Effects of Y3+-Doping on the Electrochemical Properties of LiV3O8 Cathode Material Prepared by a Solid-State Method

2011 ◽  
Vol 391-392 ◽  
pp. 1363-1367
Author(s):  
Yong Mei Liu ◽  
Hui Juan Li ◽  
Jie Ni

A series of yttrium-doped lithium trivanadates LiV3-yYyO8 (y=0, 0.01, 0.03, 0.05, 0.1 and 0.2) were synthesized by a solid-state reaction. X-ray diffraction (XRD) tests show that a proper amount of yttrium doping in LiV3O8 can modify its structure. Charge-discharge tests show that doped samples with a proper amount of yttrium display good cycling stability compared with undoped sample. The cyclic voltammetry (CV) tests indicate that the proper amount of yttrium doping in LiV3O8 can stabilize its original structure. Yttrium doping is a convenient and effective method for improving the electrochemical performances of LiV3O8.

2012 ◽  
Vol 554-556 ◽  
pp. 436-439 ◽  
Author(s):  
An Ping Tang ◽  
Ze Qiang He ◽  
Jie Shen ◽  
Guo Rong Xu

Lithium vanadyl phosphate (β-LiVOPO4) cathode material for lithium ion batteries was prepared via a novel solid state method. The microstructure and electrochemical properties of the sample were characterized by X-ray diffraction, scanning electron microscopy, galvanostatically discharge/discharge and cyclic voltammetry techniques, respectively. X-ray diffraction patterns showed that β-LiVOPO4 has an orthorhombic structure with space group of Pnma. The discharge capacity of LiVOPO4 sample is 89.9 mAh•g-1 in the first cycle, and in the 50th cycle it is 76.2 mAh•g-1 at the current density of 10 mA•g-1 between 3.0-4.5 V. The chemical diffusion coefficient ( ) value determined from CV is about 10-11 cm2 s-1. Experimental results indicate that further efforts are needed to improve electrochemical performances of LiVOPO4 material synthesized by solid state method; however, it has a higher discharge plateau around 3.9 V.


2016 ◽  
Vol 703 ◽  
pp. 316-320
Author(s):  
Hai Feng Chen ◽  
Jing Ling Hu ◽  
Bing Xu

Using NH4VO3, Bi (NO3)3•5H2O and Co (NO3)2•6H2O as raw materials, Co doped BiVO4 (Co/BiVO4) photocatalysts were successfully prepared by solid state method. And the photo catalytic properties were test in this work. Crystal structures of these samples were characterized by X-ray diffraction (XRD). The Methyl Orange (MO) was simulated as the sewage under the visible light to explorer the influence of the illumination time and the mass of photocatalyst. The visible-light absorption spectrum of BiVO4 was broadening with doping Co. It was found that the Co/BiVO4 had higher photocatalytic activity than pure BiVO4 .The reason of enhanced catalytic effect also had been analyzed and discussed in the article.


2011 ◽  
Vol 412 ◽  
pp. 61-64
Author(s):  
Xiao Bo Wu ◽  
Da Zhi Sun ◽  
Dan Yu Jiang ◽  
Hai Fang Xu ◽  
De Xin Huang ◽  
...  

3Y-TZP powder has been successfully synthesized by gel solid-state method. The structural phases of powder particles were analyzed by X-ray diffraction and the morphology was analyzed by scanning electron microscopy. The average size of grains was 230 nm. The sintering behavior, mechanical properties and microstructure of 3Y-TZP ceramics sintered by this powder were investigated. The experiment results showed that the mechanical properties of ceramics were excellent.


2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Hamadi Hamza ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss

LiNa5K3Mo11As3O45 is a new inorganic compound. It was synthesized by a solid state method. The crystal structure has been studied by single crystal X-ray analysis. The R-values reached 2.8%. The title compound crystallizes in the triclinic system, space group P-1, with a = 10.550 (2) Å, b = 11.723 (2) Å, c = 17.469 (3) Å, α = 102.35 (3)°, β = 87.61 (2)°, and γ = 111.03 (3)°. The anionic unit [Mo11As3O45]9− is formed by nine MoO6 octahedra, two MoO5 trigonal bipyramids, and three AsO4 tetrahedra. The association of [Mo11As3O45]9− units, running along [010], leads to a one-dimensional framework. Li, K, and Na are located in the space surrounding the anionic ribbons. This material was characterized by SEM microscopy, IR spectroscopy, and powder X-ray diffraction. The electrical conductivity was investigated from 528 K to 673 K by impedance complex followed by DSC spectroscopy.


