Showing papers in "Solid State Ionics in 2000"

TL;DR: In this article, the authors evaluated thermodynamic and electrical conductivity data to select the most appropriate electrolyte composition for IT-SOFC operation at 500°C and found that the Gd 3+ ion is the preferred dopant, compared to Sm 3+ and Y 3+, at this temperature.

TL;DR: In this article, the physical, chemical, electrochemical and mechanical properties of pure and doped ceria, predominantly in the temperature range from 200 to 1000°C, are investigated.

TL;DR: In this paper, the materials and fabrication methods used for different cell components, and discusses the performance of cells fabricated using these materials; it also discusses materials and processing studies that are under investigation to reduce the cell cost.

TL;DR: In this article, it was shown that the gap between the discharge-charge curves of cells with as-deposited nanocrystalline Li1+xMn2−yO4 cathodes is due to a true hysteresis as opposed to a kinetically hindered relaxation observed with the highly crystalline films.

TL;DR: In this article, a review of the fundamentals of zeolite materials science and their application as catalysts is presented, and the most important parameters which allow the preparation of an almost infinite variety of zeolitic materials tailored for a given catalytic application.

TL;DR: In this article, the potential impact of high densities of interfaces in nanocrystalline solids on ionic conduction and defect formation is examined, and strong support for the notion that the energetics for defect formation may be substantially reduced, leading to markedly increased levels of nonstoichiometry and electronic carrier generation.

TL;DR: In this paper, the extraction and insertion of lithium in solid-state synthesized LiFePO4 has been followed by in situ X-ray diffraction and Mossbauer spectroscopy in "coffee-bag" cells of type Li-metal.

TL;DR: Zr-substituted BaCeO 3 (BaCe 0.9− x Zr x Y 0.1 O 3− α ) was synthesized and its electrical conduction behavior and chemical stability were investigated as discussed by the authors.

TL;DR: Air Products and Chemicals has joined with the U.S. Department of Energy, Ceramatec and other partners to develop, scale-up and commercialize these technologies as discussed by the authors, which could have a significant impact in the global market for distributed oxygen and inert gases.

TL;DR: In this article, different thin-film deposition methods for oxides, especially for stabilized zirconia and compares them with regard to SOFC applications are presented. And each method is described with its special technical features and examples of components for fuel cells are given.

TL;DR: In this article, the poisoning effect of a sulfur-containing impurity on the electrochemical oxidation of H2 has been studied at 1023-1273 K in a gas mixture of H 2 and H 2O at the interface between a Ni-YSZ cermet electrode and a YSZ electrolyte using a complex impedance analysis and a DC polarization method.

TL;DR: In this paper, the oxygen tracer diffusion coefficient and surface exchange coefficient of the materials have been determined by the isotope exchange depth profile method (IEDP), and the compounds La 2 NiO 4+ δ have been prepared with an oxygen excess of up to δ = 0.24.

TL;DR: In this paper, a series of exposure tests was carried out with anode substrates used in SOFC development at the Research Centre Julich, where the changes in electrical conductivity as well as in the microstructure of the material were investigated.

TL;DR: In this paper, the authors examined activation and concentration polarization effects in anode-supported solid oxide fuel cells (SOFCs), where the anode and the cathode consisted respectively of porous, composite, contiguous mixtures of Ni+yttria-stabilized zirconia (YSZ) and Sr-doped LaMnO 3 (LSM)+YSZ.

TL;DR: In this paper, the crystal structure and morphology of nanosized Si particles and wires after Li-insertion/extraction electrochemically have been studied by ex-situ XRD, Raman spectroscopy and electronic microscopy.

TL;DR: In this paper, the performance of perovskites based on alkaline-earth containing lanthanum cobaltites was investigated in the system La1−xSrxCo1−yFeyO3−δ.

TL;DR: In this paper, the structure of Zr-Ti solid solutions was investigated at temperatures in the range 20-1500°C and the structure remained fully ordered over this temperature range.

TL;DR: In this paper, the role of dopant-vacancy interactions in influencing the concentration of mobile vacancies is assessed for selected materials, and the results from atomistic lattice simulations lead to the following conclusions.

TL;DR: In this paper, a personal view is presented of developments over the period 1964-1999 that have gradually made possible the fabrication of IT-SOFC stacks operating at 500°C.

TL;DR: In this article, a defect model is proposed to rationalize the (3+ d ) vs. log log P (O 2 ) relationship as well as the reported electronic properties between the two plateaus, which is based on the following assumptions.

TL;DR: In this article, the proton transport mechanisms in systems containing water and in cubic perovskite-type oxides are analyzed in detail in terms of chemical interactions, which allow for high rates of proton transfer and structural reorganization.

TL;DR: Li 2 GeS 3, Li 4 GeS 4, Li 2 ZnGeS 4, Li 4−2 x Zn x GeS4, Li 5 GaS 4 and Li 4+ x + δ (Ge 1− δ ′− x Ga x )S 4 showed the highest conductivity of 6.5×10 −5 S−cm −1 at room temperature as mentioned in this paper.

TL;DR: In this article, the effect of small amounts (0.8 Gd 0.2 O 2−x powder with an average crystallite size of 20 nm) of transition metal oxide doping below 2 mol.

TL;DR: In this paper, the results of studies of the preparation, structure and electrical conductivity of ZrO 2 :16% Y and CeO 2 thin films are presented, with grain size controlled in the region of 1-400 nm.

TL;DR: In this article, the thermal expansion coefficients of Gd-doped ceria and reduced ceria were measured in the range from 100 to 873 K and those of reduced Ceria were calculated theoretically and they were in good agreement with experimental ones except for the higher temperature range.

TL;DR: In this paper, the biaxial flexural strength and fracture toughness of tape-cast YSZ have been measured at room temperature and at a typical operating temperature of 900°C.

TL;DR: In this paper, atomistic simulation calculations based on energy minimization techniques have been used to study the energetics associated with M2O3 solution in ZrO2.

TL;DR: In this article, the authors evaluated BaZr0.9Y0.1O2.95 prepared at very high sintering temperatures as to whether it displayed the high water vapor solubility claimed in recent work.

TL;DR: In this article, the authors investigated the performance of several compositions in the scandia-zirconia system (Sc 2 O 3 content between 7.0 and 11.0 mol%) as a function of temperature and time at the nominal solid oxide fuel cell operating temperature of 850°C.