Ionic liquids and organic ionic plastic crystals utilizing small phosphonium cations

Vanessa Armel, David Velayutham, Jiazeng Sun, Patrick Howlett, Maria Forsyth, Douglas Macfarlane, Jennifer Pringle

Research output: Contribution to journalArticleResearchpeer-review

79 Citations (Scopus)


The development of new liquid and solid state electrolytes is paramount for the advancement of electrochemical devices such as lithium batteries and solar cells. Ionic liquids have shown great promise in both these applications. Here we demonstrate the use of phosphonium cations with small alkyl chain substituents, in combination with a range of different anions, to produce a variety of new halide free ionic liquids that are fluid, conductive and with sufficient thermal stability for a range of electrochemical applications. Walden plot analysis of the new phosphonium ionic liquids shows that these can be classed as good ionic liquids, with low degrees of ion pairing and/or aggregation, and the lithium deposition and stripping from one of these ionic liquids has been demonstrated. Furthermore, for the first time phosphonium cations have been used to form a range of organic ionic plastic crystals. These materials can show significant ionic conductivity in the solid state and thus are of great interest as potential solid-state electrolyte materials.
Original languageEnglish
Pages (from-to)7640 - 7650
Number of pages11
JournalJournal of Materials Chemistry
Issue number21
Publication statusPublished - 2011

Cite this