New Battery Material by Powder Synthesis

2021 ◽  
Vol 70 (2) ◽  
pp. 30-33
Author(s):  
Viktor Drescher ◽  
Thomas Jähnert ◽  
Johannes Buchheim
2019 ◽  
Author(s):  
Kent Griffith ◽  
Clare Grey

Nb18W8O69 (9Nb2O5×8WO3) is the tungsten-rich end-member of the Wadsley–Roth crystallographic shear (cs) structures within the Nb2O5–WO3 series. It has the largest block size of any known, stable Wadsley–Roth phase, comprising 5 ´ 5 units of corner-shared MO6 octahedra between the shear planes, giving rise to 2 nm ´ 2 nm blocks. Rapid lithium intercalation is observed in this new candidate battery material and 7Li pulsed field gradient nuclear magnetic resonance spectroscopy – measured in a battery electrode for the first time at room temperature – reveals superionic lithium conductivity. In addition to its promising rate capability, Nb18W8O69 adds a piece to the larger picture of our understanding of high-performance Wadsley–Roth complex metal oxides.


2019 ◽  
Author(s):  
Timothée Stassin ◽  
Ivo Stassen ◽  
Joao Marreiros ◽  
Alexander John Cruz ◽  
Rhea Verbeke ◽  
...  

A simple solvent- and catalyst-free method is presented for the synthesis of the mesoporous metal-organic framework (MOF) MAF-6 (RHO-Zn(eIm)2) based on the reaction of ZnO with 2-ethylimidazole vapor at temperatures ≤ 100 °C. By translating this method to a chemical vapor deposition (CVD) protocol, mesoporous crystalline films could be deposited for the first time entirely from the vapor phase. A combination of PALS and Kr physisorption measurements confirmed the porosity of these MOF-CVD films and the size of the MAF-6 supercages (diam. ~2 nm), in close agreement with powder data and calculations. MAF-6 powders and films were further characterized by XRD, TGA, SEM, FTIR, PDF and EXAFS. The exceptional uptake capacity of the mesoporous MAF-6 in comparison to the microporous ZIF-8 is demonstrated by vapor-phase loading of a molecule larger than the ZIF-8 windows.


Author(s):  
Bernard Vancil ◽  
Charles Osborne ◽  
Allen Vancil ◽  
Wayne Ohlinger ◽  
Michael Green ◽  
...  
Keyword(s):  

2020 ◽  
Vol 32 (5) ◽  
pp. 1784-1793 ◽  
Author(s):  
Timothée Stassin ◽  
Ivo Stassen ◽  
João Marreiros ◽  
Alexander John Cruz ◽  
Rhea Verbeke ◽  
...  

2013 ◽  
Vol 334-335 ◽  
pp. 381-386 ◽  
Author(s):  
F. Arianpour ◽  
F. Kazemi ◽  
Hamid Reza Rezaie ◽  
A. Asjodi ◽  
J. Liu

Zirconium carbide (ZrC) has extended application in many ceramic and metal matrix composites especially used for ultra high temperature conditions. The synthesis of zirconium carbide powder is costly and difficult because of its high refractoriness and chemically inert properties. In this research, the synthesis of zirconium carbide nanopowder at low temperature via carbothermal reduction route was investigated according to thermodynamic data. The starting materials were zirconium acetate and sucrose as zirconium and carbon sources, respectively. After preparation of different carbon/zirconium ratio containing precursors, the dried precursors were heat treated at 1400°C and vacuum atmosphere. Also the ZrC formation was followed by thermal analysis of the produced precursors. The phase evolutions and microstructural studies were carried out using X-ray diffraction and scanning electron microscopy. The results showed that it is possible to synthesis zirconium carbide nanopowder with round shape and crystallite sizes smaller than 20 nm at low temperatures. Also according to thermodynamic calculations, it was concluded that by applying vacuum condition, the zirconium carbide formation can occur at less than 1000°C which is very effective on the size reducing of produced ZrC nanopowders.


2010 ◽  
Vol 660-661 ◽  
pp. 959-964
Author(s):  
Alexander Rodrigo Arakaki ◽  
Walter Kenji Yoshito ◽  
Valter Ussui ◽  
Dolores Ribeiro Ricci Lazar

One of the main applications of ceria-based (CeO2) ceramics is the manufacturing of Intermediate Temperature Solid Oxide Fuel Cells electrolytes. In order to improve ionic conductivity and densification of these materials various powder synthesis routes have been studied. In this work powders with composition Ce0.8(SmGd)0.2O1.9 have been synthesized by coprecipitation and hydrothermal treatment. A concentrate of rare earths containing 90wt% of CeO2 and other containing 51% of Sm2O3 and 30% of Gd2O3, both prepared from monazite processing, were used as precursor materials. The powders were characterized by X-ray diffraction, scanning and transmission electron microscopy, agglomerate size distribution by laser scattering and specific surface area by gas adsorption. Ceramic sinterability was evaluated by dilatometry and density measurements by Archimedes method. High specific surface area powders (~100m2/g) and cubic fluorite structure were obtained after hydrothermal treatment around 200°C. Ceramic densification was improved when compared to the one prepared from powders calcined at 800°C.


2007 ◽  
Vol 12 (4) ◽  
pp. 574-582 ◽  
Author(s):  
Nelson Heriberto de Almeida Camargo ◽  
O. J. Bellini ◽  
Enori Gemelli ◽  
M. Tomiyama

Nanostructured materials have been largely studied in the last few years because they have a great potential to applications in different fields like physics, chemistry, biology, mechanic and medicine. Synthesis and characterization of nanostructured materials is a subject of great interest involving science, market, politicians, government and society. The nanostructured materials are in demand in biomedical area, mainly the bioceramics composed of calcium phosphates (Ca/P), which have an excellent biocompatibility and mineralogical characteristics similar to those of bones. The aim of this work was to optimize the method of powder synthesis of nanostructured calcium phosphate and of nanocomposites composed of calcium phosphate//SiO2n, containing 5, 10 and 15% (in volume) of nanometric silica (SiO2n). The results are expressed according to the method of synthesis, mineralogical and morphological characterization, and thermal behavior for the different compositions of the nanostructured powder synthesized.


2007 ◽  
Vol 7 (11) ◽  
pp. 4061-4064 ◽  
Author(s):  
Sang-Jin Lee ◽  
Young-Soo Yoon ◽  
Myung-Hyun Lee ◽  
Nam-Sik Oh

The present research describes synthesis of highly sinterable, nano-sized hydroxyapatite (HAp) powders using a wet chemical route with recycled eggshell and phosphoric acid as calcium and phosphorous sources. The raw eggshell was easily turned to CaO by the calcining process, and phosphoric acid was mixed with the calcined eggshell by the wet, ball-milling method. The crystalline development and microstructures of the synthesized powders and sintered samples were examined by X-ray diffractometry and scanning electron microscopy, respectively. The observed phases on the powder synthesis process were dependent on the mixing ratio (wt%) of the calcined eggshell to phosphoric acid and the heating temperature. The ball-milled, nano-sized HAp powder, which has an average particle size of 70 nm, was fully densified at 1300 °C for 1h. The Ca/P ratio for stoichiometric composition of HAp was controlled by adjustment of the mixing ratio.


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