N-Allyl-N-methyl piperidinium bis(trifluoromethanesulfonyl)imide as a co-solvent in Li-ion batteries

摘要

Mixtures of an ionic liquid (IL) with organic solvents and a lithium salt have been studied in order to develop new electrolytes for lithium-ion cells with enhanced safety profiles. In this work, N-allyl-N-methylpiperidinium bis(trifluoromethanesulfonyl)imide (PP_(1A)TFSI) was synthesized and characterized to exhibit high decomposition temperature and wide electrochemical stability window. The evaluation of the coin cell LiFePO_4/Li with the mixed electrolyte based on PP_(1A)TFSI with 0.35 mol/kg LiTFSI, and 30 wt% VC/DMC (1:1) shows a nice reversibility and cycle performances. All above prove that PP_(1A)TFSI is one of the most promising safety electrolytes of Li-ion battery.