Preparation of LiFePO4/C composite powders by ultrasonic spray pyrolysis followed by heat treatment and their electrochemical properties

2008 ◽  
Vol 43 (12) ◽  
pp. 3305-3317 ◽  
Author(s):  
Muxina Konarova ◽  
Izumi Taniguchi
Keyword(s):  
Heat Treatment ◽  
Electrochemical Properties ◽  
Spray Pyrolysis ◽  
Ultrasonic Spray Pyrolysis ◽  
Composite Powders ◽  
Ultrasonic Spray

Physical and Electrochemical Properties of SiOx /C Composites Prepared by a Combination of Spray Pyrolysis and High Energy Ball Milling

2015 ◽  
Vol 1775 ◽  
pp. 7-12 ◽  
Author(s):  
Anara Molkenova ◽  
Izumi Taniguchi
Keyword(s):  
Electrochemical Properties ◽  
Spray Pyrolysis ◽  
Ball Milling ◽  
Ultrasonic Spray Pyrolysis ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Potential Range ◽  
Composite Powders ◽  
Ultrasonic Spray ◽  
Energy Ball

ABSTRACTSpray pyrolysis has been widely used to prepare homogeneous and uniform ceramic powders with high purity. In this study, we are proposing ultrasonic spray pyrolysis followed by heat treatment to produce SiOx/C composite powders, where sucrose was used as a carbon source. Furthermore, high energy ball milling of the as-prepared powders in the presence of acetylene black was conducted to activate its electrochemical properties by reducing the particle size and improving the functionalization of the SiOx composite particles. SiOx/C nanocomposite finally obtained at a sucrous concentration of 0.1 mol L-1 showed superior electrochemical properties, and the SiOx/C nanocomposite electrode delivered the first discharge and charge capacities of 1252 and 819 mAh g-1, respectively, with an initial columbic efficiency of 65% at a current density of 50 mAh g-1 in the potential range from 0.01 to 3 V versus Li/Li+.

Fabrication and Characterization of Various Calcium Phosphate Powders by Ultrasonic Spray Pyrolysis Technique

2006 ◽  
Vol 317-318 ◽  
pp. 57-60
Author(s):  
H.J. Wang ◽  
Young Keun Jeong ◽  
Kyung Sik Oh ◽  
B.H. Kim ◽  
Seong Hee Lee ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Calcium Phosphate ◽  
Spray Pyrolysis ◽  
Single Phase ◽  
Spray Pyrolysis Technique ◽  
Calcium Phosphates ◽  
Ultrasonic Spray Pyrolysis ◽  
Ultrasonic Spray Pyrolysis Technique ◽  
Starting Solution ◽  
Ultrasonic Spray

To overcome the difficulty of preparing the stoichiometric single phase calcium phosphate materials, ultrasonic spray pyrolysis was used to fabricate various calcium phosphates. Effect of the initial Ca/P ratios and pyrolysis temperature were investigated in preparation of single phase materials. Also thermal stability of the obtained powders was estimated with the heat treatment in the air. Crystallinity of the powders was analyzed using XRD and FT-IR. The HAp and β-TCP powders with single phase could be obtained from their stoichiometric Ca/P ratios of 1.50 and 1.67, respectively. These single phase powders with good crystallinity and stoichiometry were stable with respect to heat treatment up to 1000oC. The particle size of these powders would be controlled by the concentration of starting solution.

scholarly journals Photoluminescence and EPR spectrum of ZnO:Mn nanocrystals

2018 ◽  
Vol 26 (1) ◽  
pp. 69-72 ◽  
Author(s):  
O. V. Kovalenko ◽  
M. F. Bulaniy ◽  
V. Y. Vorovskiy ◽  
O. V. Khmelenko
Keyword(s):  
Heat Treatment ◽  
Spray Pyrolysis ◽  
Ultrasonic Spray Pyrolysis ◽  
Epr Spectra ◽  
Short Term ◽  
Epr Spectrum ◽  
Shell Surface ◽  
Admixture Concentration ◽  
Ultrasonic Spray ◽  
Nonequilibrium Conditions

Nanocrystals of ZnO:Mn were obtained by ultrasonic spray pyrolysis and had dimensions of d ~ 36 nm. The changes of photoluminescence end EPR spectra of these nanocrystals in dependence of Mn admixture concentration ( 2–8 at. %) and also at heat treatment in air during 1 hour at T = 850 ̊C were investigated. It is shown that under short-term (7–10 s) nonequilibrium conditions of ZnO:Mn nanocrystals forming, they consist of a nuclens and shell surface, in which, predominantly, the Mn admixture is concentrated. After annealing, the Mn admixture diffuses into the nucleus of a nanocrystal.

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