Controlling of Dispersion State of Particles in Slurry and Electrochemical Properties of Electrodes

Abstract

This paper presents the correlation between the difference of the dispersion state of particles such as LiCoO2 and acetylene black in the slurries and the electrochemical behavior. Three different preparation processes were applied to achieve the different dispersion state of particles in slurries, and thus obtained slurries are characterized by rheological measurement. It is found that dispersion process with highly loaded slurry or under high shear flow reduces elastic moduli and that their combination achieved the most dispersed state of the particles among the slurries investigated. X-ray computed tomography unveiled that the electrodes manufactured from these slurries contain the aggregates and the size of aggregates in the electrodes was reduced with the decrease in elastic moduli of slurry. At the discharge current density of 10 mA g−1, these electrodes exhibited 140 mAh g−1 of discharge capacities. At 1000 mA g−1, the electrode prepared from highly loaded slurry maintained 80% of the capacity that obtained at the current density of 10 mA g−1. The capacity of the electrode prepared from the slurry under highly loaded and high shear flow, on the other hand, dropped below 10%, indicated that the electrode from the most dispersed slurry has the worst rate performance.