Applicability of Modified Cox-Merz Rule to Concentrated Suspensions

Abstract

The present work studied the rheological properties of concentrated non-colloidal aqueous suspensions of graphite particles together with carboxymethyl cellulose (CMC) having various molecular weights, especially focusing on the applicability of the modified Cox-Merz rule. These suspensions were investigated as model slurries to produce anode electrodes of lithium ion batteries. In the case of suspensions containing high molecular weight CMC, the complex viscosity resulting from the measurements of frequency dependence of the viscoelastic moduli at high strain values was in good agreement with the steady state viscosity. That is, the data conformed to the modified Cox-Merz rule. However, the data obtained from suspensions containing low molecular weight CMC did not agree with the modified Cox-Merz rule. The difference in the applicability of this model is considered to be attributed to variations in the ability of the suspensions to recover to a stable state during the application of cyclic strain.