Modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications
Diagnosis of ageing mechanisms in supercapacitors is made difficult by the enforcement of various ageing factors in the current ageing tests. The thesis presents the exact determination of the ageing mechanism by separating the impacts of high temperature, current cycling and constant voltage applic...
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| Format: | Thesis (University of Nottingham only) |
| Language: | English |
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2015
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| Online Access: | https://eprints.nottingham.ac.uk/29169/ |
| _version_ | 1848793728433520640 |
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| author | Mohammad Naim, Nur Nafisah |
| author_facet | Mohammad Naim, Nur Nafisah |
| author_sort | Mohammad Naim, Nur Nafisah |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Diagnosis of ageing mechanisms in supercapacitors is made difficult by the enforcement of various ageing factors in the current ageing tests. The thesis presents the exact determination of the ageing mechanism by separating the impacts of high temperature, current cycling and constant voltage applications in accelerated ageing tests. The state of health (SOH) of the supercapacitors are monitored periodically with electrochemical impedance spectroscopy, cyclic voltammetry and constant current test to observe the evolution of ageing.
The thesis identifies patterns of ageing from the changes at supercapacitor impedance. The thesis also presents the cause of the increase in ESR and the loss of capacitance in supercapacitors. High temperature application causes the appearance of high frequency semicircle which reflects the damage at the electrode-current collector interface. A tilt of the impedance line at low frequencies reflects modifications of electrodes and it is most sensitive to current cycling and constant voltage applications. The increase in ESR is observed to be caused by a single ageing mechanism while the capacitance loss is caused by multiple interactions of these ageing mechanisms at the same time.
The thesis develops a supercapacitor model by means of electrical equivalent circuit. The model is divided into two parts based on the changes in its SOH: the baseline model represents the early stage of the supercapacitor life and the ageing model represents the phase of ageing. The models show dynamic interactions between ageing process and supercapacitor electrical performance. The supercapacitor model, in the form of fractional-order model, reduces the number of circuit components and shows excellent electrical behaviour particularly at the open circuit voltage decay and voltage recovery period. The parameterisation of model parameters shows that aged supercapacitors experience an increase of distributed resistance in the electrode pores and an increase of diffusion impedance at high temperature. |
| first_indexed | 2025-11-14T19:04:55Z |
| format | Thesis (University of Nottingham only) |
| id | nottingham-29169 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T19:04:55Z |
| publishDate | 2015 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-291692025-02-28T11:35:41Z https://eprints.nottingham.ac.uk/29169/ Modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications Mohammad Naim, Nur Nafisah Diagnosis of ageing mechanisms in supercapacitors is made difficult by the enforcement of various ageing factors in the current ageing tests. The thesis presents the exact determination of the ageing mechanism by separating the impacts of high temperature, current cycling and constant voltage applications in accelerated ageing tests. The state of health (SOH) of the supercapacitors are monitored periodically with electrochemical impedance spectroscopy, cyclic voltammetry and constant current test to observe the evolution of ageing. The thesis identifies patterns of ageing from the changes at supercapacitor impedance. The thesis also presents the cause of the increase in ESR and the loss of capacitance in supercapacitors. High temperature application causes the appearance of high frequency semicircle which reflects the damage at the electrode-current collector interface. A tilt of the impedance line at low frequencies reflects modifications of electrodes and it is most sensitive to current cycling and constant voltage applications. The increase in ESR is observed to be caused by a single ageing mechanism while the capacitance loss is caused by multiple interactions of these ageing mechanisms at the same time. The thesis develops a supercapacitor model by means of electrical equivalent circuit. The model is divided into two parts based on the changes in its SOH: the baseline model represents the early stage of the supercapacitor life and the ageing model represents the phase of ageing. The models show dynamic interactions between ageing process and supercapacitor electrical performance. The supercapacitor model, in the form of fractional-order model, reduces the number of circuit components and shows excellent electrical behaviour particularly at the open circuit voltage decay and voltage recovery period. The parameterisation of model parameters shows that aged supercapacitors experience an increase of distributed resistance in the electrode pores and an increase of diffusion impedance at high temperature. 2015-07-25 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/29169/1/Nafisah%20Thesis%2008591_final.pdf Mohammad Naim, Nur Nafisah (2015) Modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications. PhD thesis, University of Nottingham. supercapacitors; ageing; ageing mechanism; electrochemical impedance spectroscopy; ageing model; equivalent circuit; accelerated ageing test; fractional-order; constant phase element |
| spellingShingle | supercapacitors; ageing; ageing mechanism; electrochemical impedance spectroscopy; ageing model; equivalent circuit; accelerated ageing test; fractional-order; constant phase element Mohammad Naim, Nur Nafisah Modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications |
| title | Modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications |
| title_full | Modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications |
| title_fullStr | Modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications |
| title_full_unstemmed | Modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications |
| title_short | Modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications |
| title_sort | modelling the ageing behaviour of supercapacitors using electrochemical impedance spectroscopy for dynamic applications |
| topic | supercapacitors; ageing; ageing mechanism; electrochemical impedance spectroscopy; ageing model; equivalent circuit; accelerated ageing test; fractional-order; constant phase element |
| url | https://eprints.nottingham.ac.uk/29169/ |