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Cell optimisation of supercapacitors using a quasi-reference electrode and potentiostatic analysis.
- Source :
-
Journal of Power Sources . 6/1/2019, Vol. 424, p52-60. 9p. - Publication Year :
- 2019
-
Abstract
- A new criterion and potentiostatic method is demonstrated to determine the electrochemically stable potential window (ESPW) of supercapacitors, enabling the calculation of the optimal electrode mass ratio for two different electrode-electrolyte pairings. The criterion uses the decay of electrode current in a three-electrode test cell during potentiostatic ageing at progressively higher voltages to determine the ESPW. To perform these measurements a quasi-reference electrode (QRE) was incorporated within a CR2032 coin cell with a small and simple modification. This enabled three-electrode measurements to be performed inside the coin cell using organic electrolytes whilst outside a glovebox. The voltage-optimised mass ratio (m+/m−) for activated carbon electrodes in 1 M tetraethylammonium tetrafluoroborate (TEABF 4) in acetonitrile (ACN) and propylene carbonate (PC) electrolytes was shown to be 2.38 and 0.61 respectively. The validity of the technique was verified by full-cell potentiostatic ageing experiments on mass-balanced and mass-symmetric supercapacitors. For both electrolytes the maximum operating voltage, energy storage capacity and cycle lifetime were improved significantly with mass balancing. The maximum voltage increased from 2.0 V to 2.9 V for ACN and from 2.3 V to 2.7 V for PC, whilst the energy density increased by ∼90% for ACN and by ∼40% for PC. • Introduction of a reference electrode into a standard coin cell. • New criterion for determining stable voltage range. • Increases voltage to 2.9 V. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03787753
- Volume :
- 424
- Database :
- Academic Search Index
- Journal :
- Journal of Power Sources
- Publication Type :
- Academic Journal
- Accession number :
- 136153851
- Full Text :
- https://doi.org/10.1016/j.jpowsour.2019.03.062