Glassy Solid Electrolytes Research Articles

New superionic glasses based on silver iodide with organic monomer ions

In this paper, a new type glassy solid electrolyte is reported, which is based on silver iodide with monomer organic ions. Glass preparations were tried by rapidly quenching the melts of the silver iodide (AgI), tetraethylammonium iodide (TEAI), tetramethyl-ammonium iodide (TMAI) and CsI systems. The glass formations were confirmed by X-ray diffraction, DSC and polarized microscope. Glass forming regions were discovered in the system of AgI-TMAI-TEAI and AgI-TMAI-CsI. The ionic conductivity values of those glasses are in order of 10 −2 ohms −1 cm −1 a room temperature. These new glasses exhibit high ionic conductivity comparable to the oxide based superionic glasses, and 10 to 10000 times larger than those of typical Li + conducting polymer electrolytes.

Ni-implanted vitreous electrolyte AgAsS 2: ECR, ionic and electronic conductivity

Transport properties of AgAsS 2 glassy solid electrolyte implanted with 60 keV nickel ions at dose of 10 17 Ni/cm 2 were studied. The increase of ionic conductivity by 2.5 orders of magnitude and simultaneous activation energy decrease from 0.34 to 0.18 eV have been observed. The ionic conductivity enhancement is related to two-phase morphology of implanted layer which leads to formation of “infinite” perculation cluster with low-energy barriers for Ag + ion motion. AgAsS 2 glass reveals p-type electronic conductivity, σ p . Nickel ion implantation increases σ p by six orders of magnitude. The enhancement of hole transport has been explained involving small-polaron hopping between Ni 2+ and Ni 3+ ions. Temperature dependence of Ni 3+ ESR line intensity is in agreement with polaron mechanism of σ p in Ni-containing chalcogenide glasses. ESR results showed also that charge state and coordination of impurity nickel ions in Ni-implanted and thermally-doped AgAsS 2 glasses are identical.

Electrical and acoustical relaxation in fast ionic conductors

The ultrasonic velocity, attenuation coefficient, electric conductivity and dielectric permittivity have been measured in wide temperature and frequency ranges in various crystalline, polycrystalline and glassy solid electrolytes. The high relaxational ultrasonic attenuation maxima and corresponding velocity dispersion have been observed. Such behaviour is supposed to be determined by acoustoionic interactions of two types: (i) the piezoelectric in the piezoelectric superionic; (ii) interaction caused by acoustic wave modulation of chemical potential felt by mobile ions in the centrosymmetric materials. In polycrystalline and glassy superionics the non-Debye behaviour for ultrasonic relaxation has been established. In such materials the characteristic frequency dependencies of ionic conductivity and dielectric permittivity were obtained. A simple theoretical model describing both frequency and temperature dependencies of electrical and acoustical properties of solid electrolytes is proposed. This model is based on continuous distribution of activation energies in a limited interval and describes the experimental data fairly well.

Electrochemical measurement of the diffusion coefficient of silver in thin films of V 2O 5P 2O 5 glass

Thin film of V 2O 5P 2O 5 glass were made by vacuum evaporation. These layers have a molar composition 45V 2O 5− 55P 2O 5; their electronic conductivity at room temperature is about 10 −7 Ω −1 cm −1 ( E σ= 0.43 eV) . An electrochemical cell with glassy solid electrolyte, Ag/Ag + conductive glass/thin V 2O 5−P 2O 5 was used to measure the diffusion coefficient of silver, D Ag in these layers. Measurements at different temperatures lead to a value D Ag = D 0 exp. − E D RT where D 0 = 5.5 · 10 −1 cm 2/s, E D = 0.88 eV. At room temperature, D Ag is small and has an approximative value of 10 −15 cm 2 ·s −1.

Versatile organic iodide melts and glasses with high mole fractions of LiI: Glass transition temperatures and electrical conductivities

Noting the high σ o of LiI + LiPS 3 glasses we have explored the properties of salt melts in which all anions are iodide. To obtain these, various low-melting tetraalkylammonium iodides, TAAI's, which may vitrify with up to 70 mo1% LiI, have been synthesized. Some mixtures may remain liquid at room temperature indefinitely. Electrical conductances do not attain the room temperature values of the inorganic LiI glasses though may reach −10 −3 S cm −1 at 100°C. The organic cations introduce many possibilities for structural manipulation, and may also be polymerized. Preliminary polymerization and conductivity results are reported. The investigation has suggested an important principle (the counter-polarization principle) distinguishing high alkali conductivity in salt or polymer solutions on the one hand and glassy solid electrolytes on the other.

Mechanisms of ionic conduction in glassy solid electrolytes

We discuss the microscopic origin of the anomalous specific heat and of the low-frequency (10 2–10 6 Hz) ionic conductivity in glassy (and normal) solid electrolytes. The relation between the conductivity and the configurational excitations that give rise to specific-heat anomalies at low temperature is analyzed. We also point out to which extent the present conclusions can be extended to disordered systems in general.

Comparison of Ionic Conductivity Between Glassy and Crystalline Solid Electrolytes in the System AgI‐Ag2O‐MoO3

Comparison of Ionic Conductivity Between Glassy and Crystalline Solid Electrolytes in the System AgI‐Ag₂O‐MoO₃