LiTFSI in 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)amide: a possible electrolyte for ionic liquid based lithium ion batteries.

In this communication, we show that the combination of 1 M lithium bis(trifluoromethylsulfonyl)amide and 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)amide (LiTFSI/[Py1,4]FSI) can be regarded as a possible stable electrolyte for IL based lithium ion batteries. We compare the charge-discharge results with the electrolyte 1 M LiTFSI in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([Py1,4]TFSI) on an electrodeposited Ge electrode and show using a charge-discharge analysis and Raman spectroscopy that 1 M LiTFSI/[Py1,4]FSI is advantageous in maintaining the charge capacity as well as electrolyte stability at high current densities.