title: Study of carbamate-modified disiloxane in porous PVDF-HFP membranes: new electrolytes/separators for lithium-ion batteries.
abstract: A gel electrolyte membrane is obtained through the absorption of a carbamate-modified liquid disiloxane-containing lithium bis(trifluoromethane)sulfonimide (LiTFSI) by using macroporous poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) membranes. The porous membranes are prepared by means of a phase inversion technique. The resulting gel electrolyte membrane is studied by using differential scanning calorimetry, Fourier-transform infrared (FTIR) spectroscopy, and microscope mapping through coherent anti-Stokes Raman scattering (CARS) confocal microscopy and impedance spectroscopy. The ionic conductivity of the gel electrolyte is 10(-4) S cm(-1) at 20 °C. FTIR spectroscopy reveals interactions between LiTFSI and the carbonyl moiety of the disiloxane. No interactions between LiTFSI and PVDF-HFP or between disiloxane and PVDF-HFP are detected by FTIR spectroscopy. Furthermore, the distribution of the α and β/γ phases of PVDF-HFP and the homogeneous distribution of disiloxane/LiTFSI in the gel electrolyte membranes are examined by FTIR mapping. CARS confocal microscopy is used to image the three-dimensional interconnectivity, which reveals a reticulated structure of macrovoids in the porous PVDF-HFP framework. Owing to properties such as electrochemical and thermal stability of the disiloxane-based liquid electrolyte and the mechanical stability of the porous PVDF-HFP membrane, the gel electrolyte membranes presented herein are promising candidates for applications as electrolytes/separators in lithium-ion batteries.
authors.affiliation: Institute of Inorganic and Analytical Chemistry, University of Münster, Correnstr. 28/30, 48149 Münster (Germany), Fax: (+49) 251-8336705. s.jeschke@wwu.de.
authors.forename: Steffen
authors.initials: S
authors.lastname: Jeschke
authors.forename: Monika
authors.initials: M
authors.lastname: Mutke
authors.forename: Zhongxiang
authors.initials: Z
authors.lastname: Jiang
authors.forename: Burkhard
authors.initials: B
authors.lastname: Alt
authors.forename: Hans-Dieter
authors.initials: HD
authors.lastname: Wiemhöfer
mesh_terms: D002219:Carbamates / Q000737:chemistry*; D011211:Electric Power Supplies; D004573:Electrolytes / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D016062:Porosity; D012821:Silanes / Q000737:chemistry*
chemical_list: D002219:Carbamates; D004573:Electrolytes; D005782:Gels; D011145:Polyvinyls; D012821:Silanes; C545920:poly(vinylidene fluoride-co-hexafluoro propylene); C059468:disiloxane; D008094:Lithium
keywords: coherent anti-stokes raman scattering; ir spectroscopy; lithium-ion batteries; porous membranes; silicon