In this paper we report on the investigation of ionic liquid-based electrolytes with enhanced characteristics. In particular, we have studied ternary mixtures based on the lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt and two ionic liquids sharing the same cation (N-methyl-N-propyl pyrrolidinium, PYR13), but different anions, bis(trifluoromethanesulfonyl) imide (TFSI) and bis(fluorosulfonyl) imide (FSI). The LiTFSI-PYR13TFSI-PYR13FSI mixtures, found to be ionically dissociated, exhibit better ion transport properties (about 10(-3) S cm(-1) at -20 degrees C) with respect to similar ionic liquid electrolytes till reported in literature. An electrochemical stability window of 5 V is observed in carbon working electrodes. Preliminary battery tests confirm the good performance of these ternary electrolytes with high-voltage NMC cathodes and graphite anodes. Ionic liquid electrolyte mixtures, PYR13TFSI, PYR13FSI. (C) The Author(s) 2016. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: [email protected]. All rights reserved.