The synthesis and physicochemical properties of a series of non-flammable, thermally stable alkyl ether containing piperidinium ionic liquid electrolytes, containing lithium bis(trifluoromethanesulfonyl)imide, are described along with the superior performance of a lithium-ion supercapacitor containing a piperidinium electrolyte compared to a standard carbonate-based electrolyte at 100 °C.