Phase Behavior of Ionic Liquid-LiX Mixtures: Pyrrolidinium Cations and TFSI- Anions

Phase diagrams are reported for mixtures between bis (trifluoromethanesulfonyl)imide (TFSI-) salts containing Li+ and N-alkyl-N-methylpyrrolidinium (PYR1R+) cations. The latter salts readily form both room temperature ionic liquids and plastic crystalline phases. Mixed salt crystalline phases are found which are likely to influence the performance of such mixed salt systems when utilized as electrolytes for electrochemical devices as well as give insight into ionic liquid-solute interactions.