Effects of particle dispersion and slurry preparation protocol on electrochemical performance of capacitive flowable electrodes

Abstract

In this study, the effects of dispersion time and mixing methodology on electrochemical performance of flowable carbon electrodes have been investigated. Specifically, 20 different cases have been tested by systematically changing the mixing time (1.5, 3, 4.5, 8, 15 min), the mixing methodology (stir-bar vs. high-speed shear mixing), and the electrode composition (activated carbon (AC) only and AC with multi-walled carbon nanotube slurries). Each case was subjected to direct current conductivity and cyclic voltammetry measurements to identify the contribution of studied parameters on the dispersion and electrochemical performance. Results indicate that up to 60% difference in conductivity can be observed by changing mixing time and methodology for the same electrode composition. Additionally, capacity differences up to 90% within the same slurry composition have been noticed by slightly changing the electrode preparation protocol. Such major discrepancy in electrochemical performance with minimal changes in the electrode preparation highlights the significance of the degree of particle dispersion in these systems and the necessity for establishing an optimal slurry preparation protocol to achieve the best performance for a selected composition and application. This study provides insights into potential effects of electrode preparation methods and degree of dispersion of active materials on the electrochemical performance of capacitive flowable electrodes.