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Increasing demand for green energy storage systems, arising from the rapid development of portable electronics, has triggered tremendous research efforts for designing new or high-performance electrodes. Herein, for the first time, we develop a graphene-wrapped CuCo2O4 hollow spheres electrodes with a 3D composite network, a high surface area of 106.2 m2 g−1 and nanopores mainly centred at 7.6 nm. This electrode exhibits excellent electrochemical performance with an ultrahigh specific capacitance of 1813 F g−1 at 2 A g−1 (3.63 F cm−2 at 4 mA cm−2) and a significant rate capability of 63% capacitance retention even at an ultrafast rate of 120 mA cm−2. Utilizing this nanocomposite as the positive electrode in a GW-CuCo2O4//rGO asy
Multilevel interior nanoporous CuCo2O4 microspheres have been for the first time developed using a facile self-templated method. Electrochemical results in three- and two-electrode systems show that the double-shelled hollow microsphere electrode is a promising candidate for high-performance supercapacitors.
In order to demonstrate the potential application of MN-CCP as a supercapacitor electrode, cyclic voltammetry (CV) and galvanostatic charge–discharge (CD) measurements were performed in a three-electrode cell containing a 3 M aqueous KOH electrolyte. Fig. 2a presents the typical CV curves of the electrode at various scan rates ranging from 5 to 50 mV s −1 . The appearance of strong redox peaks in the CV curves of the electrode, related to the faradaic redox reactions, indicates the pseudo-capacitive characteristics of the electrode. From the unchanged shape of the CVs, when the scan rate increases from 5 to 50 mV s −1 , it can be deduced that the electrode has a very good reversibility with improved mass transportation which ca
Hierarchical multi-shelled nanoporous mixed copper cobalt phosphide microspheres have been for the first time developed as a novel advanced electrode with superior electrochemical properties for high-performance asymmetric supercapacitors.
Thin fi lms and nanorods of Sn 1-xPb xS (0.00 ≤x≤0.45) with orthorhombic crystal structure and c-axis oriented perpendicular to the substrate surface were grown by hot wall vacuum deposition (HWVD) method. The nanorods grew via a self consuming vapor-liquid-solid (VLS) mechanism by means of Sn-droplets onto the surface of an underlying thin fi lm. The former one consists of stacked blocks with their c-axis always parallel to the growth direction. However, each block is alternately rotated around the [001] against its underlying and subsequent one. As revealed by composition analysis, there is no composition gradient across or within the nanorods and the underlying film. The rods were about 500 nm high and 250 nm in diameter. The droplet
It is demonstrated that the thickness and the electrical characteristics of thin insulator and metal films in layered structures can be determined from the reflection and transmission spectra of optical and microwave radiation interacting with these films. Measurements of the refractive index of SnO2 films in the range of thicknesses 40 nm to 2.8 μm and the electrical conductivity of Cr films deposited on ceramic substrates are reported.
The possibility to determine the thickness and electrophysical parameters of thin dielectric and metal films in sandwich-like structures using the results of measurement of reflection and transmission spectra in microwave and optical band are shown. The results of measurement of refractive index of SnO2 in the thickness range of 40 nm to 2800 nm and the results of measurement of conductivity of Cr-films applied to ceramic substrates are presented.
The study results are reported for a surface layer of a nickel base heat resistant alloy of the following composition, mas.%: Ni-8.2 Cr-10.5 W-15.5 Co-2.4 Mo-1.4 Nb-4.8 Al-0.2 C, after electroerosion. With the use of Rutherford and nuclear backscattering spectrometry and X-ray diffraction analysis it is revealed that melting under electroerosion results in redistribution of alloying elements, enrichment with carbon and occurrence of residual tensile stresses
Спектрометрия ядерного обратного рассеяния (ЯОР) протонов оперли 2-8 МэВ, обладая повышенной чувствительностью к С, N и О, является эффективным методом исследования двухкомпонентных карбидов, оксидов и нитридов В рамках модели однократного рассеяния (см например,/1/) парциальный энергетический спектр УЛ (Е) обратного рассеяния Ыопротонов первоначальной энер| ии Ео на угол# отдвухкомпонентной тшкинАуВ]. у опр
Спектрометрия ядерного обратного рассеяния (ЯОР) протонов энергии 2-8 МэВ, обладая повышенной чувствительностью к С, N и О, является эффективным методом исследования покрытий на основе карбидов, оксидов и нитридов В настоящей работе ЯОР протонов, наряду с методами оптической эмиссионной спектроскопии и рентгеновского анализа, использовали для исследования ТиЧ* покрытий на стальных пластинах Покрытия иано
Методами спектрометрии резерфордовского (ионы Не энергии 2 МэВ) и ядерного (протоны энергии 2 2 и 7 7 МэВ) обратного рассеяния, оптической эмиссионной спектроскопии в тлеющем разряде (1. ЕСО) и рентгеноструктурного анализа исследовали изменение химического и фазового состава, остаточных напряжений и параметров решетки в поверхностных слоях никелевого жаропрочного сплава N1-8, 2 Сг-10, 5 Ш-15, 5 Со-2, 4 Мо-1, 4 ЫЬ-4, 8 А1 (ма
Using a nondestructive chemical analysis with the help of spectrometry of 2-8 MeV proton backscattering and X-ray diffraction analysis a study is made into kinetic features of thermal diffusion nitriding (TDN) of armco-iron and titanium alloy VT1-0 in an ammonia environment. It is stated that VT1-0 TDN at 950 deg C results in a sharp weakening of an α-Ti basic texture, in formation of nontextured δ-TiN, tetragonal ε-Ti 2 N initially with (111) texture and then with (001) one, and an α-titanium diffusion zone. The variation of ε-Ti 2 N texture is due to the change of the orientation of α-titanium solid solution resulted from α→ β→ α polymorphous transformation at the nitriding temperature in accordance with orientation relations
Решение фундаментальных проблем в области современного материаловедения и поверхностной инженерии в значительной степени зависит от развития методов исследования поверхностных слоев материалов. В частности, актуальной задачей является разработка новых методов исследования процесса начальной стадии азотировании железа и других металлов и сплавов из-за большой трудоемкости методов химического пнплт
Термодиффузионное азотирование (ТДА) существенно повышает кислостойкость и износостойкость титана и титановых сплавов. Эффективным способом создания па мппсрхппсти титшгп пленок нитрида титлня служит метод ТДЛ п атмосфере пмми; 1Кп. Традиционными метоидми определения фазового состава, толщины слоев нитридов и диффузной зоны являются методы рентгеновской дифрактографии. В настоящей работе чти характе?