Gel electrolyte membranes derived from co-continuous polymer blends
Research output: Contribution to journal › Article
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.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Publication status||Published - 2005|
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)