Preparation, Thermal Stability and Electrochemical Properties of LiODFB

2012 ◽  
Vol 152-154 ◽  
pp. 1106-1111 ◽  
Author(s):  
Hong Ming Zhou ◽  
Fu Rong Liu ◽  
Jian Li
Keyword(s):  
Thermal Stability ◽  
Electrochemical Properties ◽  
Dimethyl Carbonate ◽  
Ethylene Carbonate ◽  
Specific Capacity ◽  
Decomposition Temperature ◽  
Structure Characterization ◽  
Good Thermal Stability ◽  
Ethyl Methyl ◽  
Xrd Patterns

Lithium difuoro(axalato)bonate (LiODFB) was synthesized in dimethyl carbonate solvent and purified by the method of solventing-out crystallization. The structure characterization and thermal stability of LiODFB was performed by Fourier transform infrared (FTIR) spectrometry, nuclear magnetic resonance (NMR) spectrometry and thermogravimetric analyzer (TGA). LiODFB was exposed to 50% humidity air at 25°C for different time, then dried at 80°C for 12h, and the electrochemical properties of the cells using 1 mol/L dried LiODFB in ethylene carbonate + dimethyl carbonate + ethyl(methyl)carbonate were investigated. The results show that, pure crystallization LiODFB has been obtained; it has good thermal stability with a thermal decomposition temperature of 248°C; exposed to humidity air, it is firstly converted into LiODFB•H2O; with the exposed time increasesing, more and stronger impurity peaks in the XRD patterns of LiODFB are observed, both the discharge specific capacity and the capacity retention decrease gradually

Synthesis and Electrochemical Properties of 0.5Li2MnO3•0.5LiMn0.5Ni0.5O2

2010 ◽  
Vol 105-106 ◽  
pp. 664-667
Author(s):  
Sheng Wen Zhong ◽  
Wei Hu ◽  
Qian Zhang
Keyword(s):  
Cathode Material ◽  
Electrochemical Properties ◽  
Specific Capacity ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Discharge Specific Capacity ◽  
Xrd Patterns ◽  
Co Precipitation ◽  
Two Stages ◽  
Calcined Temperature

The precursor of Mn0.75Ni0.25CO3 is prepared by carbonate co-precipitation method. And the cathode material 0.5Li2MnO3•0.5LiMn0.5Ni0.5O2 is synthesized with two stages calcining temperatures T1 and T2. T1 represents 400°C, 500°C, 600°C and T2 is selected at 750°C, 850°C, 950°C respectively. XRD Patterns shows that the cathode material has the integrated structures of Li2MnO3 and LiMO2, and it has better crystallization during the rise of calcined temperature at 950°C. The electrochemical performances tests indicates that the initial discharge specific capacity are greater than 220mAh/g at the current density 0.2 mA/cm2 in 2.5-4.6V at room temperature. When cathode material is calcined at 750°C, its discharge specific capacity even reach to 248mAh/g, but the cathode material has more perfect general electrochemical properties during calcined temperature at 950°C.

scholarly journals Stable Organic-Inorganic Hybrid Bismuth-Halide Monocrystalline Compounds With Adjustable Optoelectronic Properties

2021 ◽  
Author(s):  
Xinru Hu ◽  
Jilin Wang ◽  
Jian He ◽  
Guoyuan Zheng ◽  
Disheng Yao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Room Temperature ◽  
Diffuse Reflectance ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Good Thermal Stability ◽  
Chemical Groups ◽  
Thermal Stability Of

Abstract Two kinds of novel organic-inorganic bismuth-halide hybrid monocrystalline compounds (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 were synthesized and characterized. The crystal structure, intermolecular interaction, morphology, chemical groups and bonds, optical and thermal stability of the samples were systematically investigated through single crystal X-ray diffraction, Hirshfeld surface analysis, SEM, FTIR, TG and UV-vis diffuse reflectance spectra. The results indicated that (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 crystals displayed a monoclinic system with the space group P21/c and P21/n at room temperature, respectively. These materials showed strong absorption in the ultraviolet and visible light regions, resulting in very low Eg, which could be continuously adjustable from 1.67 eV to 3.21 eV by changing the halogen ratio. In addition, these hybrid materials also exhibited good thermal stability. The decomposition temperature of (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 were 260℃ and 300℃ respectively. Therefore, these organic-inorganic bismuth-halide hybrid compounds have excellent development potential in the field of solar cell research.

