High Energy Density, High Operating Frequency and Energy Efficient On-Chip Inductors based on Coiled Carbon Nanotubes (CCNTs)

2013 ◽  
Vol 1551 ◽  
pp. 41-46
Author(s):  
H. Faraby ◽  
P. R. Bandaru
Keyword(s):  
Carbon Nanotubes ◽  
High Energy ◽  
High Energy Density ◽  
Kinetic Inductance ◽  
Potential Candidate ◽  
Magnetic Inductance ◽  
Coiled Structure ◽  
Spiral Inductors ◽  
Material Volume ◽  
On Chip

ABSTRACTWe demonstrate the superior inductive properties of coiled carbon nanotubes (CCNTs) through numerical computation and analytical modeling, for the next generation of nanoscale, on-chip inductors. Taking advantage of the kinetic inductance (Lk), particularly evident at the nanoscale we find that the inductance can be increased by three orders of magnitude through changing the tube radius as well as the coil radius while the device footprint of the CCNTs can be reduced by 60%. By varying the geometric parameters of the coiled structure, the external magnetic inductance (LM,ext) can be as high as 20% of the Lk. We also report that the self resonant frequency (fSR) of CCNTs can be as much of the order of THz whereas the fSR of conventional copper(Cu) spiral inductors are limited to around 40GHz. Moreover when the material volume is considered, CCNTs have the potential to achieve Quality Factor (Q) eight times as Cu and when the footprint volume is considered Q can be twice as Cu All these promising properties of CCNTs make them a potential candidate for the entire frequency spectrum.

scholarly journals Confine sulfur in double-hollow carbon sphere integrated with carbon nanotubes for advanced lithium–sulfur batteries

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Maru Dessie Walle ◽  
You-Nian Liu
Keyword(s):  
Carbon Nanotubes ◽  
Coulombic Efficiency ◽  
Specific Capacity ◽  
High Energy ◽  
High Energy Density ◽  
Carbon Sphere ◽  
Hollow Carbon Sphere ◽  
Lithium Sulfur Batteries ◽  
Hollow Carbon ◽  
Lithium Sulfur

AbstractThe lithium–sulfur (Li–S) batteries are promising because of the high energy density, low cost, and natural abundance of sulfur material. Li–S batteries have suffered from severe capacity fading and poor cyclability, resulting in low sulfur utilization. Herein, S-DHCS/CNTs are synthesized by integration of a double-hollow carbon sphere (DHCS) with carbon nanotubes (CNTs), and the addition of sulfur in DHCS by melt impregnations. The proposed S-DHCS/CNTs can effectively confine sulfur and physically suppress the diffusion of polysulfides within the double-hollow structures. CNTs act as a conductive agent. S-DHCS/CNTs maintain the volume variations and accommodate high sulfur content 73 wt%. The designed S-DHCS/CNTs electrode with high sulfur loading (3.3 mg cm−2) and high areal capacity (5.6 mAh mg cm−2) shows a high initial specific capacity of 1709 mAh g−1 and maintains a reversible capacity of 730 mAh g−1 after 48 cycles at 0.2 C with high coulombic efficiency (100%). This work offers a fascinating strategy to design carbon-based material for high-performance lithium–sulfur batteries.

scholarly journals Electrochemical Performance Improvement of the Catalyst of the Methanol Micro-Fuel Cell Using Carbon Nanotubes

2019 ◽  
Author(s):  
Mohammad Kazemi Nasrabadi ◽  
Amir Ebrahimi-Moghadam ◽  
Mohammad Hosein Ahmadi ◽  
Ravinder Kumar ◽  
Narjes Nabipour
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Carbon Black ◽  
Oxidation Reaction ◽  
High Energy ◽  
Proton Exchange ◽  
Operating Conditions ◽  
High Energy Density ◽  
Methanol Oxidation Reaction

Due to low working temperature, high energy density and low pollution, proton exchange fuel cells have been investigated under different operating conditions in different applications. Using platinum catalysts in methanol fuel cells leads to increasing the cost of this kind of fuel cell which is considered as a barrier to the commercialism of this technology. For this reason, a lot of efforts have been made to reduce the loading of the catalyst required on different supports. In this study, carbon black (CB) and carbon nanotubes (CNT) have been used as catalyst supports of the fuel cell as well as using the double-metal combination of platinum-ruthenium (PtRu) as anode electrode catalyst and platinum (Pt) as cathode electrode catalyst. The performance of these two types of electro-catalyst in the oxidation reaction of methanol has been compared based on electrochemical tests. Results showed that the carbon nanotubes increase the performance of the micro-fuel cell by 37% at maximum power density, compared to the carbon black. Based on thee-electrode tests of chronoamperometry and voltammetry, it was found that the oxidation onset potential of methanol for CNT has been around 20% less than CB, leading to the kinetic improvement of the oxidation reaction. The current density of methanol oxidation reaction increased up to 62% in CNT sample compared to CB supported one, therefore the active electrochemical surface area of the catalyst has been increased up to 90% by using CNT compared to CB which shows the significant rise of the electrocatalytic activity in CNT supported catalyst. Moreover, the resistance of the CNT supported sample to poisonous intermediate species has been found 3% more than CB supported one. According to the chronoamperometry test results, it was concluded that the performance and sustainability of the CNT electro-catalyst show remarkable improvement compared to CB electro-catalyst in the long term.

scholarly journals Facile synthesis of carbon nanotube-supported NiO//Fe2O3 for all-solid-state supercapacitors

2019 ◽  
Vol 10 ◽  
pp. 1923-1932 ◽  
Author(s):  
Shengming Zhang ◽  
Xuhui Wang ◽  
Yan Li ◽  
Xuemei Mu ◽  
Yaxiong Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Solid State ◽  
Metal Oxides ◽  
Reduction Method ◽  
High Capacity ◽  
Rate Capability ◽  
High Energy ◽  
High Energy Density ◽  
Carbon Cloth

We have successfully prepared iron oxide and nickel oxide on carbon nanotubes on carbon cloth for the use in supercapacitors via a simple aqueous reduction method. The obtained carbon cloth–carbon nanotube@metal oxide (CC-CNT@MO) three-dimensional structures combine the high specific capacitance and rich redox sites of metal oxides with the large specific area and high electrical conductivity of carbon nanotubes. The prepared CC-CNT@Fe2O3 anode reaches a high capacity of 226 mAh·g−1 at 2 A·g−1 with a capacitance retention of 40% at 40 A·g−1. The obtained CC-CNT@NiO cathode exhibits a high capacity of 527 mAh·g−1 at 2 A·g−1 and an excellent rate capability with a capacitance retention of 78% even at 40 A·g−1. The all-solid-state asymmetric supercapacitor fabricated with these two electrodes delivers a high energy density of 63.3 Wh·kg−1 at 1.6 kW·kg−1 and retains 83% of its initial capacitance after 5000 cycles. These results demonstrate that our simple aqueous reduction method to combine CNT and metal oxides reveals an exciting future in constructing high-performance supercapacitors.

On the Use of Carbon Nanotubes in Prototyping the High Energy Density Li‐ion Batteries

2020 ◽  
Vol 8 (6) ◽  
pp. 2000146 ◽  
Author(s):  
Filipp Napolskiy ◽  
Mikhail Avdeev ◽  
Meir Yerdauletov ◽  
Oleksandr Ivankov ◽  
Svetlana Bocharova ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Energy Density ◽  
High Energy ◽  
High Energy Density ◽  
Li Ion Batteries ◽  
Li Ion
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