Lithium-ion battery cells are used in numerous applications, and their dynamic behaviour
can be described using equivalent circuit models. This thesis investigates the
characterization of a Samsung INR18650-25R battery cell and the parameterization of
a two-RC equivalent circuit model. A pulse measurement protocol was used to measure
the voltage response of the cell at different states of charge. The model parameters were
determined using differential evolution with global and local parameterization approaches.
In the global parameterization, a single set of five parameters was determined
for all 20 measurement segments, whereas in the local parameterization, a separate
parameter set was determined for each segment. The global parameterization achieved
an average RMSD of 0.915 mV, while the local parameterization achieved 0.378 mV.
The local approach therefore reduced the average RMSD by approximately 59 % and
provided a better fit to the measured response at all considered states of charge.
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