Применение секционной матричной системы "ТОР ВМ" при восстановлении композиционными материалами полостей 2-го класса по Блэку

композиционные смолыматрицыэстетика в стоматологи

2020 roadmap on solid-state batteries

Li-ion batteries have revolutionized the portable electronics industry and empowered the electric vehicle (EV) revolution. Unfortunately, traditional Li-ion chemistry is approaching its physicochemical limit. The demand for higher density (longer range), high power (fast charging), and safer EVs has recently created a resurgence of interest in solid state batteries (SSB). Historically, research has focused on improving the ionic conductivity of solid electrolytes, yet ceramic solids now deliver sufficient ionic conductivity. The barriers lie within the interfaces between the electrolyte and the two electrodes, in the mechanical properties throughout the device, and in processing scalability. In 2017 the Faraday Institution, the UK's independent institute for electrochemical energy storage research, launched the SOLBAT (solid-state lithium metal anode battery) project, aimed at understanding the fundamental science underpinning the problems of SSBs, and recognising that the paucity of such understanding is the major barrier to progress. The purpose of this Roadmap is to present an overview of the fundamental challenges impeding the development of SSBs, the advances in science and technology necessary to understand the underlying science, and the multidisciplinary approach being taken by SOLBAT researchers in facing these challenges. It is our hope that this Roadmap will guide academia, industry, and funding agencies towards the further development of these batteries in the future

Advanced BaZrO3-BaCeO3 Based Proton Conductors Used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs)

In this thesis, the focus is on studying BaZrO3-BaCeO3 based proton conductors due to that they represent very promising proton conductors to be used for Intermediate Temperature Solid Oxide Fuel Cells (ITSOFCs). Here, dense BaZr0.5Ce0.3Y0.2O3-δ (BZCY532) ceramics were selected as the major studied materials. These ceramics were prepared by different sintering methods and doping strategies. Based on achieved results, the thesis work can simply be divided into the following parts: 1) An improved synthesis method, which included a water-based milling procedure followed by a freeze-drying post-processing, was presented. A lowered calcination and sintering temperature for a Hf0.7Y0.3O2-δ (YSH) compound was achieved. The value of the relative density in this work was higher than previously reported data. It is also concluded that this improved method can be used for mass-production of ceramics. 2) As the solid-state reactive sintering (SSRS) represent a cost-effective sintering method, the sintering behaviors of proton conductors BaZrxCe0.8-xLn0.2O3-δ (x = 0.8, 0.5, 0.1; Ln = Y, Sm, Gd, Dy) during the SSRS process were investigated. According to the obtained results, it was found that the sintering temperature will decrease, when the Ce content increases from 0 (BZCLn802) to 0.3 (BZCLn532) and 0.7 (BZCLn172). Moreover, the radii of the dopant ions similar to the radii of Zr4+ or Ce4+ ions show a better sinterability. This means that it is possible to obtain dense ceramics at a lower temperature. Moreover, the conductivities of dense BZCLn532 ceramics were determined. The conductivity data indicate that dense BZCY532 ceramics are good candidates as either oxygen ion conductors or proton conductors used for ITSOFCs. 3) The effect of NiO on the sintering behaviors, morphologies and conductivities of BZCY532 based electrolytes were systematically investigated. According to the achieved results, it can be concluded that the dense BZCY532B ceramics (NiO was added during ball-milling before a powder mixture calcination) show an enhanced oxygen and proton conductivity. Also, that BZCY532A (NiO was added after a powder mixture calcination) and BZCY532N (No NiO was added in the whole preparation procedures) showed lower values. In addition, dense BZCY532B and BZCY532N ceramics showed only small electronic conductivities, when the testing temperature was lower than 800 ℃. However, the BZCY532A ceramics revealed an obvious electronic conduction, when they were tested in the range of 600 ℃ to 800 ℃. Therefore, it is preferable to add the NiO powder during the BZCY532 powder preparation, which can lower the sintering temperature and also increase the conductivity. 4) Dense BZCY532 ceramics were successfully prepared by using the Spark Plasma Sintering (SPS) method at a temperature of 1350 ℃ with a holding time of 5 min. It was found that a lower sintering temperature (&lt; 1400 ℃) and a very fast cooling rate (&gt; 200 ℃/min) are two key parameters to prepare dense BZCY532 ceramics. These results confirm that the SPS technique represents a feasible and cost-effective sintering method to prepare dense Ce-containing BaZrO3-BaCeO3 based proton conductors. 5) Finally, a preliminary study for preparation of Ce0.8Sm0.2O2-δ (SDC) and BZCY532 basedcomposite electrolytes was carried out. The novel SDC-BZCY532 based composite electrolytes were prepared by using the powder mixing and co-sintering method. The sintering behaviors, morphologies and ionic conductivities of the composite electrolytes were investigated. The obtained results show that the composite electrolyte with a composition of 60SDC-40BZCY532 has the highest conductivity. In contrast, the composite electrolyte with a composition of 40SDC-60BZCY532 shows the lowest conductivity. In summary, the results show that BaZrO3-BaCeO3 based proton-conducting ceramic materials represent very promising materials for future ITSOFCs electrolyte applications.QC 20150423</p