Synthesis of a metal-coordinated N-substituted polybenzimidazole pyridine sulfone and method for the nondestructive analysis of thermal stability

2018 ◽  
Vol 31 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Peng Yang ◽  
Li Yang ◽  
Junxiao Yang ◽  
Xuan Luo ◽  
Guanjun Chang
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
High Performance ◽  
Decomposition Temperature ◽  
Metal Coordination ◽  
Thermal Decomposition Temperature ◽  
Quenching Effect ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Performance Functional

N-substituted metal-coordinated cross-linking polybenzimidazole pyridine sulfone, as novel class of high-performance functional polymers, has been obtained by the coordination of N-substituted polybenzimidazole pyridine sulfone (Py-N-PBIS) ligand with varying content of metallic ion (Co2+, Ni2+, Zn2+). The structures of the polymers are characterized by means of fourier transform infrared spectroscopy (FT-IR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy, the results show good agreement with the proposed structures. Thermogravimetric analysis measurements exhibit that the metal coordination polymers possess good thermal stability with high thermal decomposition temperature (thermally stable up to 405–510°C). More importantly, the thermal decomposition temperature of Py-N-PBIS-(Co2+, Ni2+, Zn2+) can be nondestructively detected by taking advantage of the fluorescence quenching effect of metal coordination to 2,6-Bis(2-benzimidazolyl)pyridine structure.

scholarly journals Hardly Flammable Polyurethane Foams with 1,3-Pyrimidine Ring and Boron Atoms

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1603
Author(s):  
Elżbieta Chmiel-Szukiewicz
Keyword(s):  
Thermal Stability ◽  
Water Absorption ◽  
Ethylene Carbonate ◽  
Pyrimidine Ring ◽  
Polyurethane Foams ◽  
Good Thermal Stability ◽  
Negative Effect ◽  
Instrumental Methods ◽  
Foam Production

This work presents the results of research related to the determination of application possibilities of new oligoetherols with 1,3-pyrimidine rings and boron atoms in rigid polyurethane foam production. Oligoetherols were obtained from 1,3-bis(2-hydroxyethyl)uracil, boric acid, and ethylene carbonate. Their structure was determined by instrumental methods (IR, 1H-NMR and MALDI-ToF spectra) and the physicochemical and thermal properties were examined. Obtained oligoetherols were used for synthesis of polyurethane foams. Some properties of the foams, such as apparent density, water uptake, dimensions stability, thermal stability, compression strength, thermal conductivity, oxygen index, and horizontal burning were investigated. The introduction of boron atoms into the foam structure reduced their flammability, but unfortunately it had a negative effect on the water absorption of the obtained materials—the water absorption was higher compared to the boron-free foams. The obtained foams showed good thermal stability compared to classic, rigid polyurethane foams.

Polyhydroxyalkylation of urea with ethylene carbonate and application of obtained products as components of polyurethane foams

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Iwona Zarzyka-Niemiec
Keyword(s):  
Thermal Stability ◽  
Compressive Strength ◽  
Ethylene Carbonate ◽  
Polyurethane Foams ◽  
Urea Derivatives ◽  
Good Thermal Stability ◽  
Low Mass ◽  
Products Of Reaction ◽  
Derivatives Of ◽  
Partial Release

AbstractThe reaction between urea and ethylene carbonate occur with partial release of CO2 and partial incorporation of carbonate groups into products. The carbonate groups were found to be attached both to nitrogen of urea and to oxyethylene chain. The most effective catalyst of the synthesis was potassium carbonate. The hydroxyethyl and hydroxyethoxy groups of urea derivatives undergo partial dimerization to form carbamate groups in the products. The products of reaction between urea and ethylene carbonate have good thermal stability, they start to decompose at 200°C. The obtained products can be used as polyol components for polyurethane foams. Polyurethane foams obtained from hydroxyethoxy derivatives of urea (EC8) are rigid products of low water uptake, good stability of dimensions, low mass loss on 30 days heating at 150°C, enhanced thermal stability and good compressive strength.

