Salt hydrates as latent heat storage materials:Thermophysical properties and costs

Inorganic and organic "solvent-in-salt" (SIS) systems have been known for decades but have attracted significant attention only recently. Molten salt hydrates/solvates have been successfully employed as non-flammable, benign electrolytes in rechargeable lithium-ion batteries leading to a revolution in battery development and design. SIS with organic components (for example, ionic liquids containing small amounts of water) demonstrate remarkable thermal stability and tunability, and present a class of admittedly safer electrolytes, in comparison with traditional organic solvents. Water molecules tend to form nano- and microstructures (droplets and channel networks) in ionic media impacting their heterogeneity. Such microscale domains can be employed as microreactors for chemical and enzymatic synthesis. In this review, we address known SIS systems and discuss their composition, structure, properties and dynamics. Special attention is paid to the current and potential applications of inorganic and organic SIS systems in energy research, chemistry and biochemistry. A separate section of this review is dedicated to experimental methods of SIS investigation, which is crucial for the development of this field.

"Solvent-in-salt" systems for design of new materials in chemistry, biology and energy research.

Solid–liquid phase equilibrium in the systems of LiBr–H2O and LiCl–H2O

The conductances, densities, and viscosities of aqueous solutions of lithium chlorate have been obtained over the complete range of concentration at 1318 °C and up to saturation (and somewhat beyond) at 2500 °C The curve of specific conductance versus concentration passes through a maximum which does not shift noticeably in composition with change in temperature There are no minima on the curves of equivalent conductance versus concentration The relative viscosity of the solutions decreases with rise in temperature; this is the reverse of the effect usually observedThe experimental results have been compared with the calculated results, obtained by the use of the equations of Wishaw and Stokes and of Falkenhagen

The conductances of aqueous solutions of lithium chlorate at 25.00 °c. and at 131.8 °c.

Raman spectra of sodium chlorate in N,N-dimethylformamide (DMF) solution were obtained. The band at 926 cm−1 that has been previously assigned to the vibrational mode of the associated chlorate with Cs symmetry is, in fact, due to the non-associated chlorate vibration with C3v symmetry. In the ν2 region of the chlorate anion, a new feature at 600 cm−1 was observed and the results show that it also belongs to the non-associated chlorate. Both bands at 926 and 600 cm−1 are assigned to the vibrations involving O37ClO, in full agreement with the results of normal coordinate analysis reported by others workers. Quantitative measurements performed in the range 590–630 cm−1, allowed the determination of the extent of contact ion pair formation. The results show that the ion association in the NaClO3–DMF system is significantly greater than in the NaClO4–DMF system and this is due the higher charge density and lower symmetry of the chlorate anion. Similar conclusions were reached by others who used different experimental techniques. Copyright © 2004 John Wiley & Sons, Ltd.

Contact ion pairs: a quantitative Raman study of the NaClO3–DMF system

The equilibrium diagram of the system lithium chlorate – water has been determined at all temperatures and that of the system lithium chlorate – lithium chloride – water at the temperatures 3.0°, 6...

A. N. Campbell

Papers

The system lithium chlorate – lithium chloride – water at various temperatures