Showing papers on "Ionic conductivity published in 1990"
TL;DR: In this article, solid electrolytes based on lithium titanium phosphate were prepared, and their phase, porosity of the sintered pellets, and electrical conductivity were studied, and the porosity decreased greatly by partially replacing Ti4+ and P5+ in with M3+ and Si4+ions.
Abstract: Solid electrolytes based on lithium titanium phosphate were prepared, and their phase, porosity of the sintered pellets, and electrical conductivity were studied. The conductivity was increased and the porosity decreased greatly by partially replacing Ti4+ and P5+ in with M3+ and Si4+ions, respectively. The maximum conductivity at 298 K is for . The conductivity was considerably increased by the mixing of binders such as or with . The main reason for the conductivity enhancement of these electrolytes seems to be attributable to the increase of the sintered pellet density with the enhancement of the lithium concentration at the grain boundaries.
720 citations
TL;DR: In this article, the authors explored the oxide-ion conductivity in oxygen-deficient perovskites with Brownmillerite and showed that Ba2In2O5 exhibits a low extrinsic O2-ionconductivity below 650°C, an intrinsic conductivity across an ordering energy gap △Hg that decreases with increasing temperature in the interval 650-C
325 citations
257 citations
TL;DR: In this article, a solution-cast polyethylene oxide (PEO) complexed with ammonium perchlorate (NH4ClO4) has been established using optical microscopy, XRD, DTA, IR, coulometry, transient ionic current and electrical conductivity studies.
Abstract: Proton transport in solution-cast films of polyethylene oxide (PEO) complexed with ammonium perchlorate (NH4ClO4) has been established using optical microscopy, XRD, DTA, IR, coulometry, transient ionic current and electrical conductivity studies. The solubility of NH4ClO4 in PEO is found to be limited to a maximum concentration NH4+/EO ratio of 0.167. The highest conductivity ( approximately 1.05*10-5 S cm-1) is for the film with NH4+/EO=0.02-0.1. The H+ ion transference number, tH+, and mobility, mu H+, are 0.85 and 1.7*10-4 cm2 V-1 s-1, respectively. The movement of ClO4- ions also contributes slightly to the overall charge transport.
217 citations
TL;DR: In this article, Li1+xMxTi2−x(PO4)3 systems with various metal ions of M3+ (M=Al, Cr, Ga, Fe, Sc, In, Lu, Y, or La) were prepared, and their properties were investigated.
196 citations
01 Jan 1990
TL;DR: In this paper, the authors present a Monte Carlo simulation of diffusion in solids, showing a correlation between the high temperature behaviour of highly concentrated solid solutions in stationary creep and in diffusion possible.
Abstract: Introductory lecture.- I - Diffusion Theory.- Thermally activated processes in solids.- Atomic theory of diffusion-linear response theory.- Diffusion in alloys.- Non linear phenomena in solid state diffusion.- Diffusion in heterogeneous materials.- II - Point Defect Parameters Diffusion Coefficients.- Evaluation of diffusion coefficients.- Calculation of point defect parameters in ionic materials.- Monte Carlo simulation of diffusion in solids: Some recent developments.- Experimental techniques for the measurement of diffusion coefficients.- Diffusion and soft phonons in bcc metals.- Vacancy-mediated interstitial-substitutional diffusion in semiconducting and metallic matrices.- III - Diffusion in Short Circuits and Under Irradiation.- Surface diffusion on metals (abstract).- Dislocation and grain boundary diffusion.- Interdiffusion in thin films (abstract).- Diffusion and precipitation under irradiation.- IV - Diffusion in Ceramics (Oxides, Carbides, Nitrides).- Defects and diffusion in oxides.- Diffusion in high-Tc superconductors.- Analysis of oxygen diffusion in superconducting YBa2Cu307-? ceramic oxides.- Diffusion in carbides and nitrides.- V - Diffusion in Ionic Solids.- Diffusion in ionic solids.- Surface and dislocation effects on diffusion in ionic crystals.