scholarly journals Effect of Chromium on Electrochemical and Mechanical Properties of Beta-Al2O3 Solid Electrolyte Synthesized Via a Citrate-Nitrate Combustion Method

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 987
Author(s):  
Jin Shi ◽  
Yongfei Hong ◽  
Chengfei Zhu
Keyword(s):  
Ionic Conductivity ◽  
Solid Electrolyte ◽  
Relative Density ◽  
Bending Strength ◽  
Electrochemical Impedance ◽  
Raw Materials ◽  
Combustion Method ◽  
Scanning Calorimetry ◽  
Al2o3 Phase ◽  
Precursor Powders

The beta-Al2O3 solid electrolyte doped with Chromium was synthesized via a citrate-nitrate combustion method, which started with NaNO3, LiNO3, Cr(NO3)3·9H2O, and Al(NO3)3·9H2O as the raw materials in this paper. The thermal behavior analysis, structure, and ionic conductivity of the beta-Al2O3 solid electrolyte were studied by the thermogravimetry/differential scanning calorimetry (TG/DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Meanwhile, the relative density and bending strength of the samples were also measured. The results showed that with the appropriate Chromium doping, the calcining temperature of the precursor powders was only 1100 °C, the β″-Al2O3 phase content, bending strength, relative density, and ionic conductivity were all improved with a compact and uniform cross section micrograph. The optimized sample contained 94% of β″-Al2O3 phase and exhibited a relative density up to 98.13% of the theoretical density. In addition, it showed a good bending strength (215 MPa) and a satisficed ionic conductivity (0.110 S cm−1 at 350 °C).

Synthesis of V2O5 Powders by EDTA Assistance Ultrasound Sol-Gel Process

2012 ◽  
Vol 512-515 ◽  
pp. 207-210
Author(s):  
Quan Wen ◽  
Jian Feng Huang ◽  
Li Yun Cao ◽  
Jian Peng Wu
Keyword(s):  
Activation Energy ◽  
Raw Materials ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Calcination Temperatures ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Precursor Powders ◽  
Influence Of Ph

V2O5 powders were successfully synthesized by the EDTA assistanced ultrasound sol-gel process using NH4VO3 and EDTA, NH3•H2O as raw materials. The synthesized activation energy and the influence of pH values and the calcination temperatures on the phases and microstructures of powders were particularly investigated. The precursor powders and the V2O5 powders were characterized by X-ray diffraction (XRD), fourier transform inelectron microscopy (FT-IR), scanning electron microscopy (SEM) and differential scanning calorimetry-thermal gravimetric (DSC-TG). Results show that the obtained products exhibit good crystallization under the conditions of pH=4, calcination temperature 400~500 °C and calcination time 0.5 h during the synthesizing process. The as-prepared V2O5 powders show preferred growth orientation along (001) plane at the pH=4. By DSC analysis, the ultrasonic cavitation result in the decrease in synthesized activation energy obviously than that was prepared without ultrasonic irradiation.

Extremely dense microstructure and enhanced ionic conductivity in hot-isostatic pressing treated cubic garnet-type solid electrolyte of Ga2O3-doped Li7La3Zr2O12

2018 ◽  
Vol 11 (02) ◽  
pp. 1850029 ◽  
Author(s):  
Shiying Qin ◽  
Xiaohong Zhu ◽  
Yue Jiang ◽  
Ming’en Ling ◽  
Zhiwei Hu ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Solid Electrolyte ◽  
Relative Density ◽  
Solid Electrolytes ◽  
Hot Isostatic Pressing ◽  
Lithium Ion ◽  
Nominal Composition ◽  
Isostatic Pressing ◽  
Dense Microstructure ◽  
Ion Conducting

