Dynamic Pulse Power and Energy of Ionic-Liquid-Based Supercapacitor for HEV Application

Asymmetric electrochemical double-layer carbon supercapacitors (AEDLCs) with N-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR(1(2O1))TFSI) ionic-liquid electrolyte can safely cycle above room temperature with maximum cell voltage as high as 3.7 V over several thousand cycles and are thus promising candidates for hybrid electric vehicle (HEV) applications. Here, we report the energy and power performance of the PYR(1(2O1))TFSI-based AEDLCs in the -30 to 60 degrees C temperature range evaluated by the conventional galvanostatic cycling and by the United States Advanced Battery Consortium and the U.S. Department of Energy (DOE) FreedomCAR benchmark protocols. The most outstanding finding is that the ionic-liquid-based supercapacitor meets the dynamic power and energy capability targets stated by DOE for power-assist HEVs.