Gel electrolyte membranes derived from co-continuous polymer blends

Summary, in English

Polymer gel electrolyte membranes were prepared by first casting films of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt, and poly(ethylene glycol) (PEG) monomethacrylate and dimethacrylate macromonomers. Polymerization of the macromonomers initiated by UV-irradiation then generated solid films having phase-separated morphologies with a microporous PVDF-HFP phase embedded in PEG-grafted polymethacrylates. Gel electrolyte membranes were finally prepared by allowing the films to take up solutions of LiTFSI in gamma-butyrolactone (gamma-BL). The PEG-grafted polymethacrylate in the membranes was found to host the largest part of the liquid electrolyte, giving rise to a highly swollen ionic conductive phase. Results by FTIR spectroscopy showed that the Li+ ions preferentially interacted with the ether oxygens of the PEG chains. The properties of the membranes were studied as a function of the ratio of PVDF-HFP to PEG-grafted polymethacrylate, as well as the degree of crosslinking, LiTFSI concentration, and liquid electrolyte content. The self-supporting and elastic gel membranes had ionic conductivities of 10(-3) S cm(-1) and a mechanical storage modulus in the range of 2.5 MPa in the tension mode at room temperature. Variation of the salt concentration showed the greatest effect on the membrane properties.

• Author: Anette Munch Elmér; Patric Jannasch
• Department/s: Centre for Analysis and Synthesis
• Publishing year: 2005
• Language: English
• Pages: 7896-7908
• Publication/Series: Polymer
• Volume: 46
• Issue: 19
• Links: http://dx.doi.org/10.1016/j.polymer.2005.06.079
• Document type: Journal article
• Publisher: Elsevier
• Topic: Chemical Sciences
• Keywords: Polymer gel electrolytes; Interpenetrating polymer blend networks; Vinylidene fluoride copolymers
• Status: Published
• ISBN/ISSN/Other: ISSN: 0032-3861