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@INPROCEEDINGS{Raijmakers:1053939,
author = {Raijmakers, Luc and Ali, Haider Adel and Tempel, Hermann
and Notten, Peter H. L. and Eichel, Rüdiger-A.},
title = {{I}mproving the accuracy of physics-based battery model
simulations: {D}etermination of solid-phase diffusion
coefficients and reaction-rate constants},
reportid = {FZJ-2026-01616},
year = {2025},
abstract = {Physics-based models are important tools for simulating and
optimizing the performance of Li-ion batteries, with the
Doyle-Fuller-Newman (DFN) model being the most widely
adopted [1]. However, the accuracy of this model depends
heavily on its parameters. Two of the most critical
parameters for the model are the solid-phase diffusion
coefficient $(D_s)$ and the reaction-rate coefficient
$(k_0)$ [2]. These parameters are critical because $D_s$
controls the diffusion overpotential, while $k_0$ governs
the charge-transfer overpotential. Together, these two
overpotentials account for more than half of the total
overpotential in a battery. Therefore, precise determination
of $D_s$ and $k_0$ will enhance battery state-estimation,
improve fast-charging protocols, and provide deeper insights
into battery degradation mechanisms, leading to more
efficient and reliable Li-ion battery applications.Since
$D_s$ and $k_0$ cannot be directly measured, they must be
estimated – a process that can be quite complex. A review
of the literature reveals that many studies have
inaccurately determined these parameters. In this work, we
have re-evaluated the estimation methods to address these
inaccuracies and improve the reliability of the estimation
process. This work uses galvanostatic and potentiostatic
intermittent titration techniques (GITT and PITT,
respectively) to estimate these key parameters using
half-cells with Li(Ni0.4Co0.6)O2 electrodes. The two
compared estimation methods are the widely used analytical
approach based on Weppner and Huggins's work [3] and a
physics-based approach with the DFN model.Figure 1 shows DFN
model simulation results under dynamic current-loading
conditions with $D_s$ and $k_0$ determined from various
measurement and estimation techniques. The combination of
GITT measurements with a newly proposed physics-based
protocol for determining $D_s$ and $k_0$ gives the highest
simulation accuracy, achieving an average root mean square
error (RMSE) of 5.5 mV, as shown in Figure 1a. In contrast,
the analytical method in combination with GITT measurements
for determining $D_s$ and $k_0,$ which is the most used in
literature, shows the least accuracy, with an RMSE of 24.2
mV, as shown in Figure 1b. This higher error is attributed
to the limitations inherent in the analytical approach's
core assumptions.This study introduces a novel protocol for
optimizing $D_s$ and $k_0$ as a function of lithiation
degree from a single measurement, eliminating the need for
expensive and complex techniques such as electrochemical
impedance spectroscopy (EIS).References:[1] M. Doyle, T.F.
Fuller, J. Newman, Modeling of Galvanostatic Charge and
Discharge of the Lithium/Polymer/Insertion Cell, J.
Electrochem. Soc. 140 (1993) 1526.
https://doi.org/10.1149/1.2221597.[2] H.A.A. Ali, L.H.J.
Raijmakers, K. Chayambuka, D.L. Danilov, P.H.L. Notten,
R.-A. Eichel, A comparison between physics-based Li-ion
battery models, Electrochimica Acta (2024) 144360.
https://doi.org/10.1016/j.electacta.2024.144360.[3] W.
Weppner, R.A. Huggins, Determination of the Kinetic
Parameters of Mixed‐Conducting Electrodes and Application
to the System Li3Sb, J. Electrochem. Soc. 124 (1977) 1569.
https://doi.org/10.1149/1.2133112.},
month = {Apr},
date = {2025-04-02},
organization = {Advanced Battery Power Conference,
Aachen (Germany), 2 Apr 2025 - 3 Apr
2025},
subtyp = {After Call},
cin = {IET-1},
cid = {I:(DE-Juel1)IET-1-20110218},
pnm = {1223 - Batteries in Application (POF4-122)},
pid = {G:(DE-HGF)POF4-1223},
typ = {PUB:(DE-HGF)24},
url = {https://juser.fz-juelich.de/record/1053939},
}