Paper Number
SC52 

Session
Suspensions and Colloids

Title
Impact of surfactant chemistry on the structure and rheology of carbon black slurry used in all-iron flow batteries

Presentation Date and Time
October 12, 2022 (Wednesday) 5:05

Track / Room
Track 1 / Sheraton 4

Authors (Click on name to view author profile)

  1. Das, Mohan (Case Western Reserve University, Chemical and Biomolecular Engineering)
  2. Lee, KangJin (Case Western Reserve University, Chemical and Biomolecular Engineering)
  3. Wirth, Christopher L. (Case Western Reserve University, Chemical and Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Mohan Das, KangJin Lee and Christopher L. Wirth
Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, OH 44106

Speaker / Presenter 
Das, Mohan

Keywords
experimental methods; colloids; flow-induced instabilities; gels; microscopy; suspensions

Text of Abstract
Carbon black particles provide electrical percolation in the slurry-based electrodes used in all-iron redox flow batteries. However, the addition of carbon black particles leads to a multitude of rheological challenges as a result of strong interparticle interaction. Some of these challenges are increased slurry viscosity, flow instabilities, material accumulation in flow channels, loss of electrical percolation during flow, etc. Parameters such as particle dispersion, stability and yield stress of the slurry are critical for energy storage and efficient functioning of the flow battery. Altering interparticle interaction would greatly improve the above-mentioned parameters and help in achieving desired rheological and electrical properties for the slurry-based electrodes. We prepare a model slurry-based electrode by dispersing activated carbon black particles in 1 M sulfuric acid and vary their interparticle interaction by adding ionic and nonionic surfactants above critical micelle concentration (CMC). Using steady shear, oscillatory shear and time dependent rheological measurements, we study the viscoelastic response, shear thinning, aging and stability of the carbon black slurry in the presence of surfactants. Moreover, we examine the effect of surfactant addition on electrical percolation of the slurry by measuring electrical conductivity at rest and during flow. Finally, we investigate the effect of particle structuring during flow using high-speed particle image velocimetry (PIV).