As a result of the development of 4th and 5th generation recyclable batteries, new materials are one of the critical topics in current studies, especially for electrolyte and electrode designs. In the latest years, research related to new electrochemical materials has experienced a great upgrade. One of the most promising materials are ionic liquids (ILs), which are organic salts formed by a cation and an anion whose melting point is below 100ºC. The tuneability of the properties of ILs from the infinity combinable anions and cations and the possibility of introducing functional groups in their alkyl chains, make these fluids appropriate for many industrial applications as for example, electrolytes in mixtures of ILs and inorganic salts, mainly lithium salts.
ILs confinement in a matrix scaffold improves safety manipulation while reducing the possibility of spillage. This immobilization of ionic liquids (or mixtures with inorganic salts) is known as gelation, and the resulting material is denominated ionogel or ionic gels.
The purpose of this work is to compare the physicochemical character of two different gelation methods. One of them polymeric using Poly (vinylidene fluoride) (PVDF) as supporting matrix, and the other one sol-gel by using a silica matrix. The selected IL is N-butyl-N-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide [BMPyrr][TFSI] and its binary mixture with [Li][TFSI] salt at different concentrations.