Room temperature ionic liquid electrolyte

Hewlett, P. C., Brack, N., Hollenkamp, A. E, Forsyth, M., and MacFarlane, D. R., Characterization of the lithium surface in N-methyl-N-alkylpyrrolidinium bis(trifluoromethanesulfonyl)imide room-temperature ionic liquid electrolytes, /. Electrochem. Soc., 153, A595-A606,2006. 

Peng C X, Yang L, Zhang Z X, et al. Investigation of the anodic behavior of Al current collector in room temperature ionic liquid electrolytes. Electrochim. Acta. 2008. 53, 4764-4772. 

FIGURE 2.70 Cyclic voltammograms for [EMIMllBFJ at 5 mV s" . (Sillars, F. B. et al. 2012. Variation of electrochemical capacitor performance with room temperature ionic liquid electrolyte viscosity and ion size. Physical Chemistry Chemical Physics 14 6094-6100. Reproduced by permission of The Royal Society of Chemistry.)... 

Ui, K. Yamamoto, K. IsMkawa, K. Minami, T. Takeuchi, K Itagaki, M. Watanabe, K. Koura, N., Development of non-flammable lithium secondary battery with room-temperature ionic liquid electrolyte performance of electroplated A1 film negative electrode, J. Power Sources 2008,183,347-350. 

KuboM, T Okuyama, T Ohsald, T Takami, N, Lithium-air batteries using hydrophobic room temperature ionic liquid electrolyte, J. Power Sources, 2004,146, 766-769. 

Walsh DA, Lovelock KRJ, Licence P (2010) Ultramicroelectrode voltammetry and scanning electrochemical microscopy in room-temperature ionic liquid electrolytes. Chem Soc Rev 39 4185 194... 

N. Koura, H. Nagase, A. Sato, S. Kumakura, K. Takeuchi, K. Ui, T. Tsuda and C. K. Loong, Electroless plating of aluminum from a room-temperature ionic liquid electrolyte . Journal of the Electrochemical Society, 155, (2008), D155-D157. 

Seki S, Kobayashi Y, Miyashiro H, Ohno Y, Mita Y, Terada N, Charest P, Guerfi A, Zaghib K (2008) Compatibility of N-methyl-N-propylpyrrolidinium cation room-temperature ionic liquid electrolytes and graphite electrodes. J Phys Chem C 112 16708-16713... 

Recently, a eutectic mixture of choline chloride and urea (commercially known as Reline) was used as a medium from which CdS, as well as CdSe and ZnS, thin films were electrodeposited for the first time [53]. Reline is a conductive room-temperature ionic liquid (RTIL) with a wide electrochemical window. The voltammetric behavior of the Reline-Cd(II)-sulfur system was investigated, while CdS thin films were deposited at constant potential and characterized by photocurrent and electrolyte electroabsorbance spectroscopies. 

Widegren, J.A. et al. Electrolytic conductivity of four imidazolium-based room-temperature ionic liquids and the effect of a water impurity, /. Chem. Thermo-dyn., 37, 569,2005. 

Ding, S.F., Xu, M.Q., Zhao, G.C., and Wei, X.W., Direct electrochemical response of Myoglobin using a room temperature ionic liquid, l-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate, as supporting electrolyte, Electrochem. Commun., 9, 216-220,2007. 

Qin, W., Wei, H., and Li, S. F. Y, 1,3-Dialkylimidazolium-based room-temperature ionic liquids as background electrolyte and coating material in aqueous capillary electrophoresis, ]. Chromatogr. A, 985, 447-454, 2003. 

Industrial exploitation of ionic liquids is in its early days (Freemantle, 2000). The nse of ionic liquids in industry is seen as being highly speculative, but progress is being made. Room temperature ionic liquids have been stndied actively since their discovery in the 1970s, predominantly for their possible application as battery electrolytes. Work on the exploitation of ionic liquids as reaction media started in the early 1980s, but only recently has it attracted industrial interest. 

Room-temperature ionic liquids are attractive due to their chemical and thermal stability, negligible vapor pressure, high ionic conductivity, and ample electrochemical window. Their properties can be varied by a rational choice of the cations and of the anions and can represent an important iodide source for an I /I3 -based electrolyte (Fig. 17.12). 

Because of its high reactivity (—1.67 V vs. NHE), the electrodeposition of aluminum from aqueous solutions is not possible. Therefore, electrolytes for A1 deposition must be aprotic, such as ionic liquids or organic solvents. The electrodeposition of aluminum in organic solutions is commercially available (SIGAL-process [56, 57]) but due to volatility and flammability there are some safety issues. Therefore, the development of room-temperature ionic liquids in recent years has resulted in another potential approach for aluminum electrodeposition. Many papers have been published on the electrodeposition of aluminum from chloroaluminate (first... 

Electrochemical methods are sensitive to the extent that it is possible to detect a trace of electroactive species in electrolyte solutions. Because of this distinctive feature, electrochemical methods have been developed and utilized for analytical purposes. The detection method used is known as polarography. For the electrochemical study purification of the electrolyte solutions is therefore important. As for most aqueous and organic electrolyte solutions, there are various well-established techniques for purifying both solvents and electrolytes. In the case of room-temperature ionic liquids, it is especially important to purify the starting materials used for preparing the ionic liquids. 

Room-temperature ionic liquids (denoted RTILs) have been studied as novel electrolytes for a half-century since the discovery of the chloroaluminate systems. Recently another system consisting of fluoroanions such as BF4 and PFg , which have good stability in air, has also been extensively investigated. In both systems the nonvolatile, noncombustible, and heat resistance nature of RTILs, which cannot be obtained with conventional solvents, is observed for possible applications in lithium batteries, capacitors, solar cells, and fuel cells. The nonvolatility should contribute to the long-term durability of these devices. The noncombustibility of a safe electrolyte is especially desired for the lithium battery [1]. RTILs have been also studied as an electrodeposition bath [2]. 

Room-temperature ionic liquids are the promising electrolytes for the electrodeposition of various metals because they have the merits of both organic electrolytes and high-temperature molten salts. Ionic liquids can be used in a wide temperature range, so temperatures can be elevated to accelerate such phenomena as nucleation, surface diffusion and crystallization associated with the electrodeposition of metals. In addition the process can be safely constracted because ionic liquids are neither flammable nor volatile if they are kept below the thermal decomposition temperature of the organic cations. 

Matsumoto H, Sakaebe H, Tatsumi K. Preparation of room temperature ionic liquids based on aliphatic onium cations and asymmetric amide anions and their electrochemical properties as a lithium battery electrolyte. J. Power Sources. 2005. 146, 45-50. 

Singh B, Sekhon S S. Polymer electrolytes based on room temperature ionic liquid 2,3-dimethyl-1-octylimidazolium triflate. J. Phys. Chem. B. 2005. 109, 16539-16543. 

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