High voltage electrochemical double layer capacitor containing mixtures of ionic liquids and organic carbonate as electrolytes

Using a mixture of PC/PYR14TFSI as electrolyte, EDLCs with an operative voltage of 3.5 V and ESR comparable with that of conventional electrolyte have been realized. The combination of high operative voltage and low ESR enable the realization of EDLCs with high energy and high power. Moreover, the use of PC/PYR14TFSI mixture also guarantees a remarkable cycling stability, as evidenced by a capacitance loss of only 5% after 100,000 cycles carried out at 3.5 V.

Research highlights
► Mixtures of PC/PYR14TFSI are promising electrolytes for EDLCs.
► PC/PYR14TFSI-based EDLCs display at RT operative voltage of 3.5 V and low ESR.
► PC/PYR14TFSI-based EDLCs display high energy and high power at RT.
► PC/PYR14TFSI-based EDLCs display capacitance loss of only 5% after 100,000 cycles at 3.5 V.