Polymer electrolyte membranes by in situ polymerization of poly(ethylene carbonate‐co‐ethylene oxide) macromonomers in blends with poly(vinylidene fluoride‐co‐hexafluoropropylene)

Abstract

Salt-containing membranes based on polymethacrylates having poly(ethylene carbonate-co-ethylene oxide) side chains, as well as their blends with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), have been studied. Self-supportive ion conductive membranes were prepared by casting films of methacrylate functional poly(ethylene carbonate-co-ethylene oxide) macromonomers containing lithium bis(trifluorosulfonyl)imide (LiTFSI) salt, followed by irradiation with UV-light to polymerize the methacrylate units in situ. Homogenous electrolyte membranes based on the polymerized macromonomers showed a conductivity of 6.3 Â 10 À6 S cm À1 at 20 8C. The preparation of polymer blends, by the addition of PVDF-HFP to the electrolytes, was found to greatly improve the mechanical properties. However, the addition led to an increase of the glass transition temperature (T g ) of the ion conductive phase by $5 8C. The conductivity of the blend membranes was thus lower in relation to the corresponding homogeneous polymer electrolytes, and 2.5 Â 10 À6 S cm À1 was recorded for a membrane containing 10 wt % PVDF-HFP at 20 8C. Increasing the salt concentration in the blend membranes was found to increase the T g of the ion conductive component and decrease the propensity for the crystallization of the PVDF-HFP component. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: [79][80][81][82][83][84][85][86][87][88][89][90] 2007

Solid polymer electrolytes based on lithium bis(trifluoromethanesulfonyl)imide/poly(vinylidene fluoride -co-hexafluoropropylene) for safer rechargeable lithium-ion batteries

“…In relation to lithium salts, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is widely used in SPE development, considering its excellent electrochemical properties, high chemical and thermal stability and because its large and bulky anions can be highly delocalized to facilitate the salt dissociation and solubility [15,16].…”

Nafion/Poly Vinylidene Fluoride (PVDF) Blends for Polymer Electrolyte Membranes Application

“…The weight loss in the range 250 -400 °C is associated with degradation of -SO 3 H groups and polyether side chains of Nafion. [14][15] The weight loss observed in the range of 400 -480 °C is associated with thermal degradation of fluorocarbon chains of PTFE (polytetrafluoroethelyne) backbone of Nafion. [10][11][12] The TGA result shows that Nafion-PVDF blend membranes are more thermally stable compared to pure Nafion.…”

“…[6][7] In addition, the PVDF copolymer has sufficient mechanical strength and dimensional stability, and lower reactant permeability. [6][7][8] In this study, Nafion is blended with poly-vinylidene fluoride copolymer (PVDF) in different blending ratios. The effect of the blending ratios on the electrochemical properties, thermal properties, water-uptake properties and methanol permeability is investigated.…”

Enhanced mechanical strength and conductivity of PVFM based membrane and its supporting polymer electrolytes

“…The application of GPEs is one of the effective ways to solve the safety issues because of the absence of risk for leakage of electrolytes . In recent years, many kinds of polymer matrixes have been researched, including poly(ethylene oxide) (PEO), poly(acrylonitrile) (PAN), poly(methyl methacrylate) (PMMA), poly (vinylidene fluoride) (PVDF), and poly (vinylidene fluoride‐hexafluoro propylene) (PVDF‐HFP), and so on. Besides, several new kinds of polymer matrixes are being developed for superior electrochemical properties.…”