Ionic conductivity

About: Ionic conductivity is a(n) research topic. Over the lifetime, 19412 publication(s) have been published within this topic receiving 519167 citation(s).

A lithium superionic conductor

Abstract: Batteries are a key technology in modern society. They are used to power electric and hybrid electric vehicles and to store wind and solar energy in smart grids. Electrochemical devices with high energy and power densities can currently be powered only by batteries with organic liquid electrolytes. However, such batteries require relatively stringent safety precautions, making large-scale systems very complicated and expensive. The application of solid electrolytes is currently limited because they attain practically useful conductivities (10(-2) S cm(-1)) only at 50-80 °C, which is one order of magnitude lower than those of organic liquid electrolytes. Here, we report a lithium superionic conductor, Li(10)GeP(2)S(12) that has a new three-dimensional framework structure. It exhibits an extremely high lithium ionic conductivity of 12 mS cm(-1) at room temperature. This represents the highest conductivity achieved in a solid electrolyte, exceeding even those of liquid organic electrolytes. This new solid-state battery electrolyte has many advantages in terms of device fabrication (facile shaping, patterning and integration), stability (non-volatile), safety (non-explosive) and excellent electrochemical properties (high conductivity and wide potential window).

Solid State Chemistry and its Applications

Abstract: What is Solid State Chemistry? Preparative Methods. Characterization of Inorganic Solids: Application of Physical Techniques. Thermal Analysis. X-ray Diffraction. Point Groups, Space Groups and Crystal Structure. Descriptive Crystal Chemistry. Some Factors Which Influence Crystal Structure. Crystal Defects and Non-Stoichiometry. Solid Solutions. Interpretation of Phase Diagrams. Phase Transitions. Ionic Conductivity and Solid Electrolytes. Electronic Properties and Band Theory: Metals, Semiconductors, Inorganic Solids, Colour. Other Electrical Properties. Magnetic Properties. Optical Properties: Luminescence, Lasers. Glass. Cement and Concrete. Refractories. Organic Solid State Chemistry. Appendixes. Index.

Ionic liquids as electrolytes

Abstract: Salts having a low melting point are liquid at room temperature, or even below, and form a new class of liquids usually called room temperature ionic liquids (RTIL). Information about RTILs can be found in the literature with such key words as: room temperature molten salt, low-temperature molten salt, ambient-temperature molten salt, liquid organic salt or simply ionic liquid. Their physicochemical properties are the same as high temperature ionic liquids, but the practical aspects of their maintenance or handling are different enough to merit a distinction. The class of ionic liquids, based on tetraalkylammonium cation and chloroaluminate anion, has been extensively studied since late 1970s of the XX century, following the works of Osteryoung. Systematic research on the application of chloroaluminate ionic liquids as solvents was performed in 1980s. However, ionic liquids based on aluminium halides are moisture sensitive. During the last decade an increasing number of new ionic liquids have been prepared and used as solvents. The general aim of this paper was to review the physical and chemical properties of RTILs from the point of view of their possible application as electrolytes in electrochemical processes and devices. The following points are discussed: melting and freezing, conductivity, viscosity, temperature dependence of conductivity, transport and transference numbers, electrochemical stability, possible application in aluminium electroplating, lithium batteries and in electrochemical capacitors.

Appraisal of Ce1−yGdyO2−y/2 electrolytes for IT-SOFC operation at 500°C

Abstract: Recent thermodynamic and electrical conductivity data are evaluated to select the most appropriate electrolyte composition for IT-SOFC operation at 500°C. Ce 0.9 Gd 0.1 O 1.95 has an ionic lattice conductivity of 10 −2 S cm −1 at 500°C, and the Gd 3+ ion is the preferred dopant, compared to Sm 3+ and Y 3+ , at this temperature. Thermodynamic investigations indicate that for CeO 2 –Re 2 O 3 solid solutions at intermediate temperatures it becomes easier to reduce Ce 4+ as the concentration of Re 2 O 3 is increased. As the associated electron mobilities do not appear to be a strong function of composition it follows that Ce 0.9 Gd 0.1 O 1.95 has a wider ionic domain than Ce 0.8 Gd 0.2 O 1.9 at intermediate temperatures. Particular attention is drawn to the deleterious effects of impurities (principally SiO 2 ) which are responsible for large dopant concentration dependent grain boundary resistivities. These grain boundary resistivities can obscure the intrinsic lattice ionic conductivities and cause investigators to select non-optimal dopant compositions. It follows that the use of clean (SiO 2 6 O 11 . Finally the I – V characteristics of single cells incorporating 25-μm thick Ce 0.9 Gd 0.1 O 1.95 electrolytes are modelled, and the requirements for composite electrodes briefly discussed so that power densities of 0.4 W cm −2 at 500°C can be attained.

Physicochemical properties and structures of room temperature ionic liquids. 2. Variation of alkyl chain length in imidazolium cation.

Abstract: The alkyl chain length of 1-alkyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([Rmim][(CF3SO2)2N], R = methyl (m), ethyl (e), butyl (b), hexyl (C6), and octyl (C8)) was varied to prepare a series of room-temperature ionic liquids (RTILs), and the thermal behavior, density, viscosity, self-diffusion coefficients of the cation and anion, and ionic conductivity were measured over a wide temperature range. The self-diffusion coefficient, viscosity, ionic conductivity, and molar conductivity change with temperature following the Vogel−Fulcher−Tamman equation, and the density shows a linear decrease. The pulsed-field-gradient spin−echo NMR method reveals a higher self-diffusion coefficient for the cation compared to that for the anion over a wide temperature range, even if the cationic radius is larger than that of the anion. The summation of the cationic and anionic diffusion coefficients for the RTILs follows the order [emim][(CF3SO2)2N] > [mmim][(CF3SO2)2N] > [bmim][(CF3SO2)2N] > [C6mim][(CF3SO2)...