PEO-Based Polymer Electrolytes with Ionic Liquids and Their Use in Lithium Metal-Polymer Electrolyte Batteries

The influence of adding the room-temperature ionic liquid (RTIL) -methyl--propylpyrrolidinium bis(trifluoromethanesulfonyl)imide to polymer electrolytes and the use of these electrolytes in solid-state batteries has been investigated. polymer electrolytes with various mole fractions (, 1.08, 1.73, 1.94, 2.15, and 3.24) were prepared. The addition of up to a 3.24 mole fraction of the RTIL to electrolytes, corresponding to a RTIL/PEO weight fraction of up to 1.5, resulted in freestanding and highly conductive electrolyte films reaching at . The electrochemical stability of was significantly improved by the addition of LiTFSI. cells using the polymer electrolyte with showed excellent reversible cyclability with a capacity fading of 0.04% per cycle over several hundreds cycles at . The incorporation of the RTIL into lithium metal-polymer electrolyte batteries has resulted in a promising improvement in performance at moderate to low temperatures.