(574b) Effect of Ethanol on the Drying Rate and Rheological Properties of Lithium-Ion Battery Anode Slurries
AIChE Annual Meeting
2024
2024 AIChE Annual Meeting
Transport and Energy Processes
Poster Session: Transport and Energy Processes Division
Wednesday, October 30, 2024 - 3:30pm to 5:00pm
It is well-known that water is commonly used as a solvent in anode slurry manufacturing. In this study, we focused on the fact that the speed of the drying process can be improved by adding ethanol to water. Improved drying rates reduce energy consumption for solvent removal and improve the economics of anode production. The drying process is a multifaceted process involving not only heat transfer but also mass transfer from materials that make up the slurries, such as particles, binders, and solvents. Within this process, solvent evaporation, binder diffusion, and particle sedimentation occur.
Additionally, ethanol affects the microstructure of the anode slurry. Therefore, in this study, we not only measured the drying rate of the slurry containing ethanol as a solvent, but also investigated the rheological properties to determine the microstructure of the slurry.
To prepare the anode slurries, we used two types of graphite (spherical and flake shape) as active materials, carbon black as a conductive agent, and carboxymethyl cellulose (CMC) as a polymer binder. And we adjusted the water-to-ethanol ratio used as a solvent to 5:5, 6:4, 7:3, 8:2, 9:1, and 10:0.
First, the microstructure of the slurry was examined using an optical microscope (OM) to observe the dispersion of particles. Second, the drying rate of the slurry was measured at room temperature. Finally, steady shear tests and small amplitude oscillation shear (SAOS) tests were performed to investigate the thixotropy, rheological hysteresis properties, and linear viscoelasticity of the slurry, respectively.
This study allowed us to understand how the addition of ethanol as a solvent affects the microstructure, drying rate, and rheological properties of slurries with different active material types. Investigation of the effect of ethanol on anode slurries is important to improve the processability and economics of anode manufacturing.