Yielding behavior of concentrated lithium-ion battery anode slurry

The nonlinear rheology of a concentrated lithium-ion battery anode slurry was examined under large amplitude oscillatory shear and interpreted with a sequence of physical process (SPP) analysis. A complex interplay of three anode slurry components—graphite (Gr) as an active material, carbon black (CB) as a conductive additive, and carboxymethyl cellulose (CMC) as a binder—leads to a two-step yielding behavior, represented as the secondary plateau in dynamic strain and stress sweep tests. We demonstrate that a two-step yielding behavior is manifested as double deltoids in SPP analysis through the study of intra-cycle rheological transition under oscillatory shear flow. Slurries of Gr-CMC exhibit the two-step yielding behavior; slurries of CB-CMC do not, suggesting that Gr and CMC are the primary causes of two-step yielding in an anode slurry. A sedimentation test on a dilute Gr-CMC soluti…