Li+ conducting polymer electrolyte based on ionic liquid for lithium and lithium-ion batteries

Polymer electrolyte (PE), based on PVdF-co-HFP polymer network and MePrPipNTf(2) + LiNTf2 ionic liquid (MePrPip: N-methyl-N-propylpiperidinium cation, NTf2 is bis(trifluoromethanesulphonyl)imide anion) was prepared. PE contained small amounts of vinylene carbonate. The performance of metallic-lithium and graphite (G) anodes working together with the electrolyte were tested with the use of: electrochemical impedance spectroscopy (EIS), galvanostatic charging/discharging and scanning electron microscopy (SEM). Specific conductance of the membrane was ca. 4 mS cm(-1) at 25 degrees C with activation energy of 14.35 kJ mol(-1). Scanning electron microscopy images showed that the charged/discharged. graphite anodes differed in morphology from the pristine material. The surface of graphite flakes was covered with small crystals with a diameter of ca. 1 mu m (the solid electrolyte interface, SEI). When the graphite anode was soaked with the 1 M LiPF6 solution in PC+ DMC (propylene carbonate and dimethyl carbonate, respectively), before the G vertical bar PE vertical bar Li cell assembling, its reversible capacity was ca. 340 mAh g(-1) (after the 50th cycle). (C) 2013 Elsevier Ltd. All rights reserved.