scholarly journals High‐Density Lignin‐Derived Carbon Nanofiber Supercapacitors with Enhanced Volumetric Energy Density (Adv. Sci. 17/2021)

2021 ◽  
Vol 8 (17) ◽  
pp. 2170109
Author(s):  
Servann Hérou ◽  
Josh J Bailey ◽  
Matt Kok ◽  
Philipp Schlee ◽  
Rhodri Jervis ◽  
...  
Keyword(s):  
Energy Density ◽  
Carbon Nanofiber ◽  
High Density

scholarly journals High‐Density Lignin‐Derived Carbon Nanofiber Supercapacitors with Enhanced Volumetric Energy Density

2021 ◽  
pp. 2100016
Author(s):  
Servann Hérou ◽  
Josh J Bailey ◽  
Matt Kok ◽  
Philipp Schlee ◽  
Rhodri Jervis ◽  
...  
Keyword(s):  
Energy Density ◽  
Carbon Nanofiber ◽  
High Density

scholarly journals A processing diagram for high-density Ti-6Al-4V by selective laser melting

2018 ◽  
Vol 24 (9) ◽  
pp. 1469-1478 ◽  
Author(s):  
Yinmin (Morris) Wang ◽  
Chandrika Kamath ◽  
Thomas Voisin ◽  
Zan Li
Keyword(s):  
Mechanical Properties ◽  
Energy Density ◽  
Processing Parameters ◽  
High Density ◽  
Low Density ◽  
Laser Powder Bed Fusion ◽  
Content Type ◽  
Powder Bed ◽  
Melt Pool ◽  
Hatch Spacing

Purpose Density optimization is the first critical step in building additively manufactured parts with high-quality and good mechanical properties. The authors developed an approach that combines simulations and experiments to identify processing parameters for high-density Ti-6Al-4V using the laser powder-bed-fusion technique. A processing diagram based on the normalized energy density concept is constructed, illustrating an optimized processing window for high- or low-density samples. Excellent mechanical properties are obtained for Ti-6Al-4V samples built from the optimized window. Design/methodology/approach The authors use simple, but approximate, simulations and selective experiments to design parameters for a limited set of single track experiments. The resulting melt-pool characteristics are then used to identify processing parameters for high-density pillars. A processing diagram is built and excellent mechanical properties are achieved in samples built from this window. Findings The authors find that the laser linear input energy has a much stronger effect on the melt-pool depth than the melt-pool width. A processing diagram based on normalized energy density and normalized hatch spacing was constructed, qualitatively indicating that high-density samples are produced in a region when 1 < E* < 2. The onset of void formation and low-density samples occur as E* moves beyond a value of 2. The as-built SLM Ti-6Al-4V shows excellent mechanical performance. Originality/value A combined approach of computer simulations and selected experiments is applied to optimize the density of Ti-6Al-4V, via laser powder-bed-fusion (L-PBF) technique. A series of high-density samples are achieved. Some special issues are identified for L-PBF processes of Ti-6Al-4V, including the powder particle sticking and part swelling issues. A processing diagram is constructed for Ti-6Al-4V, based on the normalized energy density and normalized hatch spacing concept. The diagram illustrates windows with high- and low-density samples. Good mechanical properties are achieved during tensile tests of near fully dense Ti-6Al-4V samples. These good properties are attributed to the success of density optimization processes.

scholarly journals Highly packed graphene–CNT films as electrodes for aqueous supercapacitors with high volumetric performance

2018 ◽  
Vol 6 (8) ◽  
pp. 3667-3673 ◽  
Author(s):  
Noel Díez ◽  
Cristina Botas ◽  
Roman Mysyk ◽  
Eider Goikolea ◽  
Teófilo Rojo ◽  
...  
Keyword(s):  
Energy Density ◽  
High Density ◽  
High Mass

Aqueous supercapacitors with high volumetric energy density are prepared using high mass, high density (1.5 g cm−3) electrodes of graphene–CNT composites.

scholarly journals Ultra-Stable Potassium Ion Storage of Nitrogen-Doped Carbon Nanofiber Derived from Bacterial Cellulose

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1130
Author(s):  
Liang Ma ◽  
Jinliang Li ◽  
Zhibin Li ◽  
Yingying Ji ◽  
Wenjie Mai ◽  
...  
Keyword(s):  
Energy Density ◽  
Bacterial Cellulose ◽  
Density Functional ◽  
Carbon Nanofiber ◽  
Specific Capacity ◽  
Relative Energy ◽  
Large Radius ◽  
Nitrogen Doped ◽  
Ion Storage ◽  
Nitrogen Doped Carbon

