Magnetic Properties of YBaCuO Superconductors Fabricated Using Melt Growth

2019 ◽  
Vol 14 (12) ◽  
pp. 1660-1663
Author(s):  
Sang Heon Lee ◽  
Jin Hyuck Kim

YBa2Cu3O7–y (YBaCuO) superconductors used in energy storage devices are superconducting permanent magnets in bulk form. YBaCuO bulk superconductors are fabricated by interior seeded melt growth. Because the seed crystal growth is based on a slow diffusion reaction, long-term heat treatment is required to fabricate a single crystal in order to improve the magnetic properties of the bulk YBaCuO superconductor. We fabricated a single-grain bulk YBaCuO superconductor by controlling the distance between the seed and the upper surface of the YBaCuO bulk. The magnetic levitation force and trapped magnetic field were measured for the YBaCuO superconducting bulk. The correlation between the superconducting magnetic properties of the specimens and the microstructure of each crystallographic plane were evaluated.

Author(s):  
Marcin Krajewski ◽  
Mateusz Tokarczyk ◽  
Sabina Lewińska ◽  
Kamil Bochenek ◽  
Anna Ślawska-Waniewska

AbstractThis work presents the evolution of morphological, structural and magnetic properties of amorphous Fe-Ni wire-like nanochains caused by thermal oxidation. The initial Fe1−xNix samples (x = 0.75; 0.50; 0.25) were prepared through the magnetic-field-induced synthesis, and then they were heated in dry air at 400 °C and 500 °C. These treatments led to two competing simultaneous processes occurring in the investigated samples, i.e., (i) a conversion of amorphous material into crystalline material, and (ii) their oxidation. Both of them strictly affected the morphological and structural properties of the Fe-Ni nanochains which, in turn, were associated with the amount of iron in material. It was found that the Fe0.75Ni0.25 and Fe0.50Ni0.50 nanochains were covered during thermal treatment by the nanoparticle oxides. This coverage did not constitute a good barrier against oxidation, and these samples became more oxidized than the Fe0.25Ni0.75 sample which was covered by oxide nanosheets and contained additional Ni3B phase. The specific morphological evolutions of the Fe-Ni nanochains also influenced their saturation magnetizations, whereas their coercivities did not vary significantly. The obtained results constitute an important source of information for future application of the thermally treated Fe-Ni nanochains which could be applied in the energy storage devices or catalysis.


2013 ◽  
Vol 721 ◽  
pp. 278-281
Author(s):  
Jun Ma

t has been investigated that the interaction force in hybrid magnetic levitation systems with two GdBCO bulk superconductors and two permanent magnets system and a cubic permanent magnet (PM2) and a cubic permanent magnet (PM3) system in their coaxial configuration at liquid nitrogen temperature. The two single-domain GdBCO samples are of φ20mm and 10mm in thickness, the permanent magnet PM1 is of rectangular parallelepiped shape, the permanent magnets PM2 and PM3 are of cubic shape; the system placed on the middle of system and their coaxial configuration; It is found that the maximum levitation force decreases from 40.6N to 17.8N while the distance (Dpp) between the permanent magnets is increased from 0mm to 24mm and the distance (Dsp) between the two GdBCO bulk superconductors and a cubic permanent magnet PM3 is 0mm, The results indicate that the higher levitation force can be obtained by introducing PM-PM levitation system based on scientific and reasonable design of the hybrid magnetic levitation system, which is helpful for designing and constructing superconducting magnetic levitation systems.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mustafa H. Mustafa

AbstractSingle cell supercapacitors with electrodes of varying amounts of graphene and carbon black, formed via the electrospinning process with a carbon-based Polyacrylonitrile (PAN), were tested in 1M H2SO4. From the tested samples, the overall data indicates no correlation between impedance and capacitance energy values. However, the breakdown of the various samples showed mixed results of; good correlations between lower impedance resulting in higher and lower capacitance; while other samples showed higher impedance correlating to both higher and lower capacitance. No correlation was observed between the Impedance value and the thickness of the samples. Furthermore, carbon mole content was not a major factor in determining impedance; therefore, structure is not a major contributor to impedance. Whereas, carbon mole content is a major contributor to capacitance energy; Hence, impedance provides an alternative control point to increasing energy ( 2-10X times ), that can be retrofitted to existing systems, or to increase the energy storage beyond current levels by adjusting/controlling impedance in new designs. The data is indicating impedance is not constant and is varying. The mechanism of varying impedance is unclear and requires further research. However, it is thought to mimic the energy level and stability of matter (atoms). Therefore, impedance varies or oscillates accordingly to achieve an impedance level stability, and hence the term “Orbital Impedance Stability”. Thoughts into Impedance being an Energy Field, to be provided in next publication (In-sha’-ALLAH). This research is concluding that our conventional understanding of impedance is limited in scope. New approaches and further research is needed to better understand impedance behavior. A better understanding of impedance is essential to a breakthrough in energy storage devices from capacitors and batteries, to electric generation and distribution of energy, to magnetic levitation, medical drugs and other energy improvements.


2020 ◽  
Vol 13 (10) ◽  
pp. 3527-3535 ◽  
Author(s):  
Nana Chang ◽  
Tianyu Li ◽  
Rui Li ◽  
Shengnan Wang ◽  
Yanbin Yin ◽  
...  

A frigostable aqueous hybrid electrolyte enabled by the solvation interaction of Zn2+–EG is proposed for low-temperature zinc-based energy storage devices.