A large number of pores and a low relative density that are frequently observed in solid electrolytes reduce severely their ionic conductivity and thus limit their applicability. Here, we report on the use of hot isostatic pressing (HIP) for ameliorating the garnet-type lithium-ion conducting solid electrolyte of Ga2O3-doped Li7La3Zr2O[Formula: see text] (Ga-LLZO) with nominal composition of Li[Formula: see text]Ga[Formula: see text]La3Zr2O[Formula: see text]. The Ga-LLZO pellets were conventionally sintered at 1075[Formula: see text]C for 12[Formula: see text]h, and then were followed by HIP treatment at 120[Formula: see text]MPa and 1160[Formula: see text]C under an Ar atmosphere. It is found that the HIP-treated Ga-LLZO shows an extremely dense microstructure and a significantly enhanced ionic conductivity. Coherent with the increase in relative density from 90.5% (untreated) to 97.5% (HIP-treated), the ionic conductivity of the HIP-treated Ga-LLZO reaches as high as [Formula: see text][Formula: see text]S/cm at room temperature (25[Formula: see text]C), being two times higher than that of [Formula: see text][Formula: see text]S/cm for the untreated one.

scholarly journals Optimization of the Electrochemical Performance of a Composite Polymer Electrolyte Based on PVA-K2CO3-SiO2 Composite

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 92
Author(s):  
Bashir Abubakar Abdulkadir ◽  
John Ojur Dennis ◽  
Yas Al-Hadeethi ◽  
Muhammad Fadhlullah Bin Abd. Shukur ◽  
E. M. Mkawi ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Polymer Electrolyte ◽  
Ionic Conduction ◽  
Electrochemical Impedance ◽  
Physicochemical Characterization ◽  
Composite Polymer Electrolyte ◽  
Composite Polymer ◽  
Energy Storage Devices ◽  
Scanning Calorimetry ◽  
Thermal Stabilities

Composite polymer electrolyte (CPE) based on polyvinyl alcohol (PVA) polymer, potassium carbonate (K2CO3) salt, and silica (SiO2) filler was investigated and optimized in this study for improved ionic conductivity and potential window for use in electrochemical devices. Various quantities of SiO2 in wt.% were incorporated into PVA-K2CO3 complex to prepare the CPEs. To study the effect of SiO2 on PVA-K2CO3 composites, the developed electrolytes were characterized for their chemical structure (FTIR), morphology (FESEM), thermal stabilities (TGA), glass transition temperature (differential scanning calorimetry (DSC)), ionic conductivity using electrochemical impedance spectroscopy (EIS), and potential window using linear sweep voltammetry (LSV). Physicochemical characterization results based on thermal and structural analysis indicated that the addition of SiO2 enhanced the amorphous region of the PVA-K2CO3 composites which enhanced the dissociation of the K2CO3 salt into K+ and CO32− and thus resulting in an increase of the ionic conduction of the electrolyte. An optimum ionic conductivity of 3.25 × 10−4 and 7.86 × 10−3 mScm−1 at ambient temperature and at 373.15 K, respectively, at a potential window of 3.35 V was observed at a composition of 15 wt.% SiO2. From FESEM micrographs, the white granules and aggregate seen on the surface of the samples confirm that SiO2 particles have been successfully dispersed into the PVA-K2CO3 matrix. The observed ionic conductivity increased linearly with increase in temperature confirming the electrolyte as temperature-dependent. Based on the observed performance, it can be concluded that the CPEs based on PVA-K2CO3-SiO2 composites could serve as promising candidate for portable and flexible next generation energy storage devices.

scholarly journals Submicron-Sized Nb-Doped Lithium Garnet for High Ionic Conductivity Solid Electrolyte and Performance of Quasi-Solid-State Lithium Battery

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 560 ◽  
Author(s):  
Yan Ji ◽  
Cankai Zhou ◽  
Feng Lin ◽  
Bingjing Li ◽  
Feifan Yang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Particle Size ◽  
Solid State ◽  
Ionic Conductivity ◽  
Relative Density ◽  
Electrochemical Impedance ◽  
Cubic Phase ◽  
Electrochemical Window ◽  
Long Time ◽  
Total Ionic Conductivity

