Composition as a Means to Control Morphology and Properties of Epoxy Based Dual-Phase Structural Electrolytes
Artikel i vetenskaplig tidskrift, 2014

Structural electrolytes were prepared using a fully formulated commercially available high performance epoxy resin (MTM57) and an ionic liquid based electrolyte: lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) dissolved in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI). Through a systematic study, the composition of the formulations was found to have a greater effect than the curing temperature on the morphology and properties of the resulting structural electrolytes. The presence of lithium salt is essential to form a structurally homogeneous electrolyte. Bicontinuous morphologies containing continuous (coarse) epoxy networks surrounded by connected spherical epoxy nodules were obtained with different length scales upon varying the lithium salt concentration. Increasing the LiTFSI concentration improved the miscibility of MTM57 with the electrolyte and decreased the characteristic length scale of the resulting bicontinuous microstructure. The properties of the structural electrolytes correlated with the morphology, showing increased Youngs modulus and decreased ionic conductivity with increasing lithium salt concentration. The miscibility of the epoxy system with the electrolyte was also improved by substitution of EMIM-TFSI with an equal weight of an aprotic organic solvent, propylene carbonate (PC); however, the window of PC concentrations which resulted in structural electrolytes with bicontinuous microstructures was very narrow; at PC concentrations above 1 wt %, gel-like polymers with no permanent mesoporosity were obtained.


N. Shirshova

Imperial College London

University of Durham

A. Bismarck

Universität Wien

Imperial College London

E. S. Greenalgh

Imperial College London

Patrik Johansson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

G. Kalinka

Bundesanstalt für Materialforschung und -prüfung (BAM)

Maciej Jozef Marczewski

Chalmers, Teknisk fysik, Kondenserade materiens fysik

M. S. Shaffer

Imperial College London

M. Wienrich

Bundesanstalt für Materialforschung und -prüfung (BAM)

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 118 28377-28387