Effects of concentration and temperature of EMIMBF4/acetonitrile electrolyte on the supercapacitive behavior of graphene nanosheets
- 28 March 2012
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of Materials Chemistry
- Vol. 22 (18), 8853-8861
- https://doi.org/10.1039/c2jm15537k
Abstract
Graphene nanosheets (GNSs)–ionic liquids (ILs) electrochemical system is of great interest as it shows excellent electrochemical properties for high performance supercapacitors. In this paper, the effects of concentration and temperature of ILs electrolyte on the electrochemical properties of a GNSs electrode are characterized by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy measurements (EIS) in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4)/acetonitrile electrolyte. The results show that the internal resistance and the specific capacitance are strongly dependent on the variation of molar concentration of EMIMBF4, and the GNSs electrode exhibits high specific capacitance (128.2 F g−1) and a wide potential window (2.3 V) in 2.0 M EMIMBF4/acetonitrile electrolyte, indicating the excellent electrochemical performance. Moreover, the GNSs electrode has wide operating temperatures ranging from −20 °C to 60 °C with a potential window from −0.6 V to 1.5 V in the EMIMBF4/acetonitrile electrolyte. The result also reveals a weak dependence of the supercapacitive performance of the GNSs electrode on the temperature of the EMIMBF4/acetonitrile electrolyte. In addition, the specific capacitances have almost no decay after 1500 charge/discharge cycles in the above mentioned temperature region, demonstrating the good stability of the GNSs–ILs system in high-temperature and low-temperature environments.Keywords
This publication has 58 references indexed in Scilit:
- Graphene based new energy materialsEnergy & Environmental Science, 2011
- Facile synthesis of large-area manganese oxide nanorod arrays as a high-performance electrochemical supercapacitorEnergy & Environmental Science, 2011
- Best practice methods for determining an electrode material's performance for ultracapacitorsEnergy & Environmental Science, 2010
- A Cost‐Effective Supercapacitor Material of Ultrahigh Specific Capacitances: Spinel Nickel Cobaltite Aerogels from an Epoxide‐Driven Sol–Gel ProcessAdvanced Materials, 2010
- Rapid, Facile Microwave-Solvothermal Synthesis of Graphene Nanosheets and Their Polyaniline Nanocomposites for Energy StrorageChemistry of Materials, 2009
- Mesoporous Hydrous Manganese Dioxide Nanowall Arrays with Large Lithium Ion Energy Storage CapacitiesAdvanced Functional Materials, 2009
- Neutrophil Soldiers or Trojan Horses?Science, 2008
- Graphene-based composite materialsNature, 2006
- The Bourner lecture: Power sources and the new energy economyJournal of Power Sources, 2004
- Electrochemical capacitor performance of hydrous ruthenium oxide/mesoporous carbon composite electrodesJournal of Power Sources, 2003