scholarly journals Electrical Properties of Li-based NASICON Structured Ceramic Electrolytes Substituted With Chromium

2019 ◽  
Vol 7 (4.14) ◽  
pp. 555
Author(s):  
N. A. Mustaffa ◽  
N. S. Mohamed ◽  
. .
Keyword(s):  
Electrical Properties ◽  
Grain Boundary ◽  
Room Temperature ◽  
Electronic Conductivity ◽  
Ionic Mobility ◽  
Electrical Impedance Spectroscopy ◽  
Ion Concentration ◽  
Boundary Conductivity ◽  
Ceramic Electrolytes ◽  
Ion Conducting

Electrical properties of Li - ion conducting Li1+xCrxSn2-x(PO4)3 ceramic electrolytes with 0 < x < 1 were studied using electrical impedance spectroscopy in the frequency range of 1 Hz to 10 MHz at room temperature. Impedance analysis showed an increase in bulk and grain boundary conductivity with the increment of x up to x = 0.7. The highest bulk and grain boundary conductivity were 6.52 ×10-6 S cm-1 and 1.62 ×10-6 S cm-1 in the system of Li1.7Cr0.7Sn1.3(PO4)3 at room temperature. The charge carrier concentration,   mobile ion concentration, ionic hopping rate and ionic mobility were calculated by fitting the AC conductivity spectra. The ionic hopping rate and ionic mobility of the compound increased with the substitution of chromium due to the extra interstitial Li+ ions in the system.  Additionally, the highest conducting sample with x = 0.7 had a negligible electronic conductivity based on transference number measurements. These results imply that the Li1+xCrxSn2-x(PO4)3 electrolytes obtained in this work can be considered as future candidates for solid state electrolytes.  

Effect of BaCO3 and Pb3O4 on Properties of BaTiO3-Based PTCR Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 349-352
Author(s):  
Wei Bing Ma ◽  
Yuan Fang Qu ◽  
Yan Xia Hao
Keyword(s):  
Electrical Properties ◽  
Grain Boundary ◽  
High Performance ◽  
Room Temperature ◽  
Sintering Behavior ◽  
Low Resistivity ◽  
Phase Constituent ◽  
Weak Reduction ◽  
Grain Boundary Resistivity

High-performance PTCR ceramics with low resistivity (8Ω.cm) at room temperature and around four orders magnitude of the PTCR jump were obtained by adding BaCO3 and Pb3O4(B-P) in BaTiO3. The influence of adding B-P on the sintering behavior, the microstructure and the electrical properties of BaTiO3-based PTCR was investigated. The phase constituent in the sintered ceramics was analyzed by XRD and it was shown that the metallic layered Ba3Pb2O7 phase was synthesized during the sintering. Analysis suggested that making the weak reduction atmosphere at the grain boundary may decrease the grain-boundary resistivity.

scholarly journals Effect of Annealing Temperature on the Li\(^{ + }\) Ionic Conductivity of La\(_{0.67 - x}\)Li\(_{3x}\)TiO\(_{3 }\)

2009 ◽  
Vol 19 (4) ◽  
pp. 235-242
Author(s):  
Le Dinh Trong ◽  
Pham Duy Long ◽  
Nguyen Nang Dinh
Keyword(s):  
High Temperature ◽  
Ionic Conductivity ◽  
Thermal Treatment ◽  
Grain Boundary ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Boundary Conductivity ◽  
Impedance Measurements ◽  
Post Annealing ◽  
Reactive Milling

Perovskite La0.67-xLi3xTiO3 with x = 0.10, 0.11, 0.12 and 0.13 were firstly annealed at 800 oC then treated by reactive milling, followed by post-annealing at temperatures from 1100 to 1200oC. The crystalline structure of grain and grain-boundary were characterized by XRD and SEM. The impedance measurements showed that nanocrystalline La0.67-xLi3xTiO3 after being annealed at 1150 oC possessed a grain conductivity as high as 1.3×10-3 S.cm-1. The grain-boundary conductivity was enhanced one order in magnitude after annealing at temperature higher 1100oC and consists of 5.8×10-5 S.cm-1. The results have also showed the limitation of the adiabatic thermal treatment for the improvement of the grain-boundary conductivity and suggested the way to overcome the limitation by rapidly cooling the samples from the high temperature to room temperature.

