Paper Number
RS10                         My Program 

Session
Real-World Rheology & Sustainability

Title
The roles of active materials and poly(vinylidene difluoride) in the shear rheology of lithium-ion battery slurry

Presentation Date and Time
October 14, 2024 (Monday) 2:10

Track / Room
Track 7 / Room 502

Authors (Click on name to view author profile)

  1. Liu, Qingsong (Northwestern University, Chemical ang biological engineering)
  2. Gupta, Yoshita (Northwestern University, Chemical and biological engineering)
  3. Richards, Jeffrey J. (Northwestern University, Chemical and Biological Engineering)

Author and Affiliation Lines (in printed abstract book)
Qingsong Liu, Yoshita Gupta and Jeffrey J. Richards
Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208

Speaker / Presenter 
Liu, Qingsong

Keywords
colloids; non-Newtonian fluids; real-world rheology; suspensions; sustainability

Text of Abstract
Lithium-ion batteries utilize porous cathodes which are a composite of micron-sized electrochemically AM (active material) particles, nanometer-scale conductive additive CB (carbon black), and polymer binder PVDF (poly(vinylidene difluoride)). To manufacture the cathodes, solid components are suspended in an organic solvent NMP (N-methyl-2-pyrrolidone), and the resulting suspension, or slurry, is nonequilibrium because of the attractive force between colloidal CB aggregates. Quantifying the shear rheology of LIB slurry is therefore critical to engineering the formulation and coating parameters for manufacturing high-quality cathodes. In this talk, we report the use of rheology to reveal the roles of AM and PVDF in the shear rheology of LIB slurry. We show that while the addition of both PVDF and AM to CB suspensions leads to enhanced breakup of CB agglomerates, the mechanisms remain different. Moreover, contrary to the prevalent assumptions of the PVDF role, we show that when PVDF is added to AM/CB suspensions, the enhanced CB breakup induced by AM particles is mediated by PVDF. Our results reveal the nontrivial roles of all solid components in determining the shear rheology of slurry that is critical to LIB cathode manufacturing.