Including double-layer capacitance in lithium-ion battery mathematical models

In this work we present a fundamental model‐based analysis of the effect of active material particle size distribution (PSD) on graphite electrodes and their performance. We focused on the determination of the impact of differently shaped and scaled PSDs on the electrode performance, which is mainly influenced by the performance of the individual particles and their interaction. A mathematical electrode model with a distributed particle size is used for analysis to identify the different local current densities and the charging behavior of the particles. The heterogeneity provokes uneven surface overpotentials and reaction rates. Their identification facilitates the investigation of the degradation of such heterogeneous systems. In addition, we present an approach that accounts for the change of a PSD because of the restructuring of the electrode morphology during battery usage into the mathematical model and identify the general impact of particle cracking and agglomeration on the battery performance. Moreover, the importance of PSD in Li‐ion batteries is shown by comparing the results obtained with a single particle model used commonly. This comparison shows that in case of narrow distributions surface‐area‐ and volume‐based mean approximations are sufficient to predict overpotentials and electrode capacity if kinetic losses are dominated either by reaction at the surface or diffusion processes, respectively. This work indicates that the PSD and its change impact the performance and degradation of Li‐ion batteries considerably. We suggest that the PSD and its evolution should be of particular interest in the study of the degradation of particle‐based electrodes.

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“…The charge balance is considered at the electrochemical double layer with [Eq. ]:

true a_{s} C^{DL} \frac{\partial E}{\partial t} = \overset{I}{true} - j^{Li}

…”

Section: Mathematical Modelmentioning

confidence: 99%

Simulating the Impact of Particle Size Distribution on the Performance of Graphite Electrodes in Lithium‐Ion Batteries

et al. 2016

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“…In batteries in general and LIBs specifically, this current is considered to be small relative to the total current [23]. -The faradaic current is due to the charge transfer reaction accompanied with Li-intercalation.…”

Section: Influence Of Electrode Densitymentioning

confidence: 99%

Influence of Electrode Density on the Performance of Li-Ion Batteries: Experimental and Simulation Results

et al. 2016

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Lithium-ion battery (LIB) technology further enabled the information revolution by powering smartphones and tablets, allowing these devices an unprecedented performance against reasonable cost. Currently, this battery technology is on the verge of carrying the revolution in road transport and energy storage of renewable energy. However, to fully succeed in the latter, a number of hurdles still need to be taken. Battery performance and lifetime constitute a bottleneck for electric vehicles as well as stationary electric energy storage systems to penetrate the market. Electrochemical battery models are one of the engineering tools which could be used to enhance their performance. These models can help us optimize the cell design and the battery management system. In this study, we evaluate the ability of the Porous Electrode Theory (PET) to predict the effect of changing positive electrode density in the overall performance of Li-ion battery cells. It can be concluded that Porous Electrode Theory (PET) is capable of predicting the difference in cell performance due to a changing positive electrode density.

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“…[1] Therefore, most research neglects all other degradation processes and focuses on the impact of the SEI. Based on this work, Gao et al [9] used a Point Defect Model (PDM) which has been introduced by Macdonald [10] to describe transport processes within the SEI. If processes with different time constants are affected by ageing, they can be revealed at their characteristic frequencies in the impedance spectrum.…”

Section: Introductionmentioning

confidence: 99%

Physico‐Chemical Modeling of a Lithium‐Ion Battery: An Ageing Study with Electrochemical Impedance Spectroscopy

Heinrich

Wolff

Harting

et al. 2019

Batteries & Supercaps

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Electrochemical Impedance Spectroscopy measurements and simulations are performed on a nickel manganese cobalt oxide (NMC)/graphite pouch cell. A physico-chemical continuum battery model is extended by a physical ageing model including a Solid Electrolyte Interphase. The model assumes a loss of electrochemically active surface area at anode and cathode as well as a growth of solid electrolyte interphase (SEI) layer thickness. These ageing parameters have been adjusted with an algorithm to achieve agreement between simulated and measured spectra. The results for a 28 mAh pouch cell show that the ageing model is suitable to correlate the change of the impedance spectrum with the degree of degradation of the cell. In detail, SEI thickness is shown to increase by 45 nm, while the anode and cathode loose 20 % and 57 % of their electrochemically active surface area, respectively. In addition, deviating measurement conditions and the end of life of the cell can be indicated by the parameter identification algorithm. Furthermore, it is demonstrated, that the change of the high and low frequency semicircles can be assigned to the anode SEI and cathode respectively.

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Including double-layer capacitance in lithium-ion battery mathematical models

Cited by 60 publications

References 15 publications

Simulating the Impact of Particle Size Distribution on the Performance of Graphite Electrodes in Lithium‐Ion Batteries

Simulating the Impact of Particle Size Distribution on the Performance of Graphite Electrodes in Lithium‐Ion Batteries

Influence of Electrode Density on the Performance of Li-Ion Batteries: Experimental and Simulation Results

Physico‐Chemical Modeling of a Lithium‐Ion Battery: An Ageing Study with Electrochemical Impedance Spectroscopy

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