The electrochemical properties of solvent-free, quaternary polymer electrolytes based on a novel polymeric ionic liquid (PIL) as polymer host and incorporating 1g13TFSI ionic liquid, LiTFSI salt and nano-scale silica are reported. The PIL-LiTFSI-1g13TFSI-SiO(2) electrolyte membranes are found to be chemically stable even at 80 degrees C in contact with lithium anode and thermally stable up to 320 degrees C. Particularly, the quaternary polymer electrolytes exhibit high lithium ion conductivity at high temperature, wide electrochemical stability window, time-stable interfacial resistance values and good lithium stripping/plating performance. Batteries assembled with the quaternary polymer electrolyte at 80 degrees C are capable to deliver 140 mAh g(-1) at 0.1C rates with very good capacity retention. (C) 2011 Elsevier B.V. All rights reserved.