Binary ionic liquid electrolyte

Wang, P. Zakeeruddin, S. M Humphry-Baker, R. Gratzel, M. (2004a). A binary ionic liquid electrolyte to achieve 7% power conversion efficiencies in dye-sensitized solar cells. Chemistry of Materials, 16, 2004,2694-2696. 

Modeling of Ionic Liquid Electrolytes Room-Temperature Ionic Liquid-Based Binary Electrolytes... 

Fox ET, Paillard E, Borodin O, Henderson WA (2013) Physicochemical properties of binary ionic liquid-apiotic solvent electrolyte mixtures. J Phys Chem C 117 78-84... 

In another work, poly(l-oligo(ethylene glycol) methacrylate-3-methyUmidazolium chloride) was synthesized as the ionic liquid polymer, exhibiting ionic conductivity of 1.0 x 10 S cm at room temperature. Ionic liquid-based electrolytes were prepared by the addition of the ionic polymer poly(l-oligo(ethylene glycol) methacrylate-3-methylimidazolium chloride) to a binary ionic liquid mixture and Lil/E. It was shown that the ionic conductivity decreases with increasing polymer content, and the maximum conductivity achieved (2.0 x 10 S cm ) was obtained at a polymer content of 10 vt%. DSSC assembled with the optimized electrolyte presented overall efficiency conversion of 6.1%. ... 

A wide variety of data for mean ionic activity coefficients, osmotic coefficients, vapor pressure depression, and vapor-liquid equilibrium of binary and ternary electrolyte systems have been correlated successfully by the local composition model. Some results are shown in Table 1 to Table 10 and Figure 3 to Figure 7. In each case, the chemical equilibrium between the species has been ignored. That is, complete dissociation of strong electrolytes has been assumed. This assumption is not required by the local composition model but has been made here in order to simplify the systems treated. 

Two activity coefficient models have been developed for vapor-liquid equilibrium of electrolyte systems. The first model is an extension of the Pitzer equation and is applicable to aqueous electrolyte systems containing any number of molecular and ionic solutes. The validity of the model has been shown by data correlation studies on three aqueous electrolyte systems of industrial interest. The second model is based on the local composition concept and is designed to be applicable to all kinds of electrolyte systems. Preliminary data correlation results on many binary and ternary electrolyte systems suggest the validity of the local composition model. 

In this study we restrict our consideration by a class of ionic liquids that can be properly described based on the classical multicomponent models of charged and neutral particles. The simplest nontrivial example is a binary mixture of positive and negative particles disposed in a medium with dielectric constant e that is widely used for the description of molten salts [4-6], More complicated cases can be related to ionic solutions being neutral multicomponent systems formed by a solute of positive and negative ions immersed in a neutral solvent. This kind of systems widely varies in complexity [7], ranging from electrolyte solutions where cations and anions have a comparable size and charge, to highly asymmetric macromolecular ionic liquids in which macroions (polymers, micelles, proteins, etc) and microscopic counterions coexist. Thus, the importance of this system in many theoretical and applied fields is out of any doubt. 

Early in their work on molten salt electrolytes for thermal batteries, the Air Force Academy researchers surveyed the aluminum electroplating literature for electrolyte baths that might be suitable for a battery with an aluminum metal anode and chlorine cathode. They found a 1948 patent describing ionicaUy conductive mixtures ofAlCh and 1-ethylpyridinium halides, mainly bromides [6]. Subsequently the salt 1-butylpyridinium chloride -AICI3 (another complicated pseudo-binary) was found to be better behaved than the earlier mixed halide system, so the chemical and physical properties were measured and published [7]. I would mark this as the start of the modern era for ionic liquids, because for the first time a wider audience of chemists started to take interest in these totally ionic, completely nonaqueous new solvents. 

Binary room-temperature ionic liquid (RTIL)-based electrolytes have attracted significant attention because of their negligible vapor pressure good thermal and electrochemical stability in the range of 5.3 V [83] good dissolution properties with many organic and inorganic compounds and lithium salts and low flammability [84]. 

Hayamizu, K., Tsuzuki, S., Seki, S., Ohno, Y, Miyashiro, H. and Kobayashi, Y, Quaternary ammonium room-temperature ionic liquid including an oxygen atom in side chain/lithium salt binary electrolytes ionic conductivity and H, Li, and NMR studies on diffusion coefficients and local motions, J. Phys. Chem. B 112,1189-1197 (2008). 

