Outstanding performance of activated graphene based supercapacitors in ionic liquid electrolyte from −50 to 80°C

Wan-Yu Tsai (1) , Rongying Lin (1) , Shanthi Murali (2) , Li Li Zhang (2) , John K. Mcdonough (3) , Rodney S. Ruoff (2) , Pierre-Louis Taberna (1) , Yury Gogotsi (3) , Patrice Simon (1, 4)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 University of Texas at Austin [Austin]
3 Drexel University
4 RS2E - Réseau sur le stockage électrochimique de l'énergie

High specific surface area (SSA ∼2000 m2/g) porous KOH-activated microwave exfoliated graphite oxide (‘a-MEGO’) electrodes have been tested in a eutectic mixture of ionic liquids (1:1 by weight or molar ratio N-methyl-N-propylpiperidinium bis(fluorosulfonyl)imide (PIP13-FSI) and N-butyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (PYR14-FSI)) as electrolyte for supercapacitor applications. By optimizing the carbon/electrolyte system, outstanding capacitive performance has been achieved with high capacitance (up to 180 F/g) and wide electrochemical window (up to 3.5 V) over a wide temperature range from −50 °C to 80 °C. This is the first demonstration of a carbon–ionic liquid system capable of delivering capacitance in excess of 100 F/g below room temperature. The excellent electrochemical response of the proposed couple shows that optimization of the carbon/electrolyte interface is of great importance for improving capacitive energy storage.

Mots clés: Electrochemical capacitors; Activated graphene; Ionic liquid mixture; Wide temperature range

Domaines: Matériaux; Matériaux

Wan-Yu Tsai, Rongying Lin, Shanthi Murali, Li Li Zhang, John K. Mcdonough, et al.. Outstanding performance of activated graphene based supercapacitors in ionic liquid electrolyte from −50 to 80°C. Nano Energy, 2013, vol. 2 (n° 3), pp. 403-411. ⟨10.1016/j.nanoen.2012.11.006⟩. ⟨hal-01154261⟩