D.C. voltammetry of ionic liquid-based capacitors: effects of Faradaic reactions, electrolyte resistance and voltage scan speed investigated using an electrode of carbon nanotubes in EMIM-EtSO4.
Carbon nanotube (CNT) electrodes in combination with ionic liquid (IL) electrolytes are potentially important for energy storage systems. We report electrochemical investigation of such a system involving a paper-electrode of multi-wall CNT (MWCNT) in the IL of 1-ethyl-3-methyl imidazolium ethylsulfate (EMIM-EtSO(4)). Our study concentrates on the analytical aspects of cyclic voltammetry (CV) to probe the double layer capacitance of these relatively unconventional systems (that involve rather large charge-discharge time constants). Both theoretical and experimental aspects of CV for such systems are discussed, focusing in particular, on the effects of Faradaic side-reactions, electrolyte resistance and voltage scan speeds. The results are analyzed using an electrode equivalent circuit (EEC) model, demonstrating a method to account for the typical artifacts expected in CV of CNT-IL interfaces.
Zheng
J P
JP
Department of Physics, Clarkson University, Clarkson Ave, Potsdam, NY 13699-5820, USA.
Pettit
C M
CM
Goonetilleke
P C
PC
Zenger
G M
GM
Roy
D
D
D025802:Electric Capacitance; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004573:Electrolytes; D052578:Ionic Liquids; D037742:Nanotubes, Carbon
D004573:Electrolytes; D052578:Ionic Liquids; D037742:Nanotubes, Carbon