scholarly journals Performance of the Chemical and Electrochemical Composites of PPy/CNT as Electrodes in Type I Supercapacitors

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
S. C. Canobre ◽  
F. F. S. Xavier ◽  
W. S. Fagundes ◽  
A. C. de Freitas ◽  
F. A. Amaral
Keyword(s):  
Coulombic Efficiency ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Promising Material ◽  
Cyclic Voltammograms ◽  
Type I ◽  
Counter Electrodes ◽  
Light Emitting Devices ◽  
High Electronic Conductivity ◽  
P Type

Polypyrrole (PPy) is one of the most studied conducting polymers and a very promising material for various applications such as lithium-ion secondary batteries, light-emitting devices, capacitors, and supercapacitors, owing to its many advantages, including good processability, easy handling, and high electronic conductivity. In this work, PPy films were chemically and electrochemically synthesized, both in and around carbon nanotubes (CNTs). The cyclic voltammograms of the device, composed of the electrochemically synthesized PPy/CNT composites as working and counter electrodes (Type I supercapacitor with p-type doping), showed a predominantly capacitive profile with low impedance values and good electrochemical stability, with the anodic charge remaining almost constant (11.38 mC), a specific capacitance value of 530 F g−1after 50 charge and discharge cycles, and a coulombic efficiency of 99.2%. The electrochemically synthesized PPy/CNT composite exhibited better electrochemical properties compared to those obtained for the chemically synthesized composite. Thus, the electrochemically synthesized PPy/CNT composite is a promising material to be used as electrodes in Type I supercapacitors.

scholarly journals Surface nitridation of Li4Ti5O12 by thermal decomposition of urea to improve quick charging capability of lithium ion batteries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jihyun Jang ◽  
Tae Hun Kim ◽  
Ji Heon Ryu
Keyword(s):  
Lithium Ion Batteries ◽  
Coulombic Efficiency ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
Negative Electrode ◽  
Lithium Ion ◽  
High Rate ◽  
High Electronic Conductivity ◽  
Negative Electrode Material ◽  
Initial Coulombic Efficiency

AbstractAs the application of lithium-ion batteries in electric vehicles increases, the demand for improved charging characteristics of batteries is also increasing. Lithium titanium oxide (Li4Ti5O12, LTO) is a negative electrode material with high rate characteristics, but further improvement in rate characteristics is needed for achieving the quick-charging performance required by electric vehicle markets. In this study, the surface of LTO was coated with a titanium nitride (TiN) layer using urea and an autogenic reactor, and electrochemical performance was improved (initial Coulombic efficiency and the rate capability were improved from 95.6 to 4.4% for pristine LTO to 98.5% and 53.3% for urea-assisted TiN-coated LTO, respectively. We developed a process for commercial production of surface coatings using eco-friendly material to further enhance the charging performance of LTO owing to high electronic conductivity of TiN.

PROPERTIES OF ALL-SOLID-STATE LITHIUM-ION RECHARGEABLE BATTERIES DEPOSITED BY RF MAGNETRON SPUTTERING

2013 ◽  
Vol 27 (22) ◽  
pp. 1350156 ◽  
Author(s):  
R. J. ZHU ◽  
Y. REN ◽  
L. Q. GENG ◽  
T. CHEN ◽  
L. X. LI ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solid State ◽  
Magnetron Sputtering ◽  
Coulombic Efficiency ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Rf Magnetron Sputtering ◽  
Rechargeable Batteries ◽  
Voltage Range

Amorphous V 2 O 5, LiPON and Li 2 Mn 2 O 4 thin films were fabricated by RF magnetron sputtering methods and the morphology of thin films were characterized by scanning electron microscopy. Then with these three materials deposited as the anode, solid electrolyte, cathode, and vanadium as current collector, a rocking-chair type of all-solid-state thin-film-type Lithium-ion rechargeable battery was prepared by using the same sputtering parameters on stainless steel substrates. Electrochemical studies show that the thin film battery has a good charge–discharge characteristic in the voltage range of 0.3–3.5 V, and after 30 cycles the cell performance turned to become stabilized with the charge capacity of 9 μAh/cm2, and capacity loss of single-cycle of about 0.2%. At the same time, due to electronic conductivity of the electrolyte film, self-discharge may exist, resulting in approximately 96.6% Coulombic efficiency.

