scholarly journals Porous Structure of Cylindrical Particle Compacts

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1498
Author(s):  
Aidana Boribayeva ◽  
Gulfairuz Iniyatova ◽  
Aruzhan Uringaliyeva ◽  
Boris Golman
Keyword(s):  
Voronoi Tessellation ◽  
Spherical Particles ◽  
Energy Storage Devices ◽  
Voronoi Cells ◽  
Storage Devices ◽  
Aspect Ratios ◽  
Loose Packing ◽  
Porous Microstructure ◽  
Porous Compacts ◽  
Cylindrical Particles

The porous compacts of non-spherical particles are frequently used in energy storage devices and other advanced applications. In the present work, the microstructures of compacts of monodisperse cylindrical particles are investigated. The cylindrical particles with various aspect ratios are generated using superquadrics, and the discrete element method was adopted to simulate the compacts formed under gravity deposition of randomly oriented particles. The Voronoi tessellation is then used to quantify the porous microstructure of compacts. With one exception, the median reduced free volume of Voronoi cells increases, and the median local packing density decreases for compacts composed of cylinders with a high aspect ratio, indicating a loose packing of long cylinders due to their mechanical interlocking during compaction. The obtained data are needed for further optimization of compact porous microstructure to improve the transport properties of compacts of non-spherical particles.

scholarly journals Stretchable Supercapacitors Based on Carbon Nanotubes-Deposited Rubber Polymer Nanofibers Electrodes with High Tolerance against Strain

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 541 ◽  
Author(s):  
Juyeon Yoon ◽  
Joonhyung Lee ◽  
Jaehyun Hur
Keyword(s):  
Sheet Resistance ◽  
Electromechanical Properties ◽  
Energy Storage Devices ◽  
Water Contact ◽  
Storage Devices ◽  
Uniform Coating ◽  
Aspect Ratios ◽  
Volumetric Capacitance ◽  
Surfactant Assisted ◽  
Deposition Conditions

We report a new fabrication method for a fully stretchable supercapacitor based on single wall carbon nanotube (SWCNT)-coated electrospun rubber nanofibers as stretchable supercapacitor electrodes. The deposition conditions of SWCNT on hydrophobic rubber nanofibers are experimentally optimized to induce a uniform coating of SWCNT. For surfactant-assisted coating of SWCNT, both water contact angle and sheet resistance were lower compared to the cases with other surface treatment methods, indicating a more effective coating approach. The excellent electromechanical properties of this electrode under stretching conditions are demonstrated by the measurement of Young’s modulus and normalized sheet resistance. The superb tolerance of the electrode with respect to stretching is the result of (i) high aspect ratios of both nanofiber templates and the SWCNT conductors, (ii) the highly elastic nature of rubbery nanofibers, and (iii) the strong adherence of SWCNT-coated nanofibers on the elastic ecoflex substrate. Electrochemical and electromechanical measurements on stretchable supercapacitor devices reveal that the volumetric capacitance (15.2 F cm−3 at 0.021 A cm−3) of the unstretched state is maintained for strains of up to 40%. At this level of strain, the capacitance after 1,000 charge/discharge cycles was not significantly reduced. The high stability of our stretchable device suggests potential future applications in various types of wearable energy storage devices.

scholarly journals Stretchable Supercapacitors Based on Carbon Nanotubes-Deposited Rubber Polymer Nanofibers Electrode with High Tolerance against Strain

2018 ◽  
Author(s):  
Juyeon Yoon ◽  
Joonhyung Lee ◽  
Jaehyun Hur
Keyword(s):  
Sheet Resistance ◽  
Electromechanical Properties ◽  
Energy Storage Devices ◽  
Water Contact ◽  
Storage Devices ◽  
Uniform Coating ◽  
Aspect Ratios ◽  
Volumetric Capacitance ◽  
Surfactant Assisted ◽  
Deposition Conditions