scholarly journals An electrochemically stable defect-free glassy electrolyte formed at room temperature for all-solid-state sodium batteries

2021 ◽  
Author(s):  
Xiaowei Chi ◽  
Ye Zhang ◽  
Fang Hao ◽  
Steven Kmiec ◽  
Hui Dong ◽  
...  
Keyword(s):  
Solid State ◽  
Network Structure ◽  
Room Temperature ◽  
Glass Structure ◽  
Electronic Conductivity ◽  
Microstructural Analysis ◽  
Glass Network ◽  
Electrochemical Stability ◽  
Sodium Batteries ◽  
Ion Conducting

Abstract All-solid-state sodium batteries (ASSSBs) are promising candidates for grid-scale energy storage applications. To date, however, there are no commercialized ASSSBs due in part to the lack of a solid electrolyte (SE) that meets all of the requirements of low cost, facile fabrication, high Na+ conductivity, electrochemical stability, and is resistant to sodium metal dendrite penetration. In this work, we report a family of oxysulfide glass SEs (Na3PS4−xOx, where 0 < x ≤ 0.6) that combine the advantages of sulfides and oxides, we demonstrate stable electrochemical cycling of Na metal for hundreds of hours and the highest critical current density of 2.3 mA cm−2 among all Na-ion conducting sulfide-based SEs. These performance enhancements are found to be associated with the ability of the oxysulfide glass to undergo room temperature pressure induced amorphization that creates a fully homogeneous glass structure that has robust mechanics and substantial chemical and electrochemical stability. Microstructural analysis revealed that the added oxygen creates a glassy network structure by forming bridging oxygen units resulting in a significantly stronger defect-free glass network and two orders of magnitude lower electronic conductivity compared to the fully ionic and non-network structure of Na3PS4. We show ambient-temperature sodium-sulfur batteries (ATSSBs) can be fabricated from these SEs that demonstrate the highest specific energy among the current sodium batteries. The unique room-temperature processing of composite SE structures may provide a sustainable path forward for the further development of ATSSBs in particular and ASSSBs in general.

Microstructural Correlation with Electrical Properties for Y2O3 Doped CeO2 Thin Films

1997 ◽  
Vol 500 ◽  
Author(s):  
Chunyan Tian ◽  
Siu-Wai Chan
Keyword(s):  
Electrical Properties ◽  
Grain Boundary ◽  
Complex Impedance ◽  
Fused Silica ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Boundary Conductivity ◽  
Bulk Ceramic ◽  
Transmission Electron ◽  
Beam Deposition

ABSTRACTHigh quality textured 0.58% Y2O3 doped CeO2 films with (001), (111)/(001) and (110) were prepared using an e-beam deposition technique on substrates of (001) LaAlO3, r-cut sapphire, and fused silica, respectively. The composition and stoichiometry of the films were verified by Rutherford backscattering spectroscopy analysis. Both x-ray diffraction and transmission electron microscopy analyses gave consistent microstructural information. Complex impedance measurements have been performed to study the electrical properties of these films as a function of temperature. The conductivities of the films were dominated by grain boundaries of high conductivities as compared to that of the bulk ceramic of the same dopant concentration. The activation energies for the film conductivities were only slightly higher than that for the bulk lattice conductivities, but much lower than that for the bulk grain boundary conductivity. These results have been discussed in terms of the differences of the grain size and grain boundary microstructures between the films and the bulk ceramics.

scholarly journals Influence of Lithium Content on the Structure and Ionic Conductivity of Perovskite \(\mbox{La}_{(2/3) - x}\mbox{Li}_{3x}\mbox{TiO}_{3}\) Made by Double Mechanical Alloying Method

2014 ◽  
Vol 24 (3S1) ◽  
pp. 33-39
Author(s):  
Le Dinh Trong
Keyword(s):  
Activation Energy ◽  
Ionic Conductivity ◽  
Grain Boundary ◽  
Mechanical Alloying ◽  
Room Temperature ◽  
Lithium Content ◽  
Boundary Conductivity ◽  
Structural Modifications ◽  
Li Ion ◽  
Conductive Properties

