Stability and Performance of Heterogeneous Anode Assemblies of Silicon Nanowires on Carbon Meshes for Lithium-Sulfur Battery Applications

2015 ◽  
Vol 1751 ◽  
Author(s):  
Andreas Krause ◽  
Jan Brueckner ◽  
Susanne Doerfler ◽  
Florian M. Wisser ◽  
Holger Althues ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Volume Expansion ◽  
Specific Capacity ◽  
Current Collector ◽  
Si Nanowires ◽  
Free Standing ◽  
Fiber Network ◽  
And Performance ◽  
Sulfur Battery ◽  
Full Charge

ABSTRACTSi is a promising anode material for Li storage due to its high theoretical specific capacity surpassing 4200 Ah/kg. Si based anodes exhibit an extreme instability upon electrochemical incorporation of Li given the accompanied large volume expansion of about 400%. We show innovative anode assemblies composed of a forest of free standing Si nanowires conformally integrated on carbon meshes. The morphology of silicon nanowires allows a volume expansion and compression lowering strain incorporation. In this paper, we demonstrate the utilization of SiNW grown on top of a current collector made of a carbon fiber network. This leads to an increase of stability of Si with a remaining effective capacitance above 2000 Ah/kg(Si) after 225 full charge/discharge cycles. This is significantly better compared to previous results shown in literature. The anodes are fabricated by a simple and inexpensive method promising for a transfer into industrial integration.

Aqueous Processed Ni-Rich Li(Ni0.8Co0.1Mn0.1)O2 Cathodes Along with Water-Based Binders and a Carbon Fabric as 3-D Conductive Host

2021 ◽  
Author(s):  
Pedaballi Sireesha ◽  
Chia-Chen Li
Keyword(s):  
Electrode Materials ◽  
Discharge Rate ◽  
Specific Capacity ◽  
Three Dimensional ◽  
Current Collector ◽  
Carbon Fabric ◽  
Fiber Network ◽  
Uniform Dispersion ◽  
Water Based ◽  
Lower Impedance

Abstract A carbon fabric with three-dimensional carbon fiber network is proposed as a conductive framework instead of Al current collector, in order to fabricate a LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode using an environmentally friendly water-based process. Water-based NCM811 slurries prepared without binder, with poly(acrylic acid) (PAA) binder, and with poly(acrylonitrile) (PAN) binder have the equilibrium pH values of 12.4, 6.7, and 12.6, respectively. Without a binder, the cathode materials are poorly dispersed in the slurry, which hinders smooth casting on the carbon fabric. The addition of either PAA or PAN improves the uniform dispersion of particles and the loading capability of slurries, leading to a lower impedance of the cast cathodes. Compared to PAA, PAN performs better with the carbon fabric as a conductive framework, due to the better dispersion of electrode materials, lower impedance in the fabricated electrode, and good chemical stability of PAN to the electrolyte. The cell constructed with PAN-added cathode exhibits a high specific capacity of 150–160 mAh g-1 at a charge/discharge rate of 0.5C, and nearly 100% capacity retention after 100 cycles. Nevertheless, PAA is soluble in the electrolyte and has some negative effects on the capacity performance of the constructed cell.

scholarly journals Switched Capacitor DC-DC Converters: A Survey on the Main Topologies, Design Characteristics, and Applications

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2231
Author(s):  
Alencar Franco de Souza ◽  
Fernando Lessa Tofoli ◽  
Enio Roberto Ribeiro
Keyword(s):  
Voltage Regulation ◽  
Inherent Difficulty ◽  
Practical Applications ◽  
Dc Power ◽  
Higher Power ◽  
Voltage Doubler ◽  
Converter Design ◽  
Design Characteristics ◽  
And Performance ◽  
Full Charge

This work presents a review of the main topologies of switched capacitors (SCs) used in DC-DC power conversion. Initially, the basic configurations are analyzed, that is, voltage doubler, series-parallel, Dickson, Fibonacci, and ladder. Some aspects regarding the choice of semiconductors and capacitors used in the circuits are addressed, as well their impact on the converter behavior. The operation of the structures in terms of full charge, partial charge, and no charge conditions is investigated. It is worth mentioning that these aspects directly influence the converter design and performance in terms of efficiency. Since voltage regulation is an inherent difficulty with SC converters, some control methods are presented for this purpose. Finally, some practical applications and the possibility of designing DC-DC converters for higher power levels are analyzed.

scholarly journals Improving Cyclability of Lithium Metal Anode via Constructing Atomic Interlamellar Ion Channel for Lithium Sulfur Battery

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Mao Yang ◽  
Nan Jue ◽  
Yuanfu Chen ◽  
Yong Wang
Keyword(s):  
Ion Channel ◽  
Coulombic Efficiency ◽  
Specific Capacity ◽  
Absorption Capacity ◽  
Lithium Metal ◽  
Metal Anode ◽  
Lithium Metal Anode ◽  
Li Ion ◽  
Sulfur Battery ◽  
Rapid Transfer

