Characterization of New Ionically Conducting Peo-Based Networks by Diffusion, Elasticity Modulus and Ionic Conductivity Measurements

1992 ◽  
Vol 293 ◽  
Author(s):  
Herve Cheradame ◽  
F. Desbat ◽  
P. Mercier-Niddam ◽  
S. Boileau
Keyword(s):  
Diffusion Coefficient ◽  
Ionic Conductivity ◽  
Elasticity Modulus ◽  
Sol Gel ◽  
Cation Transport ◽  
Lithium Cation ◽  
Conductivity Measurements ◽  
Conducting Materials ◽  
Diffusion Studies

AbstractIonically conducting materials containing PEO were prepared from telechelic di(methyl-diethoxy-silane) PEO, synthesized by the hydrosilylation of telechelic diallyl-PEO with methyldiethoxysilane. The network is obtained by the usual sol-gel chemistry. Then, it is filled with LiClO4 by diffusion of the salt and further drying. A comparison is made with the same kind of materials crosslinked using urethane chemistry. Diffusion studies show that the diffusion coefficient of solvent is similar for both types of materials, whilst the ionic conductivity is higher for the networks crosslinked with siloxane bonds. An experiment of diffusion of LiClO4 without solvent showed that this salt has a diffusion coefficient of the order of 2.10-8 cm2.sec-1 at 34°C. The conductivity calculated from this determination is compatible with the mechanism of lithium cation transport by the diffusion of salt molecules. Elasticity modulus measurements show that the salt aggregates are essentially located within the crosslinks at low concentration, but also in the PEO chains for salt concentrations higher than 1 mol/l.

Ionic conductivity in nanocrystalline Gd doped ceria

2008 ◽  
Vol 1122 ◽  
Author(s):  
Gianguido Baldinozzi ◽  
David Simeone ◽  
Dominique Gosset ◽  
Mickael Dollé ◽  
Georgette Petot-Ervas
Keyword(s):  
Grain Size ◽  
Ionic Conductivity ◽  
Sol Gel ◽  
Doped Ceria ◽  
Narrow Size Distribution ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes ◽  
The Impact

AbstractWe have synthesized Gd-doped ceria polycrystalline samples (5, 10, 15 %mol), having relative densities exceeding 95% and grain sizes between 30 and 160 nm after axial hot pressing (750 °C, 250 MPa). The samples were prepared by sintering nanopowders obtained by sol-gel chemistry methods having a very narrow size distribution centered at about 16 nm. SEM and X-ray diffraction were performed to characterize the sample microstructures and to assess their structures. We report ionic conductivity measurements using impedance spectroscopy. It is important to investigate the properties of these systems with sub-micrometric grains and as a function of their composition. Therefore, samples having micrometric and nanometric grain sizes (and different Gd content) were studied. Evidence of Gd segregation near the grain boundaries is given and the impact on the ionic conductivity, as a function of the grain size and Gd composition, is discussed and compared to microcrystalline samples.

Sol-Gel Non-hydrolytic Synthesis of a Nanocomposite Electrolyte for Application in Lithium-ion Devices

2004 ◽  
Vol 822 ◽  
Author(s):  
Flávio L. Souza ◽  
Paulo R. Bueno ◽  
Ronaldo C. Faria ◽  
Elson Longo ◽  
Edson R. Leite
Keyword(s):  
Ionic Conductivity ◽  
Room Temperature ◽  
Sol Gel ◽  
Specific Treatment ◽  
Lithium Ion ◽  
Polymeric Chain ◽  
Conductivity Measurements ◽  
Ion Conductor ◽  
Nanocomposite Electrolyte ◽  
Excellent Reproducibility

AbstractA new nanocomposite electrolyte was synthesized using a simple non-hydrolytic sol-gel route without specific treatment of the reagents. The nanocomposite ion conductor was prepared with citric acid, tetraethyl orthosilicate and ethylene glycol, forming polyester chains. The time-consuming drying step that is a necessary part of most chemical syntheses was not required in the preparation of the present nanocomposite electrolyte of the polyelectrolyte class, because only Li+ is mobile in the polymeric chain. The effects of the concentration of Li, SiO 2 and SnO2nanoparticles were investigated in terms of Li+ ionic conductivity. Conductivity measurements as a function of the metal oxide nanocrystal content in the nanocomposite revealed a significant increase in conductivity at approximately 5 and 10 wt % of nanoparticles. The new nanocomposite conductor proved to be fully amorphous at room temperature, with a vitreous transition temperature of approximately 228K (−45°C). The material is solid and transparent, displaying an ionic conductivity of 10−4to 10−5 (O.cm)−1at room temperature presenting excellent reproducibility of all these characteristics. Cyclic voltammetry measurements indicate that the hybrid electrolyte possesses outstanding electrochemical stability.

Ionic Conductivity Measurements of LaF3 Polycrystalline Powders

2010 ◽  
Vol 663-665 ◽  
pp. 678-681
Author(s):  
Ming Zhou ◽  
Yan Wen Tian
Keyword(s):  
Ionic Conductivity ◽  
Impedance Spectroscopy ◽  
Sol Gel ◽  
Ionic Conductivities ◽  
Microwave Method ◽  
Conductivity Measurements ◽  
Industrial Grade ◽  
Gel Technique ◽  
Polycrystalline Powder

With the help of impedance spectroscopy, the complex impedances of three kinds of ultrafine LaF3 polycrystalline powders (industrial grade LaF3 polycrystalline powder, ultrafine LaF3 polycrystalline powder prepared with sol-gel technique, and ultrafine LaF3 polycrystalline powder prepared with microwave method) were measured, and their ionic conductivities were derived. It is found that the ionic conductivities of the industrial grade LaF3 polycrystalline powder and the ultrafine LaF3 polycrystalline powder prepared with microwave method are higher than that of the ultrafine LaF3 polycrystalline powder prepared with sol-gel technique.

Sign in / Sign up

Export Citation Format

Share Document