This work provides a study based on acyclic and cyclic sulfonium ionic liquids (ILs) with alkyl and ether-functionality on the cation paired with the bis{(trifluoromethyl)sulfonyl}imide, [TFSI] À , or the bis(fluorosulfonyl)imide, [FSI] À , as the counter anion. Herein, thermophysical characterisation of nine sulfonium-based ILs concerning the density, viscosity and conductiv-ity and thermal properties including phase transition behaviour and decomposition temperature is reported. The electrochemical stability of the ILs was also measured by cyclic voltammetry at a glassy carbon macro-disk electrode. All of the ILs showed low melting point, low viscosity and good conductivity and could serve as potential electrolytes for energy storage devices.[a] S.

Improved knowledge of interactions between crude oil and solid surfaces is of great importance for understanding oil spill responses as well as oil spill behaviour on land and in the near shore environment. Here, the goal was to study how crude oils with various physicochemical properties interacted with model shoreline surfaces. In addition, the influence of simulated weathering and addition of dispersant was investigated for selected crude oils. A quartz crystal microbalance was used to follow the adsorption from 13 different crude oils on silica, aluminosilicate and calcium carbonated surfaces, while the corresponding wettability alterations were followed by contact angle measurements. The polar crude oil components adsorbed in considerably higher amounts on the calcium carbonate surfaces than on the silica and aluminosilicate surfaces. The simulated weathering of oils resulted in increased adsorption onto both the silica and aluminosilicate surface, while it had little effect on the calcium carbonate surface. The presence of dispersants generally reduced the amounts adsorbed on the surfaces. In the presence of seawater, the crude oil with higher total acid number interacted strongest with the calcium carbonate surface.

The increasing need in the development of storage devices is calling for the formulation of alternative electrolytes, electrochemically stable and safe over a wide range of conditions. To achieve this goal, electrolyte chemistry must be explored to propose alternative solvents and salts to the current acetonitrile (ACN) and tetraethylammonium tetrafluoroborate (Et4NBF4) benchmarks, respectively. Herein, phenylacetonitrile (Ph-ACN) has been proposed as a novel alternative solvent to ACN in supercapacitors. To establish the main advantages and drawbacks of such a substitution, Ph-ACN + Et4NBF4 blends were formulated and characterized prior to being compared with the benchmark electrolyte and another alternative electrolyte based on adiponitrile (ADN). While promising results were obtained, the low Et4NBF4 solubility in Ph-ACN seems to be the main limiting factor. To solve such an issue, an ionic liquid (IL), namely 1-ethyl-3-methylimidazolium bis [(trifluoromethyl)sulfonyl] imide (EmimTFSI), was proposed to replace Et4NBF4. Unsurprisingly, the Ph-ACN + EmimTFSI blend was found to be fully miscible over the whole range of composition giving thus the flexibility to optimize the electrolyte formulation over a large range of IL concentrations up to 4.0 M. The electrolyte containing 2.7 M of EmimTFSI in Ph-ACN was identified as the optimized blend thanks to its interesting transport properties. Furthermore, this blend possesses also the prerequisites of a safe electrolyte, with an operating liquid range from at least −60 °C to +130 °C, and operating window of 3.0 V and more importantly, a flash point of 125 °C. Finally, excellent electrochemical performances were observed by using this electrolyte in a symmetric supercapacitor configuration, showing another advantage of mixing an ionic liquid with Ph-ACN. We also supported key structural descriptors by density functional theory (DFT) and COnductor-like Screening Model for Real Solvents (COSMO-RS) calculations, which can be associated to physical and electrochemical properties of the resultant electrolytes.

The development of the new electrolytes is essential to increase the energy density of the Li-ion batteries (LIBs)1. Solid electrolytes have attracted the interest of researchers as a next-generation electrolyte for LIBs due to their superior physical and chemical stability, large working potential windows, high transference number, and intrinsic safety2 3. In this study, we have designed and synthesized novel organic electrolytes for LIBs with a naphthalene mesogenic moiety bearing a lithium sulfonate group connected to two flexible long-alkyl chains. Starting from the lithium 4-aminonaphthalene-1-sulphonate building block, alkyl-tails were successfully doubly grafted on the amine function with N, N-di-isopropylethylamine in N, N-di-methylformamide. Once the reaction was completed, a washing, purification and neutralization step was carried out to obtain the desired product. Those electrolytes have been synthesized with 95 % purity as suggested from the NMR and mass spectrum. The chains length were differ by the number of alkyl groups in the chains from 8, 12, and 16, namely lithium 4 - (dioctylamino) naphthalene – 1 – sulfonate (BS-Li-8), lithium 4 - (didodecylamino) naphthalene – 1 - sulfonate (BS-Li-12), and lithium 4 - (dihexadecylamino) naphthalene – 1 – sulfonate (BS-Li-16). We have employed molecular dynamics simulations and various experimental techniques for a comprehensive understanding of the bulk structure and transport mechanism of those electrolytes. Simulated static structural factor, radial distribution functions, and experimental small angle x-ray scattering spectrum suggest that degree of aggregation, ionic correlations, and structural properties of materials at the nanoscale of the electrolyte molecules varies with the length of the alkyl chains. The Li+ ion mobility calculated from experimental Electrochemical Impedance Spectra, using a symmetrical cell with blocking electrodes and molecular dynamics simulations reveal that BS-Li-12 is the most conductive (approximately 10-3 S / cm at 1400 C) owing to the weaker cation-anion correlation than others. It was observed that the conductivity of the Li+ ions is directly related to the coordination number between Li+ and anionic centers, since, in BS-Li-12, Li+ coordinates with two anionic centers while for others, it is three. During the conduction, Li+ move from one anionic site to another by changing their coordination number with anion. We successfully synthesized next-generation organic electrolytes with well-organized Li+ conduction channels. The comprehensive study of the influence of the nonpolar alkyl chain on the bulk structural arrangement and conductivity of such electrolytes will contribute significantly to the development of future LIBs electrolytes. References: (1) Armand, M.; Tarascon, J.-M. Building Better Batteries. Nature 2008, 451 (7179), 652–657. https://doi.org/10.1038/451652a. (2) Manthiram, A.; Yu, X.; Wang, S. Lithium Battery Chemistries Enabled by Solid-State Electrolytes. Nature Reviews Materials 2017, 2 (4), 16103. https://doi.org/10.1038/natrevmats.2016.103. (3) Quartarone, E.; Mustarelli, P. Electrolytes for Solid-State Lithium Rechargeable Batteries: Recent Advances and Perspectives. Chem. Soc. Rev. 2011, 40 (5), 2525–2540. https://doi.org/10.1039/C0CS00081G. Figure 1