The garnet Li7La3Zr2O12 (LLZO) has been widely investigated because of its high conductivity, wide electrochemical window, and chemical stability with regards to lithium metal. However, the usual preparation process of LLZO requires high-temperature sintering for a long time and a lot of mother powder to compensate for lithium evaporation. In this study submicron Li6.6La3Zr1.6Nb0.4O12 (LLZNO) powder―which has a stable cubic phase and high sintering activity―was prepared using the conventional solid-state reaction and the attrition milling process, and Li stoichiometric LLZNO ceramics were obtained by sintering this powder―which is difficult to control under high sintering temperatures and when sintered for a long time―at a relatively low temperature or for a short amount of time. The particle-size distribution, phase structure, microstructure, distribution of elements, total ionic conductivity, relative density, and activation energy of the submicron LLZNO powder and the LLZNO ceramics were tested and analyzed using laser diffraction particle-size analyzer (LD), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Electrochemical Impedance Spectroscopy (EIS), and the Archimedean method. The total ionic conductivity of samples sintered at 1200 °C for 30 min was 5.09 × 10−4 S·cm−1, the activation energy was 0.311 eV, and the relative density was 87.3%. When the samples were sintered at 1150 °C for 60 min the total ionic conductivity was 3.49 × 10−4 S·cm−1, the activation energy was 0.316 eV, and the relative density was 90.4%. At the same time, quasi-solid-state batteries were assembled with LiMn2O4 as the positive electrode and submicron LLZNO powder as the solid-state electrolyte. After 50 cycles, the discharge specific capacity was 105.5 mAh/g and the columbic efficiency was above 95%.

Production of Ceramic Materials Using only Waste as Raw Materials

2015 ◽  
Vol 663 ◽  
pp. 62-71 ◽  
Author(s):  
R.J. Galán-Arboledas ◽  
Salvador Bueno
Keyword(s):  
Power Plant ◽  
Bending Strength ◽  
Raw Materials ◽  
Equilibrium Diagram ◽  
Thermo Gravimetric Analysis ◽  
Main Tool ◽  
Ceramic Materials ◽  
Absorption Capacity ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry

From a selection of inorganic industrial waste (screen glass, steelworks ashes, coal power plant ashes, biomass power plant ash and sludge from cutting marble industry) and a waste with organic fraction (diatomaceous earth from oil filtration) it is expected to obtain ceramic materials with properties similar to those of ceramic materials used in construction and porous materials with thermal insulating capability. The ternary phase equilibrium diagram SiO2-Al2O3-CaO has been used as the main tool for the formulation of these materials. The dynamic sintering study was carried out using dilatometry techniques (DIL), thermo gravimetric analysis and differential scanning calorimetry (TG-DSC). Characterization of the manufactured material allows determining a set of basic technological properties such as fired bulk density, water absorption capacity and bending strength, in addition to thermal conductivity and microstructure by SEM-EDX, in order to obtain the necessary data to determine technical feasibility.

Effect of Sintering Pressure on Mechanical Properties of BN-Si3N4 Ceramic Composites Prepared by Spark Plasma Sintering

2016 ◽  
Vol 697 ◽  
pp. 188-192
Author(s):  
Jia Xin An ◽  
Wen Dong Xue ◽  
Feng Rui Zhai ◽  
Ruo Meng Xu ◽  
Jia Lin Sun
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Raw Materials ◽  
Ceramic Composites ◽  
Composite Ceramics ◽  
Plasma Sintering ◽  
Spark Plasma

BN-Si3N4 composite ceramic wave-transparent materials with excellent mechanical properties were prepared by spark plasma sintering (SPS) using h-BN and α-Si3N4 powders as raw materials, Al2O3 and Y2O3 as sintering aids. The influence of sintering pressure on density and mechanical properties of BN-Si3N4 composite ceramics were studied. The phases were observed by X-ray diffraction (XRD), and the microstructures were identified by scanning electron microscopy (SEM). The results showed that with the sintering pressure increases, the relative density, bending strength and fracture toughness of the composite ceramics were significantly increased, and the porosity decreased rapidly. The effects of pressure on the properties of the composite ceramics was not significant at >40MPa, so 40MPa is optimal for the composite ceramics to gain good overall performance, i.e. the relative density was 89.1%, the porosity was 2.3%, the bending strength reached 215.4 MPa, and the fracture toughness was 3.1/MPa·m1/2.