Perovskite La\(_{(2/3) - x}\)Li\(_{3x}\)TiO\(_{3}\) samples with 0.06 \( \leq x \leq 0.15\) were prepared by a double mechanical alloying method. Structure and Li$^{ + }$-ion conductive properties of the La\(_{(2 / 3) - x}\)Li\(_{3x}\)TiO\(_{3}\) samples were investigated. Most of the analyzed perovskite samples exhibit a double unit cell. In these samples, a change of symmetry from tetragonal to orthorhombic is observed for sample with lithium content x = 0.06. Structural modifications were obtained mainly due to the cation vacancies ordering along the c-axis, which disappeared gradually when the lithium content increased. At room temperature, the maximum values of grains and grain boundaries conductivities of the La\(_{(2 / 3) - x}\)Li\(_{3x}\)TiO\(_{3}\) samples were found to be of \(1.5\times 10$^{ - 3}\) S/cm and \(5.8 \times 10^{ - 5}\) S/cm, respectively. The temperature dependence of ionic conductivity obeyed a non-Arrhenius behaviour. At temperature from 30 to 125\(^{\circ}\)C, the activation energy for grain and grain-boundary conductivity was found to be of $\sim $ 0.23 eV and $\sim $ 0.32 eV, respectively.

scholarly journals Magnetic and electrical properties of Cr substituted Ni nano ferrites

2018 ◽  
Vol 12 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Kumar Vijaya ◽  
Rapolu Sridhar ◽  
Dachepalli Ravinder
Keyword(s):  
Electrical Properties ◽  
Room Temperature ◽  
Average Crystallite Size ◽  
Soft Magnetic Materials ◽  
Ion Concentration ◽  
Dc Resistivity ◽  
Soft Magnetic ◽  
Loop Area ◽  
Auto Combustion ◽  
Resistivity Variation

Nano-ferrites with composition NiCrxFe2-xO4 (where x = 0.1, 0.3, 0.5, 0.7, 0.9, 1.0) were synthesized through citrate-gel auto combustion technique at moderately low temperature. X-ray analysis shows cubic spinel structure single phase without any impurity peak and average crystallite size in the range 8.5-10.5 nm. Magnetic properties were measured using a vibrating sample magnetometer at room temperature in the applied field of ?6 KOe. The obtained M-H loop area is very narrow, hence the synthesized nano ferrites are soft magnetic materials with small coercivity. Magnetic parameters such as saturation magnetization (Ms), coercivity (Hc), remanent magnetization (Mr) and residual magnetization were measured and discussed with regard to Cr3+ ion concentration. Electrical properties were measured using two probe method from room temperature to well beyond transition temperature. The DC resistivity variation with temperature shows the semiconductor nature. Resistivity, drift mobility and activation energy values are measured and discussed with regard to composition. The Curie temperature was determined using DC resistivity data and Loria-Sinha method. The observed results can be explained in detail on the basis of composition.

Improving Gd-Doped Ceria Electrolytes for Low Temperature Solid Oxide Fuel Cells

1999 ◽  
Vol 575 ◽  
Author(s):  
J. M. Ralph ◽  
J. A. Kilner ◽  
B. C. H. Steele
Keyword(s):  
Fuel Cells ◽  
Grain Boundary ◽  
Solid Oxide Fuel Cells ◽  
Electronic Conductivity ◽  
Solid Oxide ◽  
Doped Ceria ◽  
Oxide Fuel ◽  
Boundary Conductivity ◽  
Second Phases ◽  
Impurity Elements

ABSTRACTGadolinia-doped ceria electrolyte is being investigated as an alternative electrolyte for solid oxide fuel cells operating at temperatures below 700°C. Measurements were made to determine the effects that small additions of Ca, Pr and Fe to gadolinia-doped ceria have on the bulk and grain boundary conductivities. These small additions (1–2%) of dopant did not alter the bulk conductivity significantly but resulted in a large increase in the grain boundary conductivity. The grain boundary conductivity was similar for all three electrolyte compositions. These results are explained by the possible formation of second phases at the grain boundary, which can incorporate impurity elements. The electronic conductivity in these electrolyte materials was also evaluated, but it was found that the Ca, Pr and Fe additions do not reduce the electronic conductivity compared to a standard Gd-doped ceria sample.

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