Development of a Capacitance versus Voltage Model for Lithium-Ion Capacitors

The capacitance of Lithium-ion Capacitors (LiCs) highly depends on their terminal voltage. Previous research found that it varies in a nonlinear manner with respect to the voltage. However, none of them modeled the capacitance evolution while considering the physicochemical phenomena that happen in...

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Main Authors: Nagham El Ghossein, Ali Sari, Pascal Venet
Format: Article
Language:English
Published: MDPI AG 2020-11-01
Series:Batteries
Subjects:
Online Access:https://www.mdpi.com/2313-0105/6/4/54
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spelling doaj-ffec8e0ce71b478d869c49cce9f8fb2d2020-11-25T04:06:53ZengMDPI AGBatteries2313-01052020-11-016545410.3390/batteries6040054Development of a Capacitance versus Voltage Model for Lithium-Ion CapacitorsNagham El Ghossein0Ali Sari1Pascal Venet2Univ Lyon, University of Claude Bernard Lyon 1, Ecole Centrale de Lyon, INSA Lyon, CNRS, Ampère, F-69100 Villeurbanne, FranceUniv Lyon, University of Claude Bernard Lyon 1, Ecole Centrale de Lyon, INSA Lyon, CNRS, Ampère, F-69100 Villeurbanne, FranceUniv Lyon, University of Claude Bernard Lyon 1, Ecole Centrale de Lyon, INSA Lyon, CNRS, Ampère, F-69100 Villeurbanne, FranceThe capacitance of Lithium-ion Capacitors (LiCs) highly depends on their terminal voltage. Previous research found that it varies in a nonlinear manner with respect to the voltage. However, none of them modeled the capacitance evolution while considering the physicochemical phenomena that happen in a LiC cell. This paper focuses on developing a new capacitance model that is based on the Stern model of the electrochemical double layer capacitance. The model accounts for the asymmetric V-shape of the C(V) curve, which reflects the variation of the capacitance with respect to the voltage. The novelty of this study concerns the development of a model for LiCs that relies on the fundamental theory of Stern for the differential capacitance. The basic model of Stern is modified in order to account for the hybrid physicochemical structure of LiCs. Moreover, the model was applied to three aged cells to which accelerated calendar aging tests were applied at three voltage values: 2.2, 3 and 3.8 V. A drift of the voltage corresponding to the minimum capacitance was detected for the aged cells. This voltage is related to the neutral state of the positive electrode. The main cause of this phenomenon concerns the loss of lithium ions from the negative electrode of a LiC. In addition, capacitance values decreased after aging, showing an eventual blocking of the pores of the positive electrode. Therefore, the analysis of the C(V) curve was found to be an interesting tool for the interpretation of aging mechanisms.https://www.mdpi.com/2313-0105/6/4/54lithium-ion capacitorC(V) curvecapacitance evolutionstern modeldifferential capacitanceaging mechanisms
collection DOAJ
language English
format Article
sources DOAJ
author Nagham El Ghossein
Ali Sari
Pascal Venet
spellingShingle Nagham El Ghossein
Ali Sari
Pascal Venet
Development of a Capacitance versus Voltage Model for Lithium-Ion Capacitors
Batteries
lithium-ion capacitor
C(V) curve
capacitance evolution
stern model
differential capacitance
aging mechanisms
author_facet Nagham El Ghossein
Ali Sari
Pascal Venet
author_sort Nagham El Ghossein
title Development of a Capacitance versus Voltage Model for Lithium-Ion Capacitors
title_short Development of a Capacitance versus Voltage Model for Lithium-Ion Capacitors
title_full Development of a Capacitance versus Voltage Model for Lithium-Ion Capacitors
title_fullStr Development of a Capacitance versus Voltage Model for Lithium-Ion Capacitors
title_full_unstemmed Development of a Capacitance versus Voltage Model for Lithium-Ion Capacitors
title_sort development of a capacitance versus voltage model for lithium-ion capacitors
publisher MDPI AG
series Batteries
issn 2313-0105
publishDate 2020-11-01
description The capacitance of Lithium-ion Capacitors (LiCs) highly depends on their terminal voltage. Previous research found that it varies in a nonlinear manner with respect to the voltage. However, none of them modeled the capacitance evolution while considering the physicochemical phenomena that happen in a LiC cell. This paper focuses on developing a new capacitance model that is based on the Stern model of the electrochemical double layer capacitance. The model accounts for the asymmetric V-shape of the C(V) curve, which reflects the variation of the capacitance with respect to the voltage. The novelty of this study concerns the development of a model for LiCs that relies on the fundamental theory of Stern for the differential capacitance. The basic model of Stern is modified in order to account for the hybrid physicochemical structure of LiCs. Moreover, the model was applied to three aged cells to which accelerated calendar aging tests were applied at three voltage values: 2.2, 3 and 3.8 V. A drift of the voltage corresponding to the minimum capacitance was detected for the aged cells. This voltage is related to the neutral state of the positive electrode. The main cause of this phenomenon concerns the loss of lithium ions from the negative electrode of a LiC. In addition, capacitance values decreased after aging, showing an eventual blocking of the pores of the positive electrode. Therefore, the analysis of the C(V) curve was found to be an interesting tool for the interpretation of aging mechanisms.
topic lithium-ion capacitor
C(V) curve
capacitance evolution
stern model
differential capacitance
aging mechanisms
url https://www.mdpi.com/2313-0105/6/4/54
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AT alisari developmentofacapacitanceversusvoltagemodelforlithiumioncapacitors
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