- The ionic hall effect in crystals.- Diffusion in fast -ion conductors.- Diffusion in geomaterials (abstract).- VI - Diffusion in Semiconductors.- Atomic diffusion in homopolar semiconductors (abstract).- Diffusion of dopants in silicon.- Diffusion in compound semiconductors.- Experimental studies of hydrogen motion in hydrogenated amorphous silicon and germanium.- VII - Diffusion in Non Crystalline Materials.- Diffusion in conducting polymers.- Diffusion in amorphous materials.- Amorphization by solid state reaction.- APPENDIX Posters-abstracts.- Related to Chapter I.- S. Malik A. V. Chadwick Oxidation in a temperature gradient.- S. A. Akbar Atomistic treatment of demixing in multicomponent oxides.- S. A. Akbar The path probability method: An atomistic technique in diffusion.- Related to Chapter II.- C. Lexcellent G. Some J. Bernardini S. Benlemlih Is a correlation between the high temperature behaviour of highly concentrated solid solutions in stationary creep and in diffusion possible?.- P. W. M. Jacobs M. L. Vernon Defect energies for magnesium oxide and lithium oxide.- S.-Q. Shi D. A. Thompson W. W. Smeltzer M. P. Riehm Deuterium permeation behavior in polycristalline nickel implanted with nickel and helium ions.- C. Maunier and V. Pontikis Intergranular superionic conductivity in bicrystals of the fluorite structure.- A. Menai, M. Kherraz, J. Bernardini and Moya Determination of diffusion coefficients in presence of precipitation of the diffusing atoms in alloys.- J. Fischer and P. Jung Diffusion inferritic FeAlNiNb studied by NiAl-precipitate coarsening.- J. Grammatikakis, K. Eftaxias, V. Hadjicontis and V. Katsika Interconnection of the diffusion coefficients of various elements in aluminium.- T.D. Andreadis and M. Rosen Defect concentration dependent migration energies and defect diffusion in irradiated AgZn alloys.- Related to Chapter III.- A.M. Brass, A. Chanfreau and J. Chene Are grain boundaries short-diffusion paths for hydrogen diffusion in high purity nickel?.- I.A. Szabo, D.L. Beke and F.J. Kedves On the transition between the C-and B-kinetic regimes for grain-boundary diffusion.- R. Scholz Blank profiles in tracer diffusion under irradiation.- Related to Chapter IV.- D. Prot, M. Miloche and C. Monty Oxygen self-diffusion in aluminium oxide single crystals.- U. Littmark and H.C. Paulini Carbide formation during post annealing of a-c:D coated molybdenum.- Related to Chapter V.- S.K. Wonnell and L.M. Slifkin Measurement of the ionic space charge potential and defect formation parameters in AgBr.- T.S. Bush, A.V. Chadwick, M. Cole and C.R.A. Catlow Ionic conductivity and local structure of lanthanide ??-alumina.- S.R. Elliott Non-debye relaxation in ionically-conducting glasses.- W. Soppe Ionic conductivity of borate glasses.- K. Stanley, B. Finkernagel and A. Laskar Selenium ion diffusion in silver halides.- Related to Chapter VI.- C.A. Londos Diffusivities and solubilities of various elements in silicon.- S. Mitra and J. Shinar Long range atomic H motion in p-doped rf-sputter deposited a-Si:H.- M. Backhaus-Ricoult Role of diffusion in solid state reactions between SiC and (Fe, Ni) alloys.- L.H. Allen, D. Theodore and J.W. Mayer Si crystal growth in the Au and poly Si system during thermal anneal.- I. Delidais, P. Maugis, D. Ballutaud and J.L. Maurice Hydrogenation and oxidation of p-type silicon.- A. Chari, P. De Mierry, D. Ballutaud and M. Aucouturier Introduction and diffusion of hydrogen in silicon.- Related to Chapter VII.- E. Gaffet, N. Merk and G. Martin Crystal to amorphous phase transition induced by ball milling in Ni-Zr alloys.- J.C. Mesquita and L.M. Abrantes Polypyrrole - counter ions motion and the diffusion model.- D. Jacobs and H. Nakanishi Correlation functions and the diffusion coefficient for random hopping models.- J.C. Dyre AC properties of disordered ionic conductors.- V. Dupuis, M.F. Ravet, C. Tete and M. Piecuch Stability of multilayers for X-ray optics under pulsed laser heating.