NANOSTRUCTURED SnO2/C COMPOSITE ANODES IN LITHIUM-ION BATTERIES

2003 ◽  
Vol 02 (04n05) ◽  
pp. 299-306 ◽  
Author(s):  
CHIEN-TE HSIEH ◽  
JIN-MING CHEN ◽  
HSIU-WEN HUANG
Keyword(s):  
Lithium Ion Batteries ◽  
Discharge Capacity ◽  
Coulombic Efficiency ◽  
Sol Gel ◽  
Lithium Ion ◽  
Surface Characteristics ◽  
Carbon Surface ◽  
Cyclic Voltammograms ◽  
Composite Anodes ◽  
Sol Gel Synthesis

Nanostructured SnO 2/ C composites used as anode materials were prepared by sol–gel synthesis to explore electrochemical properties in lithium-ion batteries. Surface characteristics of the SnO 2/ C nanocomposite were analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that nanocrystalline SnO 2/ C with a grain size of 20–50 nm was uniformly dispersed on the carbon surface. After nanocrytalline SnO 2 coated onto carbon, the discharge capacity showed an increase up to 23%, i.e., from 300 to 370 mAh/g at a current density of 0.6 mA/cm2. The nanocomposite anode can achieve a fairly stable discharge capacity and excellent Coulombic efficiency (>99.5%) over 50 cycles. Cyclic voltammograms indicated that the improvements on capacity and cycleability were due to reversible alloying of nanosized Sn and Li on carbon surface.

Nanoporous MnO2 Nanoflakes Modified Carbon Cloth Material for Efficient Removal of Heavy Metal Ions in Water by Capacitive Deionization

2018 ◽  
Vol MA2018-01 (32) ◽  
pp. 1973-1973
Author(s):  
Ying Wang ◽  
Daniel J Blackwood
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Electronic Conductivity ◽  
Porous Electrodes ◽  
Carbon Cloth ◽  
List Type ◽  
Capacitive Deionization ◽  
Counter Electrodes ◽  
High Electronic Conductivity

Increasing demand for the limited resource of fresh water for the large urban populations and development of agriculture and industry draws public concern. Removal of heavy metals such as lead, cadmium, chromium and mercury is crucial in environmental improvement of water and industrial wastewater treatment. Great efforts have been made through chemical precipitation, adsorption, ion exchange, filtration and electrochemical treatment. However, a large volume of sludge residue, expensive and complex matrix materials and low efficiency are still problems that need to be improved. Capacitive deionization (CDI) is a promising energy-efficient technology for water desalination, which is easy to handle and environmentally friendly producing no secondary contaminants through the water purifying process [1]. In order to effectively remove ions, the porous electrodes with large surface area, good chemical stability, high electronic conductivity, and hydrophility are key factors in the selection of CDI materials. Highly porous carbon materials represent the typical electrodes to store the ions through surface ion adsorption/desorption, which is generally categorized as electrochemical double layer. By contrast, pseudocapacitors that consist of conducting polymers and transition metals, store more charge through redox reactions. Among the alternative candidates, the natural abundant and environmental benign MnO2 is of particular interest for research, due to its high theoretical specific capacitance and the ability to be use in mild aqueous electrolytes which expand its practical application [2-3]. MnO2 can be fabricated easily and its morphology can be controlled during simple hydrothermal growth processes. Direct growth on carbon cloth, which is an excellent flexible and conductive substrate, could enhance the regeneration and reuse property of MnO2 as an ideal CDI electrode. Porous MnO2@cabon cloth composites were prepared via a facile hydrothermal method (Figure a). The BET result showed that the average pore width is 18.2 nm. To investigate the CDI property of removing the heavy metal ions, one piece of MnO2@CC and one piece of activated carbon@graphite paper were assembled as working and counter electrodes respectively. This work confirmed the potential of using MnO2@CC as a good CDI electrode material for removal of heavy metal ions from water (Figure b). References S. Porada, R. Zhao, A. Wal, V. Presser, and P. M. Biesheuvel, Prog. Mater. Sci., 58, 1388 (2013). W. Wei, X. Cui, W. Chen, and D. G. Ivey, Chem. Soc. Rev., 40, 1697 (2011). J. Wang, F. Kang, and B. Wei, Prog. Mater. Sci., 74, 51 (2015). Figure 1

scholarly journals Nanocomposite of Si/C Anode Material Prepared by Hybrid Process of High-Energy Mechanical Milling and Carbonization for Li-Ion Secondary Batteries

