scholarly journals Nanostructured materials based on the bronze titanium dioxide for lithium batteries in large-sized engineering

Author(s):  
Д.П. Опра ◽  
С.В. Гнеденков ◽  
С.Л. Синебрюхов ◽  
А.А. Соколов ◽  
К.П. Опра ◽  
...  

В последние годы, стремительными темпами развивается целый ряд направлений промышленности, таких как гибридный и электрический автотранспорт, подводная робототехника, сфера бесперебойного энергообеспечения, прибрежная возобновляемая энергетика, и т.п., требующих от автономных накопителей энергии работы в жёстких условиях эксплуатации. Это диктует необходимость решения ряда задач, связанных с получением для них функциональных материалов с достаточно высокими удельными характеристиками, способностью стабильно и безопасно функционировать в широком температурном диапазоне и в условиях ускоренного заряда. В этой связи все больше внимания исследователями уделяется диоксиду титана. В рамках настоящего исследования получены наноленты диоксида титана со структурой бронз гидротермальным способом с использованием анатаза, состоящего из частиц различного размера. Обнаружено, что степень кристалличности и текстурные характеристики формирующегося TiO2-B определяются размером частиц и площадью поверхности стартового реагента. В свою очередь оба эти фактора оказывают значительное влияние на электрохимические характеристики бронзовой модификации TiO2: после 35 циклов заряда/разряда емкость составила 203 мА∙ч/г, а скорость деградации – 0,25% за цикл для материала, синтезированного из анатаза с размером частиц ~30 нм и площадью поверхности ~100 м2/г. В то же время образцы, полученные с использованием более крупных частиц, показывают худшие показатели емкости и циклируемости. Now, technology progress provides broad prerequisites for practical usage of batteries in the field of hybrid and electric vehicles, marine robotics, backup uninterruptible power supplies, coastal renewable energy sources, etc. with a more hard-working performance. This dictates the necessity of development an advanced electrode materials with a sufficiently high specific parameters, stability of operation and safely in a wide temperature range and under fast charge mode. In this way, a more attention has been paid to titanium dioxide. Herein, the titanium dioxide nanobelts with a bronze structure were obtained by the hydrothermal method using anatase with different particle size as a precursor. It was found that the degree of crystallinity and textural characteristics of as-formed TiO2-B are determined by the particle size and surface area of starting reagent. Both of these factors have a benefit effect on the electrochemical performance of TiO2-B: the capacity of 203 mA·h/g was registered after 35 charge/discharge cycles with a degradation of 0.25% per cycle for material synthesized from anatase with a particle size about ~30 nm (~100 m2/g). On the other hand, the samples prepared from a precursors with larger particles show the worst capacity and cyclability.

2005 ◽  
Vol 475-479 ◽  
pp. 2403-2406 ◽  
Author(s):  
Sang Mok Lee ◽  
Hoon Jae Park ◽  
Seung Soo Kim ◽  
Tae Hoon Choi ◽  
E.Z. Kim ◽  
...  

Reducing the particle size of drug materials down to submicron is an important matter in pharmaceutical industry. Cryogenic milling technology is one of the mechanical milling processes, which is mostly utilized in refining grain size of metal and ceramics at extremely low temperature environment. This technique has not been readily studied in application to medical and biotechnology. This paper, therefore, describes the application of cryogenic milling process to reduce particle size of Ibuprofen. The shape and size of the Ibuprofen particle before and after the cryogenic ball milling process were analyzed. XRD analysis was performed to examine a change in crystallinity of Ibuprofen by the cryogenic ball milling process. The results showed that the size of Ibuprofen particles was reduced to 1/10 or less of its initial size. The results also showed that the degree of crystallinity of Ibuprofen was slightly reduced after cryogenic ball milling with nitrogen.


2013 ◽  
Vol 860-863 ◽  
pp. 1017-1020
Author(s):  
Hai Zhao ◽  
Jun Qing Liu

Fe-Mn metal oxides nanosized particles have been prepared by doping with La. The effects of promoters on the oxides were investigated by XRD, BET and other methods. XRD results revealed that the degree of crystallinity and particle size of mixed oxide phase decreased due to doping with La2O3. Addition of La led to a progressive increase in the surface area of the sample. Tests showed that the addition of 3 wt % La2O3 greatly improved the absorption sulfur capacity of the sorbent for COS removal. Keywords: Hydrogen utilized; Carbonyl Sulfide; Doping; La2O3


Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 240
Author(s):  
Vladimir Kotlyar ◽  
Victoria Pishchulina ◽  
Alexey N. Beskopylny ◽  
Besarion Meskhi ◽  
Yury Popov ◽  
...  