115 citations
TL;DR: In this paper, a glass processing method that employs a carbon-coated quartz container was used to study the B2S3 containing glasses, which resulted in transparent glasses with a high Li2S content.
104 citations
TL;DR: In this paper, it was shown that the conductivity of tetra-alkylammonium salts in low dielectric constant media is not greatly affected by the length of the carbon chain of the cation.
Abstract: It is shown that the conductivity of tetra-alkylammonium salts in low dielectric constant media is not greatly affected by the length of the carbon chain of the cation. The effect upon the conductivity of varying the size of anions and cations has been analysed in several pure and mixed solvents using a modified Fuoss–Kraus theory to take into account the activity coefficient of the undissociated electrolyte. The interionic distance parameter of the ion pairs is calculated and shown to be fairly constant, indicating interpenetration of the ions. Also, following on from the preceding paper, the effect upon the conductivity of the local environment around the solute is found to be negligible. The bulk dielectric constant of the solvent is shown to be the major factor affecting the conductivity of salts.
95 citations
TL;DR: In this article, the Anderson-Stuart model was extended to describe the ac conductivity based on a thermally activated hopping charge process and the theoretical results obtained are analysed and compared with previous experimental data.
Abstract: A new conductivity model for ionically conducting materials is proposed. For the first time, the Anderson-Stuart model, originally developed to account for the dc conductivity activation energy in silicate glasses, is extended to describe the ac conductivity based on a thermally activated hopping charge process. The theoretical results obtained are analysed and compared with previous experimental data. Despite the paucity of and variation in the experimental results, the present model is not inconsistent with these data and, therefore, may be a new and interesting approach to understand the ac conductivity behaviour of ionic conductors.
85 citations
TL;DR: In this paper, the structure factors with which electrons are connected are expressed symmetrically in terms of the structure factor of ions in the long wavelength limit using the fluctuation-dissipation theorem and the Kramers-Kronig relation.
84 citations
TL;DR: In this paper, the ac impedance of poly-(1-methyl-3-(pyrrol-1-ylmethyl)pyridinium]+(poly-MPMP+) as a function of potential has been investigated in acetonitrile solutions.
Abstract: The ac impedance of poly-[1-methyl-3-(pyrrol-1-ylmethyl)pyridinium]+(poly-MPMP+) as a function of potential has been investigated in acetonitrile solutions. When the polymer is reduced it acts merely as a barrier to the migration of ions to the double layer of the underlying electrode. Thus the ionic conductivity of the reduced polymer can be obtained. This conductivity is not dependent on the concentration of the electrolyte in the bulk solution, indicating that there is little contribution from non-exchange electrolyte in the film. Oxidized poly-MPMP+ behaves as a finite transmission line with two resistance rails. One rail corresponds to the film's ionic resistance, which is virtually independent of potential. The other rail represents the film's electronic resistance, which increases as the potential of the film is decreased. Analysis of Nyquist plots allows determination of both of these resistances as well as the film's Faradaic capacitance. Quantitative results are compared with results from chronoamperometry and rotating-disc voltammetry.
TL;DR: In this paper, two different methods leading to the preparation of highly conductive polymer solid electrolytes are described, where polymers were modified by the addition of ceramic powders or organic polymers used as crystallization retarders.
TL;DR: In this article, two pyrrole monomers substituted at the nitrogen atom by appropriate alkyl ammonium chains were electropolymerized in acetonitrile onto electrode surfaces.