AbstractUniform migration of lithium (Li) ions between the separator and the lithium anode is critical for achieving good quality Li deposition, which is of much significance for lithium metal battery operation, especially for Li–sulfur (Li–S) batteries. Commercial separators such as polypropylene or polyethylene can be prepared by wet or dry processes, but they can indeed cause plentiful porosities, resulting in the uneven Li ion stripping/plating and finally the formation of Li dendrites. Thence, we constructed an atomic interlamellar ion channel by introducing the layered montmorillonite on the surface of the separator to guide Li ion flux and achieved stable Li deposition. The atomic interlamellar ion channel with a spacing of 1.4 nm showed strong absorption capacity for electrolytes and reserved capacity for Li ions, thus promoting rapid transfer of Li ions and resulting in even Li ion deposition at the anode. When assembled with the proposed separator, the Coulombic efficiency of Li||Cu batteries was 98.2% after 200 cycles and stable plating/stripping even after 800 h was achieved for the Li||Li symmetric batteries. Importantly, the proposed separator allows 140% specific capacity increase after 190 cycles as employing the Li–S batteries.

scholarly journals Wire-in-Wire TiO2/C Nanofibers Free-Standing Anodes for Li-Ion and K-Ion Batteries with Long Cycling Stability and High Capacity

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Die Su ◽  
Yi Pei ◽  
Li Liu ◽  
Zhixiao Liu ◽  
Junfang Liu ◽  
...  
Keyword(s):  
Critical Role ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
High Capacity ◽  
Cycling Stability ◽  
Free Standing ◽  
High Specific Capacity ◽  
Tetracarboxylic Dianhydride ◽  
Carbon Network

AbstractWearable and portable mobile phones play a critical role in the market, and one of the key technologies is the flexible electrode with high specific capacity and excellent mechanical flexibility. Herein, a wire-in-wire TiO2/C nanofibers (TiO2 ww/CN) film is synthesized via electrospinning with selenium as a structural inducer. The interconnected carbon network and unique wire-in-wire nanostructure cannot only improve electronic conductivity and induce effective charge transports, but also bring a superior mechanic flexibility. Ultimately, TiO2 ww/CN film shows outstanding electrochemical performance as free-standing electrodes in Li/K ion batteries. It shows a discharge capacity as high as 303 mAh g−1 at 5 A g−1 after 6000 cycles in Li half-cells, and the unique structure is well-reserved after long-term cycling. Moreover, even TiO2 has a large diffusion barrier of K+, TiO2 ww/CN film demonstrates excellent performance (259 mAh g−1 at 0.05 A g−1 after 1000 cycles) in K half-cells owing to extraordinary pseudocapacitive contribution. The Li/K full cells consisted of TiO2 ww/CN film anode and LiFePO4/Perylene-3,4,9,10-tetracarboxylic dianhydride cathode possess outstanding cycling stability and demonstrate practical application from lighting at least 19 LEDs. It is, therefore, expected that this material will find broad applications in portable and wearable Li/K-ion batteries.

scholarly journals Lamellar Polypyrene Based on Attapulgite–Sulfur Composite for Lithium–Sulfur Battery

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 483
Author(s):  
Jing Wang ◽  
Riwei Xu ◽  
Chengzhong Wang ◽  
Jinping Xiong
Keyword(s):  
Cathode Material ◽  
Current Density ◽  
High Current Density ◽  
Specific Capacity ◽  
Lithium Sulfur Batteries ◽  
Rate Test ◽  
Sulfur Battery ◽  
Lower Capacity ◽  
Lithium Sulfur

We report on the preparation and characterization of a novel lamellar polypyrrole using an attapulgite–sulfur composite as a hard template. Pretreated attapulgite was utilized as the carrier of elemental sulfur and the attapulgite–sulfur–polypyrrole (AT @400 °C–S–PPy) composite with 50 wt.% sulfur was obtained. The structure and morphology of the composite were characterized with infrared spectroscopy (IR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). An AT @400 °C–S–PPy composite was further utilized as the cathode material for lithium–sulfur batteries. The first discharge specific capacity of this kind of battery reached 1175 mAh/g at a 0.1 C current rate and remained at 518 mAh/g after 100 cycles with capacity retention close to 44%. In the rate test, compared with the polypyrrole–sulfur (PPy–S) cathode material, the AT @400 °C–S–PPy cathode material showed lower capacity at a high current density, but it showed higher capacity when the current came back to a low current density, which was attributed to the “recycling” of pores and channels of attapulgite. Therefore, the lamellar composite with special pore structure has great value in improving the performance of lithium–sulfur batteries.