2018 ◽  
Vol 8 (11) ◽  
pp. 2140 ◽  
Author(s):  
Reddyprakash Maddipatla ◽  
Chadrasekhar Loka ◽  
Woo Choi ◽  
Kee-Sun Lee
Keyword(s):  
Electron Microscopy ◽  
Anode Material ◽  
Mechanical Milling ◽  
Coulombic Efficiency ◽  
Electronic Conductivity ◽  
High Capacity ◽  
Lithium Ion ◽  
High Energy ◽  
Particle Size Reduction ◽  
Milled Powders

Si/C nanocomposite was successfully prepared by a scalable approach through high-energy mechanical milling and carbonization process. The crystalline structure of the milled powders was studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Morphology of the milled powders was investigated by Field-emission scanning electron microscopy (FE-SEM). The effects of milling time on crystalline size, crystal structure and microstructure, and the electrochemical properties of the nanocomposite powders were studied. The nanocomposite showed high reversible capacity of ~1658 mAh/g with an initial cycle coulombic efficiency of ~77.5%. The significant improvement in cyclability and the discharge capacity was mainly ascribed to the silicon particle size reduction and carbon layer formation over silicon for good electronic conductivity. As the prepared nanocomposite Si/C electrode exhibits remarkable electrochemical performance, it is potentially applied as a high capacity anode material in the lithium-ion secondary batteries.

High-Rate Charge/Discharge Properties of Li Ion Secondary Battery Using V2O5/Carbon Composite Electrodes with Carbon Fiber

2006 ◽  
Vol 301 ◽  
pp. 159-162
Author(s):  
Akira Kuwahara ◽  
Shinya Suzuki ◽  
Masaru Miyayama
Keyword(s):  
Carbon Fiber ◽  
Current Density ◽  
High Current Density ◽  
Fiber Composite ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
High Rate ◽  
Composite Electrodes ◽  
High Electronic Conductivity ◽  
Charge Discharge

The charge/discharge properties of V2O5/carbon composites with controlled microstructures were investigated to achieve a high-rate lithium electrode performance. Composite electrodes were synthesized by mixing a V2O5 sol, carbon and a surfactant, followed by drying. V2O5/AB (acetylene black) and V2O5/VGCF (vapor-grown carbon fiber) composite electrodes showed high-rate charge/discharge properties only when they had very high carbon contents. V2O5/ (AB and VGCF) composite electrodes with controlled microstructures exhibited a discharge capacity of 245 mA·h·g-1 at a high current density of 40 A·g-1, which was approximately 70% of that at a low current density of 100 mA·g-1. The improvement in the high-rate charge/discharge properties was attributed to the short lithium ion diffusion distance, large reaction area and high electronic conductivity of those composite electrodes.

scholarly journals A Flexible Electron-blocking Interfacial Shield for Dendrite-free Solid Lithium Metal Batteries

2020 ◽  
Author(s):  
Hanyu Huo ◽  
Jian Gao ◽  
Ning Zhao ◽  
Dongxing Zhang ◽  
Nathaniel Holmes ◽  
...  
Keyword(s):  
Solid State ◽  
Density Functional ◽  
Rational Design ◽  
Electron Tunneling ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Density Functional Theory Calculations ◽  
High Electron ◽  
High Electronic Conductivity ◽  
Battery Technology

Abstract Solid-state batteries (SSBs) are considered to be the next-generation lithium-ion battery technology due to their enhanced energy density and safety. However, the high electronic conductivity of solid-state electrolytes (SSEs) leads to Li dendrite nucleation and proliferation. Uneven electric-field distribution resulting from poor interfacial contact can further promote dendritic deposition and lead to rapid short circuiting of SSBs. Herein, a flexible electron-blocking interfacial shield (EBS) is proposed to protect garnet electrolytes from the electronic degradation. The EBS formed by an in-situ substitution reaction can not only increase lithiophilicity but also stabilize the Li volume change, maintaining the integrity of the interface during repeated cycling. Density functional theory calculations show a high electron-tunneling energy barrier from Li metal to the EBS, indicating an excellent capacity for electron-blocking. EBS protected cells exhibit an improved critical current density of 1.2 mA cm-2 and stable cycling for over 400 h at 1 mA cm-2 (1 mAh cm-2) at room temperature. These results demonstrate an effective strategy for the suppression of Li dendrites and present fresh insight into the rational design of the SSE and Li metal interface.