TL;DR: LiTi2(PO4)3-lithium salt systems have been investigated in order to obtain a high lithium ion conductor in this paper, where the salts acted as binder for sintering.
Abstract: LiTi2(PO4)3-lithium salt systems have been investigated in order to obtain a high lithium ion conductor. The salts acted as binder for sintering. The porosity decreased considerably and the conductivity of the pellets increased by the binder utilization. The maximum conductivity was 3 × 10−4 S·cm−1 for the LiTi2(PO4)3–0.2Li3BO3 system. The mixed binder was found to exist as a glassy or a thin coating second phase.
TL;DR: In this article, the grain-boundary and lattice resistivity in Y-TZP materials are analyzed using a four-probe dc conductivity measurements, scanning and transmission electron microscopy, x-ray photoelectron spectroscopy, and xray diffraction.
Abstract: Both the grain-boundary and the lattice resistivity in Y-TZP materials is affected by several ceramic processing variables. These include, sintering temperature, sintering time, cooling rate from high temperatures (>1000°C), post-sinter heat treatments, the level and types of impurities and the spatial distribution of Y2O3 in the starting powders. Because of the inherent large grain-boundary surface area the grain-boundary resistivity in these ceramics is extremely sensitive to the presence and location of glassy impurities. Impedance spectroscopy has been used along with four-probe dc conductivity measurements, scanning and transmission electron microscopy, x-ray photoelectron spectroscopy and x-ray diffraction to understand the grain-boundary and lattice resistivity behaviour in Y-TZP ceramics as a function of various ceramic processing variables.
TL;DR: In this article, a mixed mass-transport and kinetic control of sodium ion reduction at porous inert electrodes on sodium beta-double-prime alumina solid electrolyte (BASE) ceramic in a high-temperature electrochemical cell has been observed and modeled.
Abstract: Mixed mass-transport and kinetic control of sodium ion reduction at porous inert electrodes on sodium beta-double-prime alumina solid electrolyte (BASE) ceramic in a high-temperature electrochemical cell has been observed and modeled. The high ionic conductivity of BASE and the reversibility of the liquid sodium/BASE anodic half-cell led to assignment of potential-dependent (nonohmic) resistances to kinetic and mass-transport processes associated with the porous electrode. The morphology of these electrodes and typical sodium gas pressures are consistent with Knudsen, or free-molecular, flow through the electrode.
TL;DR: The existence and ionic conductivity of Na3ln2(PO4)3 with Nasicon-like structure have been investigated and the results compared with literature data as mentioned in this paper.
Abstract: The existence and ionic conductivity of solid solutions Na1+xM
x
III
Zr2−x(PO4)3 with Nasicon-like structure have been investigated and the results compared with literature data. A limited range of solid solutions is formed with MIII = aluminium, gallium, yttrium, ytterbium, whereas a continuous series is obtained for MIII = chromium, iron, scandium, indium. The pure end member Na3ln2(PO4)3 is reported for the first time; according to powder diffraction data, it is hexagonal witha = 0.8966(1) andc = 2.2104(4) nm. The small monoclinic distortion already known for MIII = chromium, iron and scandium is restricted tox values very close to 2. Ionic conductivity measurements show that for a given value ofx, the mobility of the Na+ ions is strongly influenced both by the ionic radius and the type of electronic structure of the MIII ion. However, no simple correlation can be found.
TL;DR: The development of all-solid-state rechargeable batteries has been a hot topic in the last few decades as discussed by the authors, due to their inherent advantages of negligible self-discharge, long cycle life, high reliability, and virtual absence of container corrosion.
