Percolation Characteristics of Conductive Additives for Capacitive Flowable (Semi-Solid) Electrodes

Understanding the percolation characteristics of multi-component conducting suspensions is critical for the development of flowable (semi-solid) electrochemical systems for energy storage and capacitive deionization with optimal electrochemical and rheological performance. Despite its significance, not much is known about the impact of the selected particle morphology on the agglomeration kinetics and the state of dispersion in flowable electrodes. In this study, impact of the conductive additive morphology on the electrochemical and rheological response of capacitive flowable electrodes has been systematically investigated. Critical viscosity limits have been determined for common carbon additives that offer slurry formulations with improved electrochemical and rheological performance. For instance, at the same electrical conductivity of 60 mS cm-1, higher aspect ratio particles, such as graphene and carbon nanotubes, offered 4- and 2.4-times lower viscosity compared to carbon black due to the improved p...