scholarly journals Lithia-Based Nanocomposites Activated by Li2RuO3 for New Cathode Materials Rooted in the Oxygen Redox Reaction

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Byeong Gwan Lee ◽  
Yong Joon Park
Keyword(s):  
Lithium Ion Batteries ◽  
Cathode Materials ◽  
Redox Reaction ◽  
Electronic Conductivity ◽  
High Capacity ◽  
Lithium Ion ◽  
Xps Analysis ◽  
Cyclic Performance ◽  
Capacity Limit ◽  
High Electronic Conductivity

AbstractLithia-based materials are promising cathodes based on an anionic (oxygen) redox reaction for lithium ion batteries due to their high capacity and stable cyclic performance. In this study, the properties of a lithia-based cathode activated by Li2RuO3 were characterized. Ru-based oxides are expected to act as good catalysts because they can play a role in stabilizing the anion redox reaction. Their high electronic conductivity is also attractive because it can compensate for the low conductivity of lithia. The lithia/Li2RuO3 nanocomposites show stable cyclic performance until a capacity limit of 500 mAh g−1 is reached, which is below the theoretical capacity (897 mAh g−1) but superior to other lithia-based cathodes. In the XPS analysis, while the Ru 3d peaks in the spectra barely changed, peroxo-like (O2)n− species reversibly formed and dissociated during cycling. This clearly confirms that the capacity of the lithia/Li2RuO3 nanocomposites can mostly be attributed to the anionic (oxygen) redox reaction.

Synthesis and Electrochemical Properties of Y-Doped SnO2/C Composite Materials for Lithium-Ion Battery

2011 ◽  
Vol 197-198 ◽  
pp. 1157-1162 ◽  
Author(s):  
Sheng Kui Zhong ◽  
You Wang ◽  
Chang Jiu Liu ◽  
Yan Wei Li ◽  
Yan Hong Li
Keyword(s):  
Particle Size ◽  
Electrochemical Impedance ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Precipitation Method ◽  
Cyclic Voltammograms ◽  
Sem Images ◽  
Electrochemical Impedance Spectra ◽  
Transfer Resistance

The layered Y-doped SnO2/C anode materials were prepared by a co-precipitation method. The physical properties of the Y-doped SnO2/C were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical measurements. XRD studies showed that the Y-doped SnO2/C has the same layered structure as the undoped SnO2/C. The SEM images exhibited that the particle size of Y-doped SnO2/C is smaller than that of the undoped SnO2/C and the smallest particle size is only about 1µm. The Y-doped SnO2/C samples were investigated on the Lithium extraction/insertion performances by charge/discharge, cyclic voltammograms (CV), and electrochemical impedance spectra (EIS). The results showed that the optimal doping content of Y was that x=0.07 and 2% content of carbon nanotubes samples to achieve high discharge capacity and good cyclic stability. The electrode reaction reversibility and electronic conductivity were enhanced, and the charge transfer resistance was decreased through Y-doping.

scholarly journals Synthesis and Characterization of Stable and Binder-Free Electrodes of TiO2Nanofibers for Li-Ion Batteries

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Phontip Tammawat ◽  
Nonglak Meethong
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Impedance ◽  
Coulombic Efficiency ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Electrospun Nanofibers ◽  
Average Diameter ◽  
Reversible Capacity ◽  
Electrospinning Technique ◽  
Binder Free

An electrospinning technique was used to fabricate TiO2nanofibers for use as binder-free electrodes for lithium-ion batteries. The as-electrospun nanofibers were calcined at 400–1,000°C and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). SEM and TEM images showed that the fibers have an average diameter of ~100 nm and are composed of nanocrystallites and grains, which grow in size as the calcination temperature increases. The electrochemical properties of the nanofibers were evaluated using galvanostatic cycling and electrochemical impedance spectroscopy. The TiO2nanofibers calcined at 400°C showed higher electronic conductivity, higher discharge capacity, and better cycling performance than the nanofibers calcined at 600, 800, and 1,000°C. The TiO2nanofibers calcined at 400°C delivered an initial reversible capacity of 325 mAh·g−1approaching their theoretical value at 0.1 C rate and over 175 mAh·g−1at 0.3 C rate with limited capacity fading and Coulombic efficiency between 96 and 100%.

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