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Contribution à l'étude du vieillissement de supercondensateurs à électrolyte organique à base de carbones activés

Abstract : The energy which is stored in electrochemical capacitors is proportional to the square of voltage. Consequently, the most attractive supercapacitors are those which operate in organic electrolyte medium, with an electrolyte potential window which theoretically can easily reach more than 3 V. However, even using lower values of voltage, there is a remarkable fading of the electrochemical characteristics with operating time, that is mainly characterized by capacitance loss and resistance increase. This work was understand ageing mechanisms of supercapacitor using activated carbon electrode with TEABF4 1M in acetonitrile as electrolyte. An experimental device was conceived to analyse gases formed at various ageing time using characterizations such as mass spectrometry, Raman spectroscopy and FTIR. Moreover, electrochemical measurements carried out by complex impedance spectroscopy and modeling of the spectra obtained in terms of equivalent circuits, helped make assumptions about the degradation process. These have been validated by a study of various physicochemical parameters of internal components: (i) by gas adsorption (ii) by elementary chemical analysis, (iii) by thermal analysis and (iv) by nuclear magnetic resonance. Finally, a comparison with bibliographic data (patents) allowed to suggest and test other secondary factors that should be taken into account to improve the shelf life of these electrochemical devices.
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https://hal.univ-lorraine.fr/tel-01746326
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Submitted on : Thursday, March 29, 2018 - 10:31:13 AM
Last modification on : Thursday, February 25, 2021 - 11:04:56 AM

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  • HAL Id : tel-01746326, version 1

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Johann Lejosne. Contribution à l'étude du vieillissement de supercondensateurs à électrolyte organique à base de carbones activés. Autre. Université Henri Poincaré - Nancy 1, 2010. Français. ⟨NNT : 2010NAN10017⟩. ⟨tel-01746326⟩

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