Charge storage performance of a structurally flexible hybrid ionic liquid electrolyte
Gaurav Tatrari, Sourav Bhowmick, Andrei Filippov, Rong An, Faiz Ullah Shah
Abstract
Abstract The electrochemical and charge storage performance of a fluorine‐free structurally flexible hybrid pyrrolidinium‐based ionic liquid electrolyte (HILE) in a symmetric graphite‐based supercapacitor is thoroughly investigated. The HILE revealed thermal decomposition at above 230°C, a glass transition (T g ) temperature of below −70°C, and ionic conductivity of 0.16 mS cm −1 at 30°C. The chemical and electrochemical properties are investigated using a systematic variable temperature 1 H and 31 P NMR spectroscopy and diffusometry, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge‐discharge (GCD). The supercapacitor demonstrated a notable specific capacitance of 186 F g −1 at a scan rate of 1 mV s −1 and a specific capacitance of 122 F g −1 at a current density of 0.5 A g −1 . The maximum energy density of 48.8 Wh kg −1 , a power density of 450 W kg −1 at a current density of 0.5 A g −1 , and a potential window of 4 V were obtained. Altogether, this study demonstrates that the new HILE can be used in symmetric graphite‐based supercapacitors over a wide potential window of 4 V and a temperature range from −20°C to 90°C.