As a promising energy storage system, potassium (K) ion batteries (KIBs) have received extensive attention due to the abundance of potassium resource in the Earth’s crust and the similar properties of K to Li. However, the electrode always presents poor stability for K-ion storage due to the large radius of K-ions. In our work, we develop a nitrogen-doped carbon nanofiber (N-CNF) derived from bacterial cellulose by a simple pyrolysis process, which allows ultra-stable K-ion storage. Even at a large current density of 1 A g−1, our electrode exhibits a reversible specific capacity of 81 mAh g−1 after 3000 cycles for KIBs, with a capacity retention ratio of 71%. To investigate the electrochemical enhancement performance of our N-CNF, we provide the calculation results according to density functional theory, demonstrating that nitrogen doping in carbon is in favor of the K-ion adsorption during the potassiation process. This behavior will contribute to the enhancement of electrochemical performance for KIBs. In addition, our electrode exhibits a low voltage plateau during the potassiation–depotassiation process. To further evaluate this performance, we calculate the “relative energy density” for comparison. The results illustrate that our electrode presents a high “relative energy density”, indicating that our N-CNF is a promising anode material for KIBs.

Electrical and dielectric sensitivities to thermal processes in carbon nanofiber/high-density polyethylene composites

2011 ◽  
Vol 18 (1-2) ◽  
pp. 51-60 ◽  
Author(s):  
Tian Liu ◽  
Weston Wood ◽  
Bin Li ◽  
Brooks Lively ◽  
Wei-Hong Zhong
Keyword(s):  
Dielectric Properties ◽  
Thermal Treatment ◽  
High Density Polyethylene ◽  
Ac Conductivity ◽  
Elevated Temperatures ◽  
Carbon Nanofiber ◽  
Polymeric Materials ◽  
High Density ◽  
Heating Process ◽  
Thermal Processes

AbstractOwing to the huge interface region existing in a polymer nanocomposite, the effects of thermal processes on properties of nanocomposites are much more complicated than in a pure polymer. It is therefore important to determine the effects of thermal processes on nanocomposites with different interfacial interactions between the nanofillers and the polymer matrix. It is also important to explore the performance changes for nanocomposites under elevated temperatures over pure polymers. In this investigation, we examined the correlation of thermal treatment with dielectric properties of carbon nanofiber (CNF) reinforced high-density polyethylene nanocomposites. The thermal treatment of specimens was conducted for up to 120 h at 87°C and 127°C. Then, alternating current (AC) conductivity and dielectric properties were tested after definite intervals of time. Their changing rates over treatment time were analyzed. The results revealed the approximate linear relationships of AC conductivity and dielectric constant vs. heating time. Modified CNF reinforced nanocomposites had less influence by the heating treatments exhibiting better thermal resistance. The change rates of AC conductivity σ and dielectric properties have higher sensitivity to the treatment at a higher temperature. This study provides potential for further research on application of electrical and dielectric signals to detect the effects of heating process on lifetime of polymeric materials.

Co3O4 nanoparticles decorated carbon nanofiber mat as binder-free air-cathode for high performance rechargeable zinc-air batteries

Nanoscale ◽  
2015 ◽  
Vol 7 (5) ◽  
pp. 1830-1838 ◽  
Author(s):  
Bing Li ◽  
Xiaoming Ge ◽  
F. W. Thomas Goh ◽  
T. S. Andy Hor ◽  
Dongsheng Geng ◽  
...  
Keyword(s):  
Energy Density ◽  
Carbon Nanofibers ◽  
High Performance ◽  
Carbon Nanofiber ◽  
Rate Capability ◽  
Co3o4 Nanoparticles ◽  
Air Cathode ◽  
Free Air ◽  
Binder Free ◽  
Zinc Air Batteries

A facile method is developed for the fabrication of Co3O4 nanoparticles decorated carbon nanofibers, which enable significant improvement of rechargeable Zn-air batteries with respect to rate capability, cycling stability and energy density.

High-energy density nanofiber-based solid-state supercapacitors

2016 ◽  
Vol 4 (1) ◽  
pp. 160-166 ◽  
Author(s):  
Daniel W. Lawrence ◽  
Chau Tran ◽  
Arun T. Mallajoysula ◽  
Stephen K. Doorn ◽  
Aditya Mohite ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Solid State ◽  
Energy Density ◽  
Electric Double Layer ◽  
Carbon Nanofiber ◽  
High Energy ◽  
High Energy Density ◽  
Gel Electrolytes ◽  
Porous Carbon Nanofiber ◽  
Binder Free

We have developed binder-free solid-state electric double layer supercapacitors using freestanding porous carbon nanofiber electrodes fabricated using electrospinning and silica-based ionic liquid gel electrolytes.

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