Charge Storage Performance of Structurally Flexible Hybrid Ionic Liquid
Electrolyte in Supercapacitor
Abstract
The electrochemical and charge storage performance of a fluorine-free
structurally flexible pyrrolidinium-based ionic liquid hybrid
electrolyte (HILE) in a symmetric graphite-based supercapacitor is
thoroughly investigated. The HILE revealed thermal decomposition at 270
ºC, a glass transition (T g) temperature of −73 ºC, and
ionic conductivity of 0.16 mS cm −1 at 30 ºC. A
systematic variable temperature 1H and
31P NMR spectroscopy and diffusometry, cyclic
voltammetry (CV), electrochemical impedance spectroscopy (EIS), and
galvanostatic charge-discharge (GCD) are employed. HILE-based
supercapacitor demonstrated a notable specific capacitance of 186 Fg
−1 at a scan rate of 1 mVs −1 and a
specific capacitance of 122 Fg −1 at a current density
of 0.5 Ag −1. The maximum energy density of 49 Wh kg
−1, a power density of 370 W kg −1
at a current density of 0.5 A g −1 and a potential
window of 4V were obtained. HILE displayed a promising electrochemical
performance over a wide potential window of 4V and temperature range
(−20 ºC to 90 ºC) in a symmetric graphite supercapacitor.