Preparation of Potential Protonic Conductor Yttria Doped Hafnia by Using the Modified Solid State Reaction Method

A pure and well crystalized yttrium doped hafnium oxide Hf0.69Y0.31O2-δ (YSH) is obtained by using a modified solid state reaction method, where a water-based milling medium and freeze drying are implemented to reduce the agglomeration. The mean sizes of the YSH powder, which is obtained through a traditional alcohol-based milling method, is more than 1 um. However, the powder size can be reduced to 100 nm by using the water-based milling method. In addition, the calcination temperature can be lowered 200 °C to get a pure phase by using the water-based milling method, compared to the alcohol-based milling method. The relative density of YSH ceramic materials can reach to 97.5% by conventional sintering at 1650 °C after during 10 h.QC 20150422</p

Preparation of Protonic Conductor BaZr0.5Ce0.3Ln0.2O3-δ (Ln = Y, Sm, Gd, Dy) by using a Solid State Reactive Sintering Method

A pure and well crystalized yttrium doped hafnium oxide Hf0.69Y0.31O2-δ (YSH) is obtained by using a modified solid state reaction method, where a water-based milling medium and freeze drying are implemented to reduce the agglomeration. The mean sizes of the YSH powder, which is obtained through a traditional alcohol-based milling method, is more than 1 um. However, the powder size can be reduced to 100 nm by using the water-based milling method. In addition, the calcination temperature can be lowered 200 ℃ to get a pure phase by using the water-based milling method, compared to the alcohol-based milling method. The relative density of YSH ceramic materials can reach to 97.5% by conventional sintering at 1650 ℃ after during 10 h.QC 20150423</p

Al2O3-TiO2 composite oxide films on etched aluminum foil fabricated by electrodeposition and anodization

National Natural Science Foundation of China [21021002, 51072170]Ti species have been deposited on low-voltage etched aluminum foils by a simple electrochemical method using a Ti anode as Ti source in a Ti-free I-2-dissolved acetone solution. After annealing at 500-600 degrees C in air, an Al2O3-TiO2 composite oxide film was formed on the surface of the etched aluminum foil by anodizing galvanostatically in an ammonium adipate solution. The effects of I-2 concentration in the acetone solution, applied anode voltage, electrolysis time, and annealing temperature on the specific capacitance of the aluminum anode foils were investigated. The TiO2-deposited specimens prepared by applying a potential of 50 V for 3 min in 2.5 mM I-2-added acetone solution followed by annealing at 550 degrees C after anodization exhibited the highest specific capacitance, with an enhancement of 22% compared with pure etched aluminum foil specimens. The electro-deposition process and the change of the anode voltage during the anodization were analyzed

Electrophoresis Deposition of TiO2 Nanoparticles on Etched Aluminum Foil for Enhanced Specific Capacitance

National Natural Science Foundation of China [51072170, 21021002]We present a new approach to fabricate Al2O3-TiO2 composite oxide films on the low-voltage etched aluminum foils by integrating a facile electrophoresis deposition method, annealing post-treatment and anodization. The prepared Al2O3-TiO2 composite oxide films effectively increase the specific capacitance of the etched aluminum foils, resulting in a 20% enhancement compared with those using pure etched aluminum foils. Our approach demonstrates a new method to fabricate high specific capacitance composite oxide films on etched aluminum foils which will be ready for industrial application in aluminum electrolytic capacitors. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.013201esl] All rights reserved

Al(2)O(3)-TiO(2) composite oxide films on etched aluminum foil fabricated by electrodeposition and anodization

Ti species have been deposited on low-voltage etched aluminum foils by a simple electrochemical method using a Ti anode as Ti source in a Ti-free I(2)-dissolved acetone solution. After annealing at 500-600 degrees C in air, an Al(2)O(3)-TiO(2) composite oxide film was formed on the surface of the etched aluminum foil by anodizing galvanostatically in an ammonium adipate solution. The effects of I(2) concentration in the acetone solution, applied anode voltage, electrolysis time, and annealing temperature on the specific capacitance of the aluminum anode foils were investigated. The TiO(2)-deposited specimens prepared by applying a potential of 50 V for 3 min in 2.5 mM I(2)-added acetone solution followed by annealing at 550 degrees C after anodization exhibited the highest specific capacitance, with an enhancement of 22% compared with pure etched aluminum foil specimens. The electro-deposition process and the change of the anode voltage during the anodization were analyzed.National Natural Science Foundation of China[21021002, 51072170