Determining the age of ancient architectural and cultural monuments is a significant scientific problem. An approach based on the transformation of portlandite into calcite and subsequent recrystallization of calcite is considered, which allows for estimating the relative age of ancient brickworks for local groups of historic buildings based on the results of diffraction studies of powder samples of carbonate mortars and measurements of samples with a known age. This article presents the results of the study of lime mortars of ancient brickwork. Under natural conditions, the process of transformation of portlandite into calcite takes from 100 to 200 years. The rate of this process is influenced by temperature, humidity, peculiarities of interaction with carbon dioxide contained in the air, etc. Examples show that portlandite is completely transformed into calcite in masonry mortars of the 18th century and that portlandite is not found in older mortars. It was determined that after the transformation of portlandite into calcite, an increase in the degree of recrystallization of calcite is observed, which manifests itself in powder diffraction patterns in the relative broadening of the diffraction peak of calcite hkl 104. In a detailed study, an estimate of the peak width at half maximum (FWHM) associated with the degree of crystallinity is effective. The actual data are given, which show that in older lime mortars the degree of recrystallization of calcite is higher than in younger ones. This fact makes it possible to indirectly determine the relative age of brickwork and masonry of various buildings of architectural heritage, which is especially relevant for the objects with the use of lime mortars of the northern provinces of the Byzantine Oecumene and other periods of various cultures.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3523
Author(s):  
Radosław Krzosa ◽  
Łukasz Makowski ◽  
Wojciech Orciuch ◽  
Radosław Adamek

The deagglomeration of titanium-dioxide powder in water suspension performed in a stirring tank was investigated. Owing to the widespread applications of the deagglomeration process and titanium dioxide powder, new, more efficient devices and methods of predicting the process result are highly needed. A brief literature review of the application process, the device used, and process mechanism is presented herein. In the experiments, deagglomeration of the titanium dioxide suspension was performed. The change in particle size distribution in time was investigated for different impeller geometries and rotational speeds. The modification of impeller geometry allowed the improvement of the process of solid particle breakage. In the modelling part, numerical simulations of the chosen impeller geometries were performed using computational-fluid-dynamics (CFD) methods whereby the flow field, hydrodynamic stresses, and other useful parameters were calculated. Finally, based on the simulation results, the population-balance with a mechanistic model of suspension flow was developed. Model predictions of the change in particle size showed good agreement with the experimental data. Using the presented method in the process design allowed the prediction of the product size and the comparison of the efficiency of different impeller geometries.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Sangmo Kim ◽  
Thi My Huyen Nguyen ◽  
Rui He ◽  
Chung Wung Bark

AbstractPiezoelectric nanogenerators (PNGs) have been studied as renewable energy sources. PNGs consisting of organic piezoelectric materials such as poly(vinylidene fluoride) (PVDF) containing oxide complex powder have attracted much attention for their stretchable and high-performance energy conversion. In this study, we prepared a PNG combined with PVDF and lanthanum-modified bismuth titanate (Bi4−XLaXTi3O12, BLT) ceramics as representative ferroelectric materials. The inserted BLT powder was treated by high-speed ball milling and its particle size reduced to the nanoscale. We also investigated the effect of particle size on the energy-harvesting performance of PNG without polling. As a result, nano-sized powder has a much larger surface area than micro-sized powder and is uniformly distributed inside the PNG. Moreover, nano-sized powder-mixed PNG generated higher power energy (> 4 times) than the PNG inserted micro-sized powder.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Emi Govorčin Bajsić ◽  
Vesna Rek ◽  
Ivana Ćosić

The effect of the addition of talc on the morphology and thermal properties of blends of thermoplastic polyurethane (TPU) and polypropylene (PP) was investigated. The blends of TPU and PP are incompatible because of large differences in polarities between the nonpolar crystalline PP and polar TPU and high interfacial tensions. The interaction between TPU and PP can be improved by using talc as reinforcing filler. The morphology was observed by means of scanning electron microscopy (SEM). The thermal properties of the neat polymers and unfilled and talc filled TPU/PP blends were studied by using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The addition of talc in TPU/PP blends improved miscibility in all investigated TPU/T/PP blends. The DSC results for talc filled TPU/PP blends show that the degree of crystallinity increased, which is due to the nucleating effect induced by talc particles. The reason for the increased storage modulus of blends with the incorporation of talc is due to the improved interface between polymers and filler. According to TGA results, the addition of talc enhanced thermal stability. The homogeneity of the talc filled TPU/PP blends is better than unfilled TPU/PP blends.


2013 ◽  
Vol 864-867 ◽  
pp. 751-754 ◽  
Author(s):  
Andrey Askadskii ◽  
Marina Popova ◽  
Tatyana Matseevich ◽  
Elena Kurskaya

The influence of the degree of crystallinity of polymers on the glass transition temperature Tg of their amorphous domains is quantitatively analyzed. The analysis is made based on the Mandelkerns ideas [ concerning the restrictive effect of crystallization on the mobility of macromolecules within the amorphous domains. At low degrees of crystallinity, Tg of amorphous domains slowly increases, and then increases much faster at high degrees of crystallinity.


Sign in / Sign up

Export Citation Format

Share Document