Gel electrolyte membranes derived from co-continuous polymer blends

Research output: Contribution to journalArticle

Abstract

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.

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Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Chemical Sciences

Keywords

  • Polymer gel electrolytes, Interpenetrating polymer blend networks, Vinylidene fluoride copolymers
Original languageEnglish
Pages (from-to)7896-7908
JournalPolymer
Volume46
Issue number19
Publication statusPublished - 2005
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Polymer and Materials Chemistry (LTH) (011001041)