All Solid-State Symmetrical Activated Carbon Electrochemical Double Layer Capacitors Designed with Ionogel Electrolyte

Abstract

The concept of an all solid state leakage free electrochemical double layer capacitor is presented. It combines two activated carbon electrodes assembled with an ionogel solid state electrolytic separator. This ionogel is a chemical gel, which consists of a room temperature ionic liquid, 1-Ethyl-3-Methyl Imidazolium Bis(trifluoromethanesulfonylimide) confined within a continuous monolithic silica host network, preventing any leakage of the electrolyte meanwhile preserving its liquid physical properties. The ionogel based EDLC can be operated up to 3 V with a device capacitance of 20 F.g−1 (80 F.g−1 per electrode) and exhibits no noticeable fade in capacitance after 10,000 cycles.