Geminal pyrrolidinium and piperidinium dicationic ionic liquid electrolytes. Synthesis, characterization and cell performance in LiMn2O4 rechargeable lithium cells

Dicationic ionic liquids are promising solvents for safe high performance Li-ion battery applications. In this work, we report on the synthesis and characterization of new electrolytes based on geminal dicationic pyrrolidinium and piperidinium bis(trifluoromethane)sulfonimide ionic liquids, where the two cations are linked by variable length oxyethylene chain spacers. All 1 M LiTFSI doped synthesized electrolytes are thermally stable up to 300 °C, and they exhibited remarkable electrochemical stability window up to 6.0 V vs. Li/Li+.