2012 ◽  
Vol 602-604 ◽  
pp. 1044-1049 ◽  
Author(s):  
You Rong Wang ◽  
Han Tao Liao ◽  
Jia Wang ◽  
Yu Chan Zhu ◽  
Si Qing Cheng

In order to enhance the electrochemical performance of LiMnPO4 cathode material, we optimized the synthesis conditions of LiMnPO4 using a simple solid state reaction. The influence of factors of the pre-sintering temperature, carbon source and molar ratio of Zn to Mn, as well as the electrochemical properties of obtained LiMnPO4 powder were studied. The precursor of Zn-doping LiMnPO4/C was characterized by Differential Scanning Calorimetry and thermogravimetry. The microstructure of the samples was characterized by X-ray diffraction (XRD). The optimized LiMnPO4 cathode has good electrochemical properties and its discharge capacity could reach 140.2 mAh g−1 at 0.02 C rate and 111.3 mAh g−1 at 0.1 C rate with satisfactory cycling performance. It implies that the synthesis of LiMnPO4/C composite with excellent electrochemical performances can be achieved by a simple solid state method, which will boost the practical application of LiMnPO4 cathode materials.


2021 ◽  
Vol 19 (11) ◽  
pp. 108-115
Author(s):  
Nihad Ali Shafeek

This research contains preparing the superconducting compound Bi2-xAgxSr2Ca2Cu3O10+δ and studying its structural and electrical characteristics. The samples were prepared using the solid-state method in two stages, and different concentrations of x were (x= 0.2,0.4,0.6,0.8) replaced instead of bismuth Bi. Then, using a hydraulic press 9 ton/cm2 and sintering with a temperature of 850°C, the samples were pressed. Next, x-ray diffraction is used to study the structural properties. The study of these samples was presented in different proportions of x values, where x = 0.4 is the best compensation ratio of x. A critical temperature of 1400C and the Tetragonal structure was got. After that, the effect of laser nidinium _ yak (Nd: YAG laser) was used on the compositional. It was found that the temperature value increased, so we got the best critical temperature, which is 142 0C.


Author(s):  
Adelyna Oktavia ◽  
Kurnia Sembiring ◽  
Slamet Priyono

Hospho-material of olivine, LiMnPO4 identified as promising for cathode material generation next Lithium-ion battery and has been successfully synthesized by solid-state method with Li2Co3, 2MnO2, 2NH4H2PO4 as raw material. The influence of initial concentration of precursors at kalsinasi temperatures (400-800 ° C) flows with nitrogen. The purity and composition phase verified by x-ray diffraction analysis (XRD), scanning electron microscopy (SEM), spectroscopy, energy Dispersive x-ray Analysis (EDS), Raman spectra. General investigation shows that there is a correlation between the concentration of precursors, the temperature and the temperature of sintering kalsinasi that can be exploited to design lithium-ion next generation.


2013 ◽  
Vol 591 ◽  
pp. 272-276
Author(s):  
Fang Zhang ◽  
Chao Song ◽  
Ling Li Ma ◽  
Xiao Li Xu ◽  
Zi Fei Peng

Sr2CeO4: Ho3+ was prepared by high-temperature solid-state method. The products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and photo luminescent (PL). The Sr2CeO4:Ho3+ phosphors showed a red emission under the near-ultraviolet excitation (280 nm) and the main emission centered at 475 nm. It has been found that A+ (A+ = Li+, Na+ or K+) codoped Sr2CeO4: Ho3+ phosphors could lead to a remarkable increase of photoluminescence. Luminous intensity was the highest when doping Li+ ions. Investigation indicated that Sr2Ce0.989O4: 0.001Ho3+, 0.01Li+ exhibited the strongest emission. The average particle size was about 6 um. The optimum sintering temperature was 1200 °C and the possible mechanism was also discussed.


2018 ◽  
Vol 20 (3) ◽  
pp. 15-19
Author(s):  
Guomin Li ◽  
Bing Wang ◽  
Rui Wang ◽  
Huiling Liu

Abstract Yb3+/Er3+/GZO ceramics have been synthesized with high temperature solid-state method. The phase and structure of the Yb3+/Er3+/GZO ceramics were characterized by X-ray diffraction (XRD). The XRD pattern that following ions Yb3+, Er3+ and Ga3+ were well doped into the ZnO lattice. Effi cient visible up-conversion (UC) red and green emission were observed under 980 nm excitation. The mechanism of the UC luminescence is investigated on the basis of the UC luminescence emission spectra, the power curve and energy level diagram. The infl uence of doping ions to the intensity ratio of red to green is analyzed and high purity of red light (red/green = 29.9) is fi nally obtained.


2021 ◽  
Author(s):  
Khmiri Ismail ◽  
Issa KRIAA ◽  
Hamadi KHEMAKHEM

Abstract The synthesis of (Ba 0.99 Ca 0.01 )(Zr 0.2 Ti 0.8 )O 3 (BCZT) and doped (Ba 0.99 Ca 0.01 )(Zr 0.2 Ti 0.8-x Mn x )O 3 (BCZT-xMn) ceramics was successfully carried out by the solid-state method. The doping effect is followed by X-ray powder diffraction, scanning electron microscopy (SEM), and dielectric and conductivity measurements. Indeed, X-ray diffraction measurements show the crystalline structure of ceramics. SEM images indicate the doping effect on the studied perovskite microstructure. The results indicate that during doping the maximum value of the temperature (Tm) of the dielectric constant varies slightly, and there will be a considerable decrease in permittivity, dielectric losses and conductivity. Manganese ions are well integrated in the perovskite while maintaining the solid solution.


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