Synthesis and Optical Properties of Dipolar Thiazole Derivatives Incorporating Nitro and Amino Substituents

2018 ◽  
Vol 773 ◽  
pp. 157-161
Author(s):  
Ahmad Shah Noor Aisyah ◽  
Nur Farahin Pairan ◽  
Noor Azilah Mohd Kasim ◽  
Bohari Mohd Yamin
Keyword(s):  
Thermal Stability ◽  
Optical Properties ◽  
Electron Acceptor ◽  
Decomposition Temperature ◽  
Amino Group ◽  
Thiazole Derivatives ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Ft Ir ◽  
C Nmr

We report the synthesis of two dipolar thiazole derivatives functionalized with nitro group as electron acceptor and amino group as electron donor, in order to study their optical properties in the UV-vis range. Their structures were verified by 1H NMR, 13C NMR, HRMS and FT-IR. The resulted thiazole derivatives have good thermal stability with decomposition temperature, Td of 320.20 °C and 284 °C for compounds 1 and 2 respectively. The absorbance bands of compound 2 in the UV-vis range are more red-shifted than that of compound 1 which made compound 2 could have high potential as a great organic NLO material.

scholarly journals Thermal stability of n-TiB2 reinforced α-Al2O3/SiC based nanocomposite sintered at 1600˚C using TG/DTA under controlled Ar atmosphere

2021 ◽  
Vol 9 (4B) ◽  
Author(s):  
Tamilselvam Nallusamy ◽  
◽  
Vijayakumar S ◽  
Keyword(s):  
Thermal Stability ◽  
Gas Turbine ◽  
Rocket Engine ◽  
Cutting Tools ◽  
Titanium Boride ◽  
Decomposition Temperature ◽  
Turbine Engine ◽  
Good Thermal Stability ◽  
Α Al2o3 ◽  
Thermal Stability Of

Innovation in material science progresses the usage of Al2O3/SiC based nanocomposites in gas turbine engine components, the harp-shaped structure of hypersonic rocket engine cutting tools for Ni, Al alloys, and clutch plate for two-wheelers. Thermal stability is one of the significant properties of gas turbine and rocket engine materials. Future engines may have to operate at very high temperature that may require high thermally stable material. In this research, an attempt is made to enhance the thermal stability of the Al2O3/SiC based nanocomposite by reinforcing 5-20 Vol. % nano Titanium Boride. Fabrication of α-Al2O3/SiC with 5-20 Vol. % n-TiB2 was carried out through pressureless sintering at 1600˚C followed by cold compaction. The fabrication process was carried out at a controlled Ar atmosphere. Thermal stability of the sintered samples was analyzed by NETZSCH STA 449F3 thermogravimetric analyzer with a heating rate of 10˚C/min and compared with Al2O3/SiC. The composite α-Al2O3/SiC/(5-20 Vol. %) n-TiB2 showed good thermal stability up to 1488˚C with 6% less mass change than Al2O3/SiC. The addition of n-TiB2 enhanced the collaboration between the atoms and postponed the decomposition temperature. The microstructure of the 20 vol % n-TiB2 added α-Al2O3/SiC was captured by 20 kV JSM-5600J Scanning Electron Microscopy and confirmed the presence of n-TiB2. Also, the presence of Ti, Si, Al, O, and B in the nanocomposite was confirmed by energy dispersive analysis of X-beams (EDS).

scholarly journals Reactions of N,N′-bis(2-hydroxyethyl)oxalamide with Ethylene Carbonate and Use of the Obtained Products as Components of Polyurethanes Foams

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Iwona Zarzyka-Niemiec
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Physical Properties ◽  
Ethylene Carbonate ◽  
Polyurethane Foams ◽  
Reaction Conditions ◽  
Good Thermal Stability ◽  
Molar Excess ◽  
Instrumental Methods ◽  
Derivatives Of

-bis(2-hydroxyethyl)oxalamide (BHEOA) was subject to hydroxyalkylation with ethylene carbonate (EC). By means of instrumental methods (IR, -NMR, MALDI ToF, GC, and GC-MS), an influence of the reaction conditions on structure and compositions of the obtained products was investigated. The hydroxyalkyl and hydroxyalkoxy derivatives of oxalamide (OA) were obtained by reaction of BHEOA with 2–10-molar excess of ethylene carbonate (EC, 1,3-dioxolane-2-one). The products have a good thermal stability and possess suitable physical properties as substrates for foamed polyurethanes. The obtained products were used in manufacturing the rigid polyurethane foams which possess enhanced thermal stability and good mechanical properties.

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