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Ionic liquids (ILs) are highly tailorable materials with unique physical and chemical properties that set them apart from conventional organic solvents. As the library of readily accessible ILs continues to grow, so too does their relevance in applications ranging from material processing to electrochemical energy storage as solvents capable of accessing new chemistries disallowed by traditional chemicals. While a great deal of interest has been directed towards imidazolium and quaternary ammonium based ionic liquids, there are other understudied classes of cations which have potentially favorable properties for energy related applications. One such class is that with boronium cations. These cations have a unique structure with a formally negative boron flanked by positive nitrogens. This inherently zwitterionic structure presents interesting possibilities for electrochemical applications. To date only a handful of boronium cation-based ionic liquids have been thoroughly characterized despite exhibiting impressive electrochemical stabilities (> 5.0 V). In the present study we synthesized a series of ILs with novel boronium cations coupled with the bis(trifluoro-methanesulfonyl)imide anion. We then characterized the electrochemical and physical properties of these boronium ionic liquids by techniques such as cyclic voltammetry, broadband dielectric spectroscopy, oscillatory shear rheology, and thermogravimetric analysis. We will discuss how systematic variations in boronium cation structure impacted electrochemical and physical properties.
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This content will become publicly available on January 9, 2026
A Comprehensive Review of the Thermophysical Properties of Energetic Ionic Liquids
Energetic ionic liquids (EILs) have various industrial applications because they release chemically stored energy under certain conditions. They can avoid some environmental problems caused by traditionally used toxic fuels. EILs, which are environmentally friendly and safer, are emerging as an alternative source for hypergolic bipropellant fuels. This review focuses on the crucial thermophysical properties of the EILs. The properties of imidazolium and triazolium-based ionic liquids (ILs) are discussed here. The thermophysical properties addressed, such as glass transition temperature, viscosity, and thermal stability, are critical for designing EILs to meet the need for sustainable energy solutions. Imidazolium-based ILs have tunable physical properties making them ideal for use in energy storage while triazolium-based ILs have thermal stability and energetic potential. As a result, it is important to understand and compile thermophysical properties so they can help researchers synthesize tailored compounds with desirable characteristics, advancing their application in energy storage and propulsion technologies.
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- Award ID(s):
- 2200423
- PAR ID:
- 10617349
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Energies
- Volume:
- 18
- Issue:
- 2
- ISSN:
- 1996-1073
- Page Range / eLocation ID:
- 267
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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