Latex Migration in Battery Slurries during Drying

Abstract

We used real-time fluorescence microscopy to investigate the migration of latex particles in drying battery slurries. The time evolution of the fluorescence signals revealed that the migration of the latex particles was suppressed above the entanglement concentration of carboxymethyl cellulose (CMC), while it was significantly enhanced when CMC fully covered the surfaces of the graphite particles. In particular, a two-step migration was observed when the graphite particles flocculated by depletion attraction at high CMC/graphite mass ratios. The transient states of the nonadsorbing CMC and graphite particles in a medium were discussed, and the uses of this novel measurement technique to monitor the complex drying processes of films were demonstrated.

Delamination behavior of lithium-ion battery anodes: Influence of drying temperature during electrode processing

“…The influence of sedimentation, diffusion and evaporation rate is then estimated by a drying regime map based on calculations and experiments [31,32] or a comparison of Pe and s N to a value of 1 [30,33]. A different approach that estimates the possibility of a consolidation layer formation independently of the overall film height was applied here.…”

The effect of binders on the rheological properties and the microstructure formation of lithium-ion battery anode slurries

“…As mentioned in the section of graphite/SBR slurry, the gel structure is formed by hydrophobic attraction of graphite particles, and the graphite particles are dispersed by adsorbed SBR on the graphite surface. Like SBR, the CMC molecules tend to adsorb on the graphite surface, and the adsorption amount of CMC increases as the CMC concentration is increased [8,24]. Thus, both the viscosity and the moduli decrease as the CMC is added to the slurry until the concentration less than 0.28 wt%, meaning that the gel strength decreases due to the adsorbed CMC on the surface of the graphite.…”

“…A variety of microstructure in a particulate system can be formed due to the interaction between the particle and polymer such as bridging, depletion attraction or electrostatic repulsion [21e24]. The influence of the microstructure of the anode slurry on the latex migration during drying has also been reported [24]. The microstructure in the anode slurry was dependent on the ratio of CMC and graphite.…”

Improvement of Lithium‐Ion Battery Performance by Two‐Layered Slot–Die Coating Operation

“…However, high‐temperature drying may also cause surface defects, uneven distribution of particles, binder migrations, and other heterogeneous structure problems. All of these factors may affect the electrochemical performance of the composite LIBs …”