Size-Dependent Elasticity of Silicon Nanowires

2009 ◽  
Vol 60-61 ◽  
pp. 315-319 ◽  
Author(s):  
W.W. Zhang ◽  
Qing An Huang ◽  
H. Yu ◽  
L.B. Lu
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Silicon Nanowires ◽  
First Principles ◽  
Si Nanowires ◽  
Size Dependent ◽  
Reconstructed Surfaces ◽  
Strain Relationship ◽  
Dynamics Simulations ◽  
Good Agreement

Molecular dynamics simulations are carried out to characterize the mechanical properties of [001] and [110] oriented silicon nanowires, with the thickness ranging from 1.05nm to 3.24 nm. The nanowires are taken to have ideal surfaces and (2×1) reconstructed surfaces, respectively. A series of simulations for square cross-section Si nanowires have been performed and Young’s modulus is calculated from energy–strain relationship. The results show that the elasticity of Si nanowires is strongly depended on size and surface reconstruction. Furthermore, the physical origin of above results is analyzed, consistent with the bond loss and saturation concept. The results obtained from the molecular dynamics simulations are in good agreement with the values of first-principles. The molecular dynamics simulations combine the accuracy and efficiency.

Potato Peel Based Carbon–Sulfur Composite as Cathode Materials for Lithium Sulfur Battery

2021 ◽  
Vol 21 (12) ◽  
pp. 6243-6247
Author(s):  
Arenst Andreas Arie ◽  
Shealyn Lenora ◽  
Hans Kristianto ◽  
Ratna Frida Susanti ◽  
Joong Kee Lee
Keyword(s):  
Cathode Materials ◽  
Porous Carbon ◽  
Chemical Activation ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Electrochemical Characteristics ◽  
Potato Peel ◽  
Lithium Sulfur Battery ◽  
Sulfur Battery ◽  
Lithium Sulfur

Lithium sulfur battery has become one of the promising rechargeable battery systems to replace the conventional lithium ion battery. Commonly, it uses carbon–sulfur composites as cathode materials. Biomass based carbons has an important role in enhancing its electrochemical characteristics due to the high conductivity and porous structures. Here, potato peel wastes have been utilized to prepare porous carbon lithium sulfur battery through hydrothermal carbonization followed by the chemical activation method using KOH. After sulfur loading, as prepared carbon–sulfur composite shows stable coulombic efficiencies of above 98% and a reversible specific capacity of 804 mAh g−1 after 100 cycles at current density of 100 mA g−1. These excellent electrochemical properties can be attributed to the unique structure of PPWC showing mesoporous structure with large specific surface areas. These results show the potential application of potato peel waste based porous carbon as electrode’s materials for lithium sulfur battery.

Bottom-up nanoscale patterning and selective deposition on silicon nanowires

2021 ◽  
Author(s):  
Amar Mohabir ◽  
Daniel Aziz ◽  
Amy Brummer ◽  
Kathleen Taylor ◽  
Eric Vogel ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
Electronic Devices ◽  
Spatial Relationship ◽  
Atomic Layer ◽  
Semiconductor Nanowires ◽  
Si Nanowires ◽  
Bottom Up ◽  
Nanoscale Patterning ◽  
Layer Deposition ◽  
Dopant Profile

Abstract We demonstrate a bottom-up process for programming the deposition of coaxial thin films aligned to the underlying dopant profile of semiconductor nanowires. Our process synergistically combines three distinct methods – vapor-liquid-solid (VLS) nanowire growth, selective coaxial lithography via etching of surfaces (SCALES), and area-selective atomic layer deposition (AS-ALD) – into a cohesive whole. Here, we study ZrO2 on Si nanowires as a model system. Si nanowires are first grown with an axially modulated n-Si/i-Si dopant profile. SCALES then yields coaxial poly(methyl methacrylate) (PMMA) masks on the n-Si regions. Subsequent AS-ALD of ZrO2 occurs on the exposed i-Si regions and not on those masked by PMMA. We show the spatial relationship between nanowire dopant profile, PMMA masks, and ZrO2 films, confirming the programmability of the process. The nanoscale resolution of our process coupled with the plethora of available AS-ALD chemistries promises a range of future opportunities to generate structurally complex nanoscale materials and electronic devices using entirely bottom-up methods.

Low-Energy Ion Irradiated Silicon Nanowires: Anomalous Plastic Deformation

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Chu Rainer Kwang-Hua
Keyword(s):  
Plastic Deformation ◽  
Silicon Nanowires ◽  
Room Temperature ◽  
Transition State Theory ◽  
State Theory ◽  
Si Nanowires ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Si Nanowire ◽  
Dependent Viscosity

We adopted the verified transition state theory, which originates from the quantum chemistry approach to explain the anomalous plastic flow or plastic deformation for Si nanowires irradiated with 100 keV (at room temperature regime) Ar+ ions as well as the observed amorphization along the Si nanowire (Johannes, et al. 2015, “Anomalous Plastic Deformation and Sputtering of Ion Irradiated Silicon Nanowires,” Nano Lett., 15, pp. 3800–3807). We shall illustrate some formulations which can help us calculate the temperature-dependent viscosity of flowing Si in nanodomains.

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