2003 ◽  
Vol 772 ◽  
Author(s):  
M. Schmid ◽  
C. Goze-Bac ◽  
M. Mehring ◽  
S. Roth ◽  
P. Bernier

AbstractLithium intercalted carbon nanotubes have attracted considerable interest as perspective components for energy storage devices. We performed 13C Nuclear Magnetic Resonance spin lattice relaxation measurements in a temperature range from 4 K up to 300 on alkali intercalated Single Walled Carbon Nanotubes in order to investigate the modifications of the electronic properties. The density of states at the Fermi level were determined for pristine, lithium and cesium intercalated carbon nanotubes and are discussed in terms of intercalation and charge transfer effects.


2020 ◽  
Author(s):  
Saneyuki Ohno ◽  
Tim Bernges ◽  
Johannes Buchheim ◽  
Marc Duchardt ◽  
Anna-Katharina Hatz ◽  
...  

<p>Owing to highly conductive solid ionic conductors, all-solid-state batteries attract significant attention as promising next-generation energy storage devices. A lot of research is invested in the search and optimization of solid electrolytes with higher ionic conductivity. However, a systematic study of an <i>interlaboratory reproducibility</i> of measured ionic conductivities and activation energies is missing, making the comparison of absolute values in literature challenging. In this study, we perform an uncertainty evaluation via a Round Robin approach using different Li-argyrodites exhibiting orders of magnitude different ionic conductivities as reference materials. Identical samples are distributed to different research laboratories and the conductivities and activation barriers are measured by impedance spectroscopy. The results show large ranges of up to 4.5 mScm<sup>-1</sup> in the measured total ionic conductivity (1.3 – 5.8 mScm<sup>-1</sup> for the highest conducting sample, relative standard deviation 35 – 50% across all samples) and up to 128 meV for the activation barriers (198 – 326 meV, relative standard deviation 5 – 15%, across all samples), presenting the necessity of a more rigorous methodology including further collaborations within the community and multiplicate measurements.</p>


2020 ◽  
Author(s):  
Yamin Zhang ◽  
Zhongpu Wang ◽  
Deping Li ◽  
Qing Sun ◽  
Kangrong Lai ◽  
...  

<p></p><p>Porous carbon has attracted extensive attentions as the electrode material for various energy storage devices considering its advantages like high theoretical capacitance/capacity, high conductivity, low cost and earth abundant inherence. However, there still exists some disadvantages limiting its further applications, such as the tedious fabrication process, limited metal-ion transport kinetics and undesired structure deformation at harsh electrochemical conditions. Herein, we report a facile strategy, with calcium gluconate firstly reported as the carbon source, to fabricate ultrathin porous carbon nanosheets. <a>The as-prepared Ca-900 electrode delivers excellent K-ion storage performance including high reversible capacity (430.7 mAh g<sup>-1</sup>), superior rate capability (154.8 mAh g<sup>-1</sup> at an ultrahigh current density of 5.0 A g<sup>-1</sup>) and ultra-stable long-term cycling stability (a high capacity retention ratio of ~81.2% after 4000 cycles at 1.0 A g<sup>-1</sup>). </a>Similarly, when being applied in Zn-ion capacitors, the Ca-900 electrode also exhibits an ultra-stable cycling performance with ~90.9% capacity retention after 4000 cycles at 1.0 A g<sup>-1</sup>, illuminating the applicable potentials. Moreover, the origin of the fast and smooth metal-ion storage is also revealed by carefully designed consecutive CV measurements. Overall, considering the facile preparation strategy, unique structure, application flexibility and in-depth mechanism investigations, this work will deepen the fundamental understandings and boost the commercialization of high-efficient energy storage devices like potassium-ion/sodium-ion batteries, zinc-ion batteries/capacitors and aluminum-ion batteries.</p><br><p></p>


2019 ◽  
Author(s):  
Saneyuki Ohno ◽  
Bianca Helm ◽  
Till Fuchs ◽  
Georg Dewald ◽  
Marvin Kraft ◽  
...  

<p>All-solid-state batteries are promising candidates for next-generation energy storage devices. Although the list of candidate materials for solid electrolytes has grown in the past decade, there are still many open questions concerning the mechanisms behind ionic migration in materials. In particular, the lithium thiophosphate family of materials has shown very promising properties for solid-state battery applications. Recently, the Ge-substituted Li<sub>6</sub>PS<sub>5</sub>I argyrodite was shown to be a very fast Li-ion conductor, despite the poor ionic conductivity of the unsubstituted Li<sub>6</sub>PS<sub>5</sub>I. Therein, the conductivity was enhanced by over three orders of magnitude due to the emergence of I<sup>−</sup>/S<sup>2−</sup>exchange, <i>i.e.</i>site-disorder, which led to a sudden decrease of the activation barrier with a concurrent flattening of the energy landscapes. Inspired by this work, two series of elemental substitutions in Li<sub>6+<i>x</i></sub>P<sub>1−<i>x</i></sub><i>M<sub>x</sub></i>S<sub>5</sub>I (<i>M</i>= Si and Sn) were investigated in this study and compared to the Ge-analogue. A sharp reduction in the activation energy was observed at the same <i>M</i><sup>4+</sup>/P<sup>5+</sup>composition as previously found in the Ge-analogue, suggesting a more general mechanism at play. Furthermore, structural analyses with X-ray and neutron diffraction indicate that similar changes in the Li-sublattice occur despite a significant variation in the size of the substituents, suggesting that in the argyrodites, the lithium substructure is most likely influenced by the occurring Li<sup>+</sup>– Li<sup>+</sup>interactions. This work provides further evidence that the energy landscape of ionic conductors can be tailored by inducing local disorder.</p>


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