Replacing electrochemical measurement by colorimetric measurement to evaluate supercapacitor electrodes

Abstract

The traditional electrochemical measurement is the standard method to characterize the electrochemical performance of supercapacitor (SC) electrodes. In this work, we demonstrate that the colorimetric measurement can not only partially replace the electrochemical measurement to characterize the electrochemical performance, but also supplement the gaps for detecting the health of SC electrodes. First, we establish a relationship of color values with the electrochemical performances of SC electrodes, using galvanostatic charge–discharge tests, cyclic voltammetry tests, rate capability tests, and cycle stability analysis. Second, colorimetric measurement also offers unique advantages over electrochemical measurement, such as identifying normal/degraded/failed regions of the electrode and accurately responding to changes in temperature-dependent behavior. Therefore, this work proves that colorimetric measurement effectively complements and partially replaces electrochemical measurement, providing an alternative for a more thorough and accurate understanding of the intrinsic characteristics and dynamic evolution of SC electrodes.