Abstract: The dramatic proliferation of products based on semiconductor technology is a strong testament to the predictability and reliability of solid-state technology. In a similar vein, advances in materials exhibiting high levels of ionic conduction in the solid state has led to worldwide efforts in the development of all-solid-state rechargeable batteries. Although higher current densities are achievable with liquid electrolytes, all-solid-state cells offer inherent advantages of negligible self-discharge, long cycle life, high reliability, and virtual absence of container corrosion. Elegant work on polycrystalline and vitreous electrolytes has led to solid electrolytes with suitable ionic conductivities for battery development,1,2,3 however, the superior mechanical properties of elastomeric electrolytes combined with the simplicity of fabrication of thin separator films from these materials, has led to very active pursuit of solid-state cells based on solid polymeric electrolytes (SPE's). Although so...
Abstract: This paper examines the phenomenon of electromechanical failure of zirconia. It is shown that spatial variation of electronic conductivity in a predominantly oxygen ion conductor can lead to internal precipitation of molecular oxygen and its pressurization. Internal pressures high enough to crack zirconia can develop if the electronic conductivity is higher on the oxygen exit side. The calculations demonstrate that the kinetics of pressurization are very sensitive to the relative magnitudes of the electronic and the ionic conductivities. Oxygen was electrolyzed at 800{degrees}C through zirconia solid electrolytes with lanthanum strontium manganate (LSM) electrodes under an applied dc potential of 1.0 V. Spalling of the solid electrolytes was observed. Composite disk electrolytes were fabricated such that part of the disk contained TiO{sub 2} as a dopant which was added to enhance the electronic conductivity. The electrolytes exhibited severe cracking and pitting when the TiO{sub 2}-doped region was on the oxygen exit side. No degradation occurred when the TiO{sub 2}-doped region was on the oxygen entry side. Implications regarding the use of mixed conductors as dense electrodes in electrochemical systems are discussed.
TL;DR: In this paper, electric conductivity, oxides in conductivity and oxide ion vacancy were measured from room temperqatrure to 900°C and in a reducible gas atmosphere, mainly 10 ppm CO to inverse how the oxides ion vacancy effects the electric-ionic conduction.
TL;DR: In this article, single phase lithium phosphorus nitrides Li 7 NP 2 and LiN P 2 were prepared by reaction of the binary n-bromide P 3 N 5 and Li 3 N at 620 and 800°C, respectively.
TL;DR: In this article, the electrical and electrochemical properties of thin films of polyethylene oxide electrolytes with and without 12-crown-4 ether (12Cr4) were studied as a function of temperature and in the frequency regime from 100 kHz to 0.1 Hz.
Abstract: The electrical and electrochemical properties of thin films of polyethylene oxide electrolytes with and without 12-crown-4 ether (12Cr4) are studied as a function of temperature and in the frequency regime from 100 kHz to 0.1 Hz. These measurements were made on electrolytes containing LiCF3SO3, LiBF4, or LiClO4 salts. At a given temperature, the bulk conductivity for a particular salt depends on the 12Cr4 concentration, reaching a maximum for a ratio of 12Cr4 to Li of 0.003.
TL;DR: Amorphous compounds of formula LiTixZr2−x(PO4)3, with x ranging from 0.25 to 2, have been prepared in aqueous media and crystallized at 900°C as mentioned in this paper.
TL;DR: In this article, the authors determined the temperature dependence of the ionic transport numbers of Li + by means of the combination of the complex impedance and potentiostatic polarization measurements of the crosslinked poly(ethylene oxide) (PEO) electrolytes containing dissolved lithium perchlorate (LiClO 4 ).
TL;DR: In this article, the average jump times for the cationic self-diffusion were derived from T1 and T1ρ data to be 5 × 10-3 s at room temperature and 3 × 10−7 s at Tm.