We report a new fabrication method for a fully stretchable supercapacitor based on single wall carbon nanotube (SWCNT)-coated electrospun rubber nanofibers as stretchable supercapacitor electrodes. The deposition conditions of SWCNT on hydrophobic rubber nanofibers are experimentally optimized to induce a uniform coating of SWCNT. For surfactant-assisted coating of SWCNT, both water contact angle and sheet resistance were the lowest compared to the cases with other surface treatment methods, indicating the most effective coating approach. The excellent electromechanical properties of this electrode under the stretching condition is demonstrated by the measurement of Young’s modulus and normalized sheet resistance. This superb tolerance of the electrode with respect to stretching results from i) high aspect ratios of both nanofiber templates and the SWCNT conductors, ii) highly elastic nature of rubbery nanofiber, and iii) strong adherence of SWCNT-coated nanofiber on the elastic ecoflex substrate. Electrochemical and electromechanical measurements on the stretchable supercapacitor devices reveal that the volumetric capacitance (15.2 F cm-3 at 0.021 A cm-3) of the unstretched state is maintained for strains of up to 40 %. At this level of strain, the capacitance after 1,000 charge/discharge cycles is not significantly reduced. The high stability of our stretchable device suggests potential future applications in various types of wearable energy storage devices.

An aqueous hybrid electrolyte for low-temperature zinc-based energy storage devices

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

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

NMR studies of alkali intercalted carbon nanotubes

2003 ◽  
Vol 772 ◽  
Author(s):  
M. Schmid ◽  
C. Goze-Bac ◽  
M. Mehring ◽  
S. Roth ◽  
P. Bernier
Keyword(s):  
Carbon Nanotubes ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Energy Storage Devices ◽  
Nmr Studies ◽  
Storage Devices ◽  
Spin Lattice ◽  
Relaxation Measurements ◽  
Resonance Spin ◽  
Walled Carbon Nanotubes

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.

How Certain Are the Reported Ionic Conductivities of Thiophosphate-Based Solid Electrolytes? an Interlaboratory Study

2020 ◽  
Author(s):  
Saneyuki Ohno ◽  
Tim Bernges ◽  
Johannes Buchheim ◽  
Marc Duchardt ◽  
Anna-Katharina Hatz ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Ionic Conductivity ◽  
Relative Standard Deviation ◽  
Solid Electrolytes ◽  
Ionic Conductivities ◽  
Ionic Conductors ◽  
Energy Storage Devices ◽  
Activation Barriers ◽  
Storage Devices ◽  
Relative Standard

<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>

Ultrathin Carbon Nanosheets for Highly-efficient Capacitive K-ion and Zn-ion Storage

2020 ◽  
Author(s):  
Yamin Zhang ◽  
Zhongpu Wang ◽  
Deping Li ◽  
Qing Sun ◽  
Kangrong Lai ◽  
...  
Keyword(s):  
Energy Storage ◽  
Porous Carbon ◽  
Metal Ion ◽  
Rate Capability ◽  
Energy Storage Devices ◽  
Capacity Retention ◽  
Carbon Nanosheets ◽  
Storage Devices ◽  
High Efficient ◽  
Ion Storage

<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>

Further Evidence for Energy Landscape Flattening in the Superionic Argyrodites Li6+xP1−xMxS5I (M = Si, Ge, Sn)

2019 ◽  
Author(s):  
Saneyuki Ohno ◽  
Bianca Helm ◽  
Till Fuchs ◽  
Georg Dewald ◽  
Marvin Kraft ◽  
...  
Keyword(s):  
Solid State ◽  
Activation Barrier ◽  
Energy Landscape ◽  
General Mechanism ◽  
Ionic Conductors ◽  
Energy Storage Devices ◽  
Ion Conductor ◽  
Storage Devices ◽  
Open Questions ◽  
Sudden Decrease

<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>

Carbothermal conversion of boric acid into boron-oxy-carbide nanostructures for high-power supercapacitors

2021 ◽  
Author(s):  
Dhanasekar Kesavan ◽  
Vimal Kumar Mariappan ◽  
Karthikeyan Krishnamoorthy ◽  
Sang-Jae Kim
Keyword(s):  
Energy Storage ◽  
Boric Acid ◽  
High Power ◽  
Electrochemical Energy Storage ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Carbothermal Method ◽  
Electrochemical Energy

In this study, we report a facile carbothermal method for the preparation of boron-oxy-carbide (BOC) nanostructures and explore their properties towards electrochemical energy storage devices.

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