Glyme−Lithium Bis(trifluoromethanesulfonyl)imide and Glyme−Lithium Bis(perfluoroethanesulfonyl)imide Phase Behavior and Solvate Structures

Crystal structures of glyme solvates with LiTFSI and LiBETI (TFSI^- = bis(trifluoromethanesulfonyl)imide, BETI^- = bis(perfluoroethanesulfonyl)imide) have been determined including (monoglyme)<INF>1</INF>:LiBETI, (diglyme)<INF>2</INF>:LiTFSI, (diglyme)<INF>1/2</INF>:LiTFSI, and low-temperature (triglyme)<INF>1</INF>:LiBETI. These solvates, combined with the phase behavior of the salts with various glymes from DSC analysis, provide insight into the molecular interactions of lithium salts in ethoxy solvents commonly used for solid polymer and liquid electrolytes. Many of the solvates appear to undergo order−disorder solid phase transitions. These are the first reported crystal structures containing the BETI^- anion.