Lindberg, S., Jeschke, S., Jankowski, P., Abdelhamid, M., Brousse, T., Le Bideau, J., Johansson, P. & Matic, A. (2020) Charge storage mechanism of alpha-MnO2 in protic and aprotic ionic liquid electrolytes. Journal of Power Sources, 460 228111.
Added by: Richard Baschera (2020-05-15 08:26:42) Last edited by: Richard Baschera (2020-05-15 08:30:06)
|Type de référence: Article
Numéro d'identification (ISBN etc.): 0378-7753
Clé BibTeX: Lindberg2020
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|Catégories: INTERNATIONAL, PMN, ST2E
Mots-clés: hybrid, ionic liquid, mno2, Protic, Supercapacitor
Créateurs: Abdelhamid, Brousse, Jankowski, Jeschke, Johansson, Le Bideau, Lindberg, Matic
Collection: Journal of Power Sources
Consultations : 7/158
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|Liens URLs http://www.science ... /S0378775320304146|
In this work we have investigated the charge storage mechanism of MnO2 electrodes in ionic liquid electrolytes. We show that by using an ionic liquid with a cation that has the ability to form hydrogen bonds with the active material (MnO2) on the surface of the electrode, a clear faradaic contribution is obtained. This situation is found for ionic liquids with cations that have a low pKa, i.e. protic ionic liquids. For a protic ionic liquid, the specific capacity at low scan rate rates can be explained by a densely packed layer of cations that are in a standing geometry, with a proton directly interacting through a hydrogen bond with the surface of the active material in the electrode. In contrast, for aprotic ionic liquids there is no interaction and only a double layer contribution to the charge storage is observed. However, by adding an alkali salt to the aprotic ionic liquid, a faradaic contribution is obtained from the insertion of Li+ into the surface of the MnO2 electrode. No effect can be observed when Li+ is added to the protic IL, suggesting that a densely packed cation layer in this case prevent Li-ions from reaching the active material surface.