TY - JOUR
T1 - Computational modeling of particle hydrodynamics and charging process for the flowable electrodes of carbon slurry
AU - Karzar-Jeddi, Mehdi
AU - Luo, Haoxiang
AU - Cummings, Peter T.
AU - Hatzell, Kelsey B.
N1 - Funding Information:
This work was supported by the Discovery grant from the Vanderbilt University, an NSF grant (CBET-1706956), and also the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.
Publisher Copyright:
© 2019 The Electrochemical Society.
PY - 2019
Y1 - 2019
N2 - Slurry of activated carbon particles mixed with an aqueous electrolyte solution has been used as "flowable electrode" in a few recent electrochemical systems, e.g., electrochemical flow capacitors (EFCs) for energy storage, and flow-electrode capacitive deionization (FCDI) for water treatment. In these applications, the porous carbon particles with very large specific surface area adsorb ions from the electrolyte and meanwhile store electrical charges when a voltage source is added in the charging process. Under the flow condition, the motion of the particles and their mutual contact form a dynamically varying electrical network for the charge transport through the bulk material. We introduce a novel particle-based computational model using the Stokesian dynamics to simulate the hydrodynamic interaction of the carbon particles and the charge transport. An analogous electrical circuit model is developed by approximating the particles with many interconnected resistor-capacitor units, and the circuit's topology is temporally changing depending on the instantaneous particle configuration. The Stokesian model and the circuit model are solved simultaneously to study how the hydrodynamic interaction and cluster formation affect the charge transport process of the slurry. The presence of the stationary current collector can be included to incorporate the near-wall effects on particle mobility. In the simulation, we vary the particle concentration as well as the ratio of the particle charging time to the hydrodynamic interaction time. The results shows that the charge transport in the carbon slurry is enhanced by increasing the concentration of the particles and faster particle charging. In addition, cluster formation of the particles plays an important role for the electronic transport process. After scaling, the transient electrical current from the present study generally agrees with that from previous experimental and modeling studies.
AB - Slurry of activated carbon particles mixed with an aqueous electrolyte solution has been used as "flowable electrode" in a few recent electrochemical systems, e.g., electrochemical flow capacitors (EFCs) for energy storage, and flow-electrode capacitive deionization (FCDI) for water treatment. In these applications, the porous carbon particles with very large specific surface area adsorb ions from the electrolyte and meanwhile store electrical charges when a voltage source is added in the charging process. Under the flow condition, the motion of the particles and their mutual contact form a dynamically varying electrical network for the charge transport through the bulk material. We introduce a novel particle-based computational model using the Stokesian dynamics to simulate the hydrodynamic interaction of the carbon particles and the charge transport. An analogous electrical circuit model is developed by approximating the particles with many interconnected resistor-capacitor units, and the circuit's topology is temporally changing depending on the instantaneous particle configuration. The Stokesian model and the circuit model are solved simultaneously to study how the hydrodynamic interaction and cluster formation affect the charge transport process of the slurry. The presence of the stationary current collector can be included to incorporate the near-wall effects on particle mobility. In the simulation, we vary the particle concentration as well as the ratio of the particle charging time to the hydrodynamic interaction time. The results shows that the charge transport in the carbon slurry is enhanced by increasing the concentration of the particles and faster particle charging. In addition, cluster formation of the particles plays an important role for the electronic transport process. After scaling, the transient electrical current from the present study generally agrees with that from previous experimental and modeling studies.
UR - http://www.scopus.com/inward/record.url?scp=85073626093&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85073626093&partnerID=8YFLogxK
U2 - 10.1149/2.1191912jes
DO - 10.1149/2.1191912jes
M3 - Article
AN - SCOPUS:85073626093
SN - 0013-4651
VL - 166
SP - A2643-A2653
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 12
ER -