Tech Briefs Magazine - February 2022 - BT-7

starting the project, but the group soon
found that it was taking a long time to
find the results they needed - and this
method was also more prone to errors.
When they later introduced the
LiveLink™ functionality into their
process, Chayambuka said, " it became so
much easier to generate results, and we
do not have to be behind a computer the
whole time. "
Cathodic current collector
Low flow rate
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SOC
Flow Rate, State-of-Charge,
and Energy Output
Through the results of the 2D model,
the researchers found that not all of the
SSFB's available charge is evenly exhausted.
In fact, the extent of each particle's discharge
depends on its position. The P3D
model showed the researchers how the
flow rate of the battery affects particle
discharge, an important factor for analyzing
the battery cells' dynamic behavior.
The team found that at high flow rates,
the cell voltage remains mostly stable. As
the discharge current increases, the voltage
difference between the initial and
steady-state voltage increases. For low
flow rates, the voltage differences between
the initial and steady-state stages
are more pronounced (Figure 5). By
understanding how flow rate affects the
dynamic behavior of cells, they can
design SSFBs for different flow rates and
predict the steady state for given sets of
initial conditions.
One of the most exciting aspects of
the project is that this is the first time
the flow-rate behavior of an SSFB has
been shown in a model. Further, experimental
SSFBs are showing similar transient
profiles to those found in COMSOL
Multiphysics®, demonstrating the validity
of the P3D model for this type of research.
Charging Up the Future of
Battery Research
Through the P3D model, the research
team demonstrated a novel way to model
SSFB behavior. With this model, they were
able to visualize the relationship between
hydrodynamic and electrochemical phenomena,
providing a new way to explore
the design of different types of batteries.
Next steps include introducing phase
change effects in the model materials,
introducing non-Newtonian behavior and
validating the simulated flow field with
Battery & Electrification Technology, February 2022
S5
Separator
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SOC
Z
y
X
Anodic current collector
Figure 3. Comparison of low-flow-rate and high-flow-rate SOC distributions in a P3D NiMH
SSFB model.
experiments using carbon-water suspensions
with the same rheological behavior
as the electrolytes.
" Our hope is to apply this model to
other types of flow batteries and test
other chemistries, which would be interesting, "
said Chayambuka. Further, " this
kind of model can be extrapolated to
other systems, because they use the
same principles, " said Dominguez. One
example she gives is the particle-based
system of wastewater treatment.
The group hopes that by continuing
their work, they will be able to realize an
experimental system to validate the
SSFB model, which would generate more
interest and funding so that they can
look into more ways of modeling energy
losses and optimized conditions. Improved
battery designs, and a better
understanding of how they work, can
improve how battery manufacturers store
energy and generate power.
This article was written by Brianne
Christopher of COMSOL, Inc., Burlington,
MA. For more information, visit 
.
COMSOL and COMSOL Multiphysics are
registered trademarks of COMSOL AB. MATLAB
is a registered trademark of The
MathWorks, Inc.
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High flow rate
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Tech Briefs Magazine - February 2022

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