Development of a Capacitance versus Voltage Model for Lithium-Ion Capacitors
| Autor: | Ali Sari, Nagham El Ghossein, Pascal Venet |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Differential capacitance capacitance evolution Double-layer capacitance Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology Capacitance lithium-ion capacitor law.invention law Lithium-ion capacitor lcsh:TK1001-1841 0202 electrical engineering electronic engineering information engineering Electrochemistry Electrical and Electronic Engineering C(V) curve Condensed matter physics 020208 electrical & electronic engineering stern model differential capacitance aging mechanisms performance degradation lifetime analysis 021001 nanoscience & nanotechnology lcsh:Production of electric energy or power. Powerplants. Central stations Capacitor chemistry lcsh:Industrial electrochemistry Electrode Lithium 0210 nano-technology Voltage lcsh:TP250-261 |
| Zdroj: | Batteries, Vol 6, Iss 54, p 54 (2020) Batteries; Volume 6; Issue 4; Pages: 54 |
| ISSN: | 2313-0105 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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