Preparation of Y-Doped BaZrO3 Proton Conducting Solid Electrolyte via Modified Low Temperature Pechini Method

2015 ◽  
Vol 1098 ◽  
pp. 86-91 ◽  
Author(s):  
Gandy Nuñez ◽  
Mary Jozen Balanay ◽  
Rinlee Butch M. Cervera
Keyword(s):  
Solid Electrolyte ◽  
Raw Materials ◽  
Pechini Method ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Cubic Phase ◽  
Sintered Pellet ◽  
Powder Preparation ◽  
Proton Conducting ◽  
Intermediate Temperature Range

One of the promising material for proton-conducting solid electrolyte operating at intermediate temperature range (400-600 °C) is the Yttrium-doped BaZrO3 (BZY) due to its high conductivity and chemical stability. In this study, a modified citrate-nitrate combustion method (Pechini method) has been employed for BZY powder preparation. A stoichiometric amounts of starting nitrates and oxide raw materials with nitric acid, citric acid and ethylene glycol for the synthesis of 20 mol% Y-doped BaZrO3 (BZY20) were prepared, then calcined and sintered at 1000 °C for two heat treatment durations of 24 hours and 48 hours. The obtained BZY20 powder samples have been fully characterized for its structure, morphology, and thermal properties. From the X-ray diffraction (XRD) results, the sample sintered for 48 hours showed a cubic phase of BZY20 which can be indexed to a Pm3m cubic structure which is also supported by Raman analysis. The calculated lattice parameter is 4.2067 Å which is higher than the reported lattice parameter of a pure BaZrO3 (BZ) of 4.1930 Å which indicates a successful doping due to higher ionic radius of Y3+ dopant as compared to Zr4+ in the B-site ABO3 perovskite sub-lattice. In addition, SEM-EDX analyses of the sintered pellet revealed a uniform distribution of Yttrium dopant in the BZY20 prepared solid electrolyte.

scholarly journals A cost-effective and humidity-tolerant chloride solid electrolyte for lithium batteries

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kai Wang ◽  
Qingyong Ren ◽  
Zhenqi Gu ◽  
Chaomin Duan ◽  
Jinzhu Wang ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Solid Electrolyte ◽  
Solid Electrolytes ◽  
Large Scale ◽  
Room Temperature ◽  
Raw Materials ◽  
Specific Capacity ◽  
Cost Effective ◽  
High Ionic Conductivity ◽  
Superionic Conductors

AbstractLi-ion-conducting chloride solid electrolytes receive considerable attention due to their physicochemical characteristics such as high ionic conductivity, deformability and oxidative stability. However, the raw materials are expensive, and large-scale use of this class of inorganic superionic conductors seems unlikely. Here, a cost-effective chloride solid electrolyte, Li2ZrCl6, is reported. Its raw materials are several orders of magnitude cheaper than those for the state-of-the-art chloride solid electrolytes, but high ionic conductivity (0.81 mS cm–1 at room temperature), deformability, and compatibility with 4V-class cathodes are still simultaneously achieved in Li2ZrCl6. Moreover, Li2ZrCl6 demonstrates a humidity tolerance with no sign of moisture uptake or conductivity degradation after exposure to an atmosphere with 5% relative humidity. By combining Li2ZrCl6 with the Li-In anode and the single-crystal LiNi0.8Mn0.1Co0.1O2 cathode, we report a room-temperature all-solid-state cell with a stable specific capacity of about 150 mAh g–1 for 200 cycles at 200 mA g–1.

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

Low-Cost Raw Materials Synthesized Na 2.9375PS 3.9375Cl 0.0625 Solid Electrolyte

2019 ◽  
Author(s):  
Yu Wang ◽  
Nachuan Yang ◽  
Yi Shuai ◽  
Yunpeng Zhang ◽  
Kanghua Chen
Keyword(s):  
Solid Electrolyte ◽  
Raw Materials ◽  
Low Cost
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