Effect of impurities in different activated carbon materials and their in-depth electrochemical analysis in supercapacitor coin-cell devices with organic electrolyte

The trace levels of metallic and non-metallic impurities in activated carbon (AC) materials play a significant role in supercapacitor performance. However, the influence of these impurities on the electrochemical properties of supercapacitors has not been widely explored in the literature. In this work, we examined different activated carbon materials with different impurity levels for supercapacitor applications. The impurity content was analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES). The electrochemical performance of coin cells, including rate-capability, self-discharge, degradation, and burning behaviors, was studied in detail using various techniques, such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), electrochemical impedance spectroscopy (EIS), and floating tests. These electrochemical investigations provided valuable insights into the mechanisms by which impurities affect the electrochemical performance of supercapacitors. This study will be highly beneficial for the real-world fabrication of high-performance electrochemical supercapacitor devices for commercial applications.