Ternary polymer electrolytes containing pyrrolidinium-based polymeric ionic liquids for lithium batteries

The electrochemical properties of solvent-free, ternary polymer electrolytes based on a novel poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide polymeric ionic liquid (PIL) as polymer host and incorporating PYR14TFSI ionic liquid and LiTFSI salt are reported. The PIL-LiTFSI-PYR14TFSI electrolyte membranes were found to be chemically stable even after prolonged storage times in contact with lithium anode and thermally stable up to 300 degrees C. Particularly, the PIL-based electrolytes exhibited acceptable room temperature conductivity with wide electrochemical stability window, time-stable interfacial resistance values and good lithium stripping/plating performance. Preliminary battery tests have shown that Li/LiFePO4 solid-state cells are capable to deliver above 140mAh g(-1) at 40 degrees C with very good capacity retention up to medium rates. (C) 2009 Elsevier B.V. All rights reserved.