Abstract: Butylammonium chloride crystals annealed by slowly scanning through the phase transitions many times have been shown to exhibit a simple thermogram, having a single phase transition at 241 K (Ttr) on heating from ca. 100 K up to the melting temperature Tm(487 K). Another additional thermal treatment was made on the annealed crystals, then measurements of 1H NMR spin–lattice relaxation times T1, T1ρ and the second moment M2 were measured over the same temperature range. These results showed that the cationic axial reorientation mainly contributes to 1H T1 around room temperature, while the cationic self-diffusion plays an important role in the high-temperature range near Tm. AC electrical conductivity measurements on single crystals revealed that ionic conduction takes place in the 2D layers of the room-temperature phase (rotator phase) which have a lamellar-type double-layer structure. The observed T1 and T1ρ data were explained well by applying the theory of 2D diffusion by MacGillivray and Sholl in the low vacancy concentration limit. The average jump times for the cationic self-diffusion were derived from T1 and T1ρ data to be 5 × 10–3 s at room temperature and 3 × 10–7 s at Tm. The transition entropies at Ttr and Tm determined by differential scanning calorimetry were 26 and 19 J K–1 mol–1, respectively. These results imply that the rotator phase is a kind of plastic crystal.
TL;DR: In this paper, solid electrolytes based on lithium titanium phosphate were prepared, and their phase, porosity of the sintered pellets, and electrical conductivity were studied, and the porosity decreased greatly by partially replacing Ti4+ and P5+ in with M3+ and Si4+ions.
Abstract: Solid electrolytes based on lithium titanium phosphate were prepared, and their phase, porosity of the sintered pellets, and electrical conductivity were studied. The conductivity was increased and the porosity decreased greatly by partially replacing Ti4+ and P5+ in with M3+ and Si4+ions, respectively. The maximum conductivity at 298 K is for . The conductivity was considerably increased by the mixing of binders such as or with . The main reason for the conductivity enhancement of these electrolytes seems to be attributable to the increase of the sintered pellet density with the enhancement of the lithium concentration at the grain boundaries.
TL;DR: In this paper, the properties of composite polymer electrolytes formed by adding inert ceramic fillers to the standard poly(ethylene oxide)-lithium salt complexes are illustrated in terms of ionic conductivity and of mechanical properties.
TL;DR: In this paper, the authors investigated the structure, electrical conductivity and oxygen ion transport number of solid solutions in the ternary system ZrO 2 −CeO 2 -Y 2 O 3, and found that electrical conduction proceeds by transport of oxygen ions through the network of oxygen vacancies in the lattice.
Abstract: Solid solutions in the ternary system ZrO 2 -CeO 2 -Y 2 O 3 , by virtue of their high-temperature stability and good electrical conductivity, have potential application in many advanced technologies such as the magnetohydrodynamic (MHD) generator. The investigations reported here include studies on the structure, electrical conductivity and oxygen ion transport number of solid solutions in the system 0·9{(ZrO 2 ) 1 − x -(CeO 2 ) x }-0·1(Y 2 O 3 ) in the temperature range 1000–1600 K in static air. It is found that electrical conduction proceeds by transport of oxygen ions through the network of oxygen vacancies in the lattice. The variation of conductivity with composition has been analysed in relation to the changes in lattice parameter and scattering of oxygen ions.
TL;DR: In this article, two different distributions of lithium are proposed: one in which Li+ ions are dispersed in Li2OTeO2 glasses and another one, where Li+ and F− ions are associated in the network of LiF ǫ-TeO 2 glasses.
Abstract: TeO2 forms stable glasses with Li2O and LiF in a large range of compositions (from 0.45 to 0.9 in molar ratio of TeO2). The ionic conductivity of these glasses is measured as a function of temperature and chemical composition by the complex impedance method (frequency range: 10−2 −104 Hz, temperature range: 100°C−Tg_. A parallel study by 7Li- and 19F-NMR spectroscopy allows identification of Li+ ions as the carriers responsible for the ionic conductivity of these solids. From the second moment of NMR signals, two different distributions of lithium are proposed: one in which Li+ ions are dispersed in Li2OTeO2 glasses and another one, in which Li+ and F− ions are associated in the network of LiFTeO2 glasses. These distributions are correlated with ionic conductivity results.