Bidikoudi, M., Stergiopoulos, T., Likodimos, V., Romanos, G.E., Francisco, M Iliev, B Adamova, G., Schubert, T.J.S., and Falaras, P. (2013) Ionic liquid redox electrolytes based on binary mixtures of 1-alkyl-methylimidazolium tricyanomethanide with l-methyl-3-propylimidazolium iodide and implication in dye-sensitized solar cells. /, Mater. Chem. A, 1, 10474-10486. 

Poly(ionic liquid) brushes with terminated ferrocene units acted similarly, while the interfacial resistance was probed by hexacyanoferrate [457]. Chemical and electrochemical switching of local pH at an electrode-grafted poly(vinyl pyridine) brush again allowed modulation of hexacyanoferrate chemistiy (Fig. 43) [458]. Octacyanomolybdate was used as catalyst for the oxidation of ascorbic acid [459]. Even heteropolyanions (Keggin ions) could be entrapped in polymer films electrochemicaUy [460]. Further, thermoresponsive or pH-responsive cationic copolymer films modulated the hexacyanoferrate or ferrocenedicarboxyUc acid electrochemistry by temperature or variatimi of pH and perchlorate concentration, respectively [461-463]. Besides these complexes with cationic polyelectrolyte films, electroactive cationic counterions (e.g., the europium couple) interacted with anionic networks [464]. Similarly, copper ions within a PAA matrix [367] allowed the construction of actuators [465]. Besides these binary systems (poly-electrolyte/electroactive counterions), multiresponsive electrode modification with an interpenetrating gel network of poly(acrylic) acid and poly(diethyl acrylamide) allowed the modulation of hexacyanoferrate electrochemistry [368]. 

As it is perfectly known, room temperature molten salts or ionic liquids (ILs) are charged complex fluids formed exclusively by ions. They can be seen as an infinitely concentrated electrolyte solution, and one can think about these systems as the opvposite limit to that of the applicability of the DH theory of ions solutions. It is well-known that a polar network exists in these systems, as can be seen for example in (Wei Jiang et al., 2007), so, from the theoretical perspective, one expects that a pseudolattice model is particularly well adapted to the peculiarities of ILs. Indeed, Turmine and coworkers (Bou Malham et al., 2007 Bouguerra et al. 2008) proved that the so called Bahe-Varela (BV) pseudolattice theory of electrolyte solutions is capable of accoxmting for the thermodynamic properties of binary and ternary mixtures of ILs up to the limit of pure IL. 

An application to one binary mixture of a volatile electrolyte and water will illustrate the choice of parameters H and K, an approach is proposed to represent the vapor-liquid equilibrium in the whole range of concentration. Ternary mixtures with one acid and one base lead to the formation of salts and high ionic strengths can be reached. There, it was found useful to take into account... 

From a global assessment of these results, it seems inescapable to conclude that mean-field behavior does not remain valid asymptotically close to the critical point. Rather, ionic systems seem to show Ising-to-mean-field crossover. Such a crossover has been a recurring result observed near liquid-liquid consolute points in Coulombic electrolyte solutions, in ternary aqueous electrolyte solutions containing an organic cosolvent, and in binary aqueous solutions of NaCl near the liquid-vapor critical line. 

Reactive absorption processes occur mostly in aqueous systems, with both molecular and electrolyte species. These systems demonstrate substantially non-ideal behavior. The electrolyte components represent reaction products of absorbed gases or dissociation products of dissolved salts. There are two basic models applied for the description of electrolyte-containing mixtures, namely the Electrolyte NRTL model and the Pitzer model. The Electrolyte NRTL model [37-39] is able to estimate the activity coefficients for both ionic and molecular species in aqueous and mixed solvent electrolyte systems based on the binary pair parameters. The model reduces to the well-known NRTL model when electrolyte concentrations in the liquid phase approach zero [40]. 

Gibbs monolayers are widespread. The simplest system is that of the surface of a fully miscible binary liquid. More complex ones are monolayers of uncharged molecules adsorbed from dilute solutions (example aliphatic alcohols from aqueous solution) electrolytes surfactants (non-ionic or ionic) polymers and polyelectrolytes and yet more. On the other hand, the methods for characterizing... 

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