Comprehensive potentiodynamic analysis of electrodes performance in hybrid capacitors
[ 1 ] Wydział Technologii Chemicznej, Politechnika Poznańska | [ 2 ] Instytut Chemii i Elektrochemii Technicznej, Wydział Technologii Chemicznej, Politechnika Poznańska | [ SzD ] doctoral school student | [ P ] employee
2023
scientific article
english
- Potentiodynamic analysis
- Li-ion capacitor
- Electrodes contribution
- Scan rate determination
EN A methodology which assesses the potentiodynamic characteristics of individual electrodes in hybrid capacitors (HCs) is introduced, using a Li-ion capacitor (LIC) as an example. Each electrode contribution was calculated from cyclic voltammetry (CV) measurements on a cell equipped with a reference electrode by adapting the procedure for electrical double-layer capacitors. It has been confirmed that, during the potentiodynamic analysis of a hybrid capacitor, the scan rate of the electrodes (dE+/dt and dE-/dt) is not constant in time. Furthermore, dE-/dt tends to 0, while dE+/dt aims to reach the rate of the voltage sweep (dU/dt). By contrast, when the electrodes are analyzed separately at a constant potential scan rate, the voltammogram of the battery-type negative electrode does not provide the same current response as a hybrid capacitor, where only the voltage ramp is controlled. The proposed methodology is fundamental for revealing any imbalance in the contributions of the electrodes and providing a correct representation of their current profiles during the potentiodynamic analysis of a hybrid cell.
13.01.2023
107436-1 - 107436-6
Article number: 107436
CC BY-NC-ND (attribution - noncommercial - no derivatives)
open journal
final published version
13.01.2023
at the time of publication
public
100
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