Integration of Ionogel Electrolytes with High Surface Area Carbon Papers for Flexible Supercapacitors.

摘要

Ionic liquid based gels, or ionogels, are an attractive electrolyte option for flexible energy storage devices. This is because the properties of ionic liquids (i.e., high ionic conductivity, wide electrochemical window, and negligible vapor pressure) enable a device architecture that can eliminate the heavy cases that encapsulate supercapacitors used today.;UV-polymerized ionogels are found to have tunable mechanical properties in addition to their favorable electrochemical properties. Their fabrication requires exposure to UV light, which complicates integration with opaque carbon electrodes. In-situ integration of UV polymerized ionogels with porous carbon electrodes is a field that has been minimally explored due to the technical considerations of the ionogel's curing process.;Here we show that UV-polymerized ionogels – specifically, 16-wt% poly(ethylene glycol) diacrylate (PEGDA) supported 1-ethyl-3-methyl imidazolium bis(trifuoromethylsulfonyl)imide (EMI TFSI) gels – can be synthesized in situ on commercial carbon papers in a coplanar architecture to yield a flexible supercapacitor device. First, we have developed a methodology to fabricate and test UV-polymerized ionogels with the most delicate of commercial carbon papers. Second, based on electroanalytical testing, we have found that each carbon paper yields different interfacial resistances between the neat ionic liquid (EMI TFSI) and its ionogel analog.;The results found here can be used as a decision-making tool in the selection of carbon electrodes and UV-polymerized ionogels. Furthermore, it has provided a way to fairly assess the wetting dynamics of different types of solid-state electrolytes with different carbon electrodes without the need of a standardized electrochemical cell.