equation (3)]

This comprehensive approach to electrochemical testing and analysis provides valuable insights into the performance of the CuO/NiO//CuO/NiO symmetric supercapacitors, paving the way for future advancements in energy storage technologies.