Liquid oxide electrolytes

MIXTURES OF LIQUID OXIDE ELECTROLYTES 5.13.1. The Liquid Oxides... 

Figure 3.6 shows the various relationships between the energy levels of solids and liquids. In electrolytes three energy levels exist, Ep, redox, Eox and Ered- The energy levels of a redox couple in an electrolyte is controlled by the ionization energy of the reduced species Ered, and the electron affinity of the oxidized species Eox in solution in their most probable state of solvation due to varying interaction with the surrounding electrolyte, a considerable... 

An interesting aspect of molten oxide electrolytes may be mentioned at this point. Some liquids can appear to be solids, i.e., some solids are really liquids of such high... 

Can one explain this importance of the slag Measurements of conductance as a function of temperature and of transport number indicate that the slag is an ionic conductor (liquid electrolyte). In the metal-slag interface, one has the classic situation (Fig. 5.81) of a metal (i.e., iron) in contact with an electrolyte (i.e., the molten oxide electrolyte, slag), with all the attendant possibilities of corrosion of the metal. Corrosion of metals is usually a wasteful process, but here the current-balancing partial electrodic reactions that make up a corrosion situation are indeed the very factors that control the equilibrium of various components (e.g., S ) between slag and metal and hence the properties of the metal, which depend greatly on its trace impurities. For example,... 

Other approaches have focused upon using non-precious metals and their oxides as alternatives to the platinum catalysts. For example, the mixed oxide catalysts of the binary and ternary alloys of noble metals and transition metals have been investigated for the oxygen evolution reaction in solid polymer electrolyte water electrolyzers. Binary, ternary, and quaternary platinum alloys with base metals of Cu, Ni, and Co have been used as electrocatalysts in liquid acid electrolyte cells. It was also reported that a R-Cu-Cr alloy displayed better activity to oxygen reduction than R and Pt-Cr in liquid electrolyte.The enhanced electrocatalytic activity of these types of alloys has been attributed to various factors, including the decrease of the nearest neighbor distance of platinum,the formation of Raney type... 

In a later work, both the CuCl/KCl molten salt Wacker oxidation system and a [Bu4N][SnCl3] system (melting point 60 °C) was applied to the electrocatalytic generation of acetaldehyde from ethanol by co-generation of electricity in a fuel cell [56]. In the cell set-up, porous carbon electrodes supported with an ionic liquid catalyst electrolyte were separated by a proton conducting membrane (Fig. 5.6-4), and current efficiency and product selectivity up to 87% and 83%, respectively, were reported at 90 °C. 

In high-current cells, liquid oxidants are used that simultaneously serve as electrolytes. In Table 11.1, these are systems (1), (2), and (3). 

The oxidant is apart of liquid electrolyte in the cells of the lithium-thionyl chloride and lithium-sulfuryl chloride systems. In the first case, such oxidant electrolyte is the lithium tetrachloroaluminate (LiAlC ) solution in pure thionyl chloride or in thionyl chloride with a sulfur dioxide additive in the second case, it is the solution of the same salt in sulfuryl chloride. 

Benedetti, T. M., V. R. Gonzales, S. I. C. de Torresi, and R. M. Torresi. 2013. In search of an appropriate ionic liquid as electrolyte for macroporous manganese oxide film electrochemistry. Jourrml of Power Sources 239 1-8. 

It can be seen from Figure 21.2.11 that the [C4-mim] cation has a cathodic limit of approximately -2 V versus SCE and that this value is essentially the same for all of the [Cn-mim] cations. Given that the deposition potentials for many metals will fall positive of this potential, it becomes possible to use ionic liquids as electrolytes for metal plating and other similar processes. The broad electrochemical windows (in some cases, over 4 V) indicate that a variety of organic and inorganic electrochemical oxidations and reduction should be possible in ionic liquids. 

Prediction of salt electrochemical stability in the context of Li-ion batteries has mainly involved predicting the Eox of novel lithium salt anions, frequently without any focus on the subsequent decomposition reaction products and mechanisms. However, with recent results on oxidation promoted solvent-anion reactions [57] and the rapid development of solvent-free ionic liquid (IL) electrolytes, investigations of both anion and cation decomposition products are foreseen by us to become more frequent and important - particularly in connection with the passivation phenomena at the negative electrode. As for solvents, we will here follow the historical development of studies and methods, followed by some more recent works that together with our remarks outline our perspective on the future. 

Useful atomic and subatomic scale information on hydroxylated oxide surfaces and their interaction with aggressive ions (e.g., Cl ) can be provided by theoretical chemistry, whose application to corrosion-related issues has been developed in the context of the metal/liquid interfaces [34 9]. The application of ah initio density functional theory (DFT) and other atomistic methods to the problem of passivity breakdown is, however, limited by the complexity of the systems that must include three phases, metal(alloy)/oxide/electrolyte, then-interfaces, electric field, and temperature effects for a realistic description. Besides, the description of the oxide layer must take into account its orientation, the presence of surface defects and bulk point defects, and that of nanostructural defects that are key actors for the reactivity. Nevertheless, these methods can be applied to test mechanistic hypotheses. 

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