scholarly journals Continuous Composition Spread and Electrochemical Studies of Low Cobalt Content Li(Ni,Mn,Co)O2 Cathode Materials

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 366 ◽  
Author(s):  
JongSeok Jung ◽  
Haena Yim ◽  
Narendra Singh Parmar ◽  
Jae-Seung Lee ◽  
Ji-Won Choi
Keyword(s):  
Thin Film ◽  
Electrochemical Performance ◽  
Cathode Materials ◽  
Electrochemical Impedance ◽  
Cobalt Content ◽  
Electrochemical Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
X Ray Absorption

Many scientific efforts have been undertaken toward reducing the Co content in LiMn1/3Ni1/3Co1/3O2 cathode materials for thin-film batteries. In this study, we present cathodes with a wide range of Li(Ni, Mn, Co)O2 compositions to determine the material with the best electrochemical performance by changing the ratio of Ni to Mn at a fixed 0.1 at.% of Co by the continuous composition spread sputtering method. The cathode composition measurements by Rutherford backscattering spectroscopy show that the best electrochemical performance is obtained for a composition of Ni:Mn:Co = 19:71:10. The reasons for this improved electrochemical performance are further investigated by X-ray diffraction, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, and X-ray absorption near edge spectroscopy.

Electrochemical Performance Cr Doped Spinel LiMn2O4 Cathode for Lithium Ion Batteries

2014 ◽  
Vol 636 ◽  
pp. 49-53
Author(s):  
Si Qi Wen ◽  
Liang Chao Gao ◽  
Jia Li Wang ◽  
Lei Zhang ◽  
Zhi Cheng Yang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Cycle Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Discharge Test

To improve the cycle performance of spinel LiMn2O4as the cathode of 4 V class lithium ion batteries, spinel were successfully prepared using the sol-gel method. The dependence of the physicochemical properties of the spinel LiCrxMn2-xO4(x=0,0.05,0.1,0.2,0.3,0.4) powders powder has been extensively investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), charge-discharge test and electrochemical impedance spectroscopy (EIS). The results show that as Mn is replaced by Cr, the initial capacity decreases, but the cycling performance improves due to stabilization of spinel structure. Of all, the LiCr0.2Mn1.8O4has best electrochemical performance, 107.6 mAhg-1discharge capacity, 96.1% of the retention after 50 cycles.

Evaluation of Pulsed Laser Deposited Li4Ti5O12 Thin Film Anodes by CV and EIS

2013 ◽  
Vol 743-744 ◽  
pp. 13-19 ◽  
Author(s):  
Jian Qiu Deng ◽  
Zhou Guang Lu ◽  
Chi Yuen Chung ◽  
Zhong Min Wang ◽  
Huai Ying Zhou
Keyword(s):  
Thin Film ◽  
Electrochemical Impedance ◽  
Discharge Rate ◽  
Pulsed Laser ◽  
Environmental Scanning Electron Microscopy ◽  
Cycling Performance ◽  
Laser Deposition ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
X Ray

Li4Ti5O12thin film anodes were prepared successfully using pulsed laser deposition technique. The thin films were characterized by X-ray diffraction and environmental scanning electron microscopy. The effects of thickness and scan rate on the electrochemical properties of Li4Ti5O12thin film electrodes were discussed in detail. The thin film anodes deliver favorable capacity and excellent cycling performance. The discharge capacity maintains at 141 mAhg-1after 20 cycles at 1C charge-discharge rate for the thin film anodes deposited for 20 minutes. The charge-transfer resistances were also investigated by electrochemical impedance spectroscopy.

Controlled Synthesis of Nanostructured Nickel Oxide Thin Film for Supercapacitor Application

2018 ◽  
Vol 24 (8) ◽  
pp. 5587-5592
Author(s):  
S. C Bhise ◽  
D. V Awale ◽  
M. M Vadiyar ◽  
S. K Patil ◽  
B. N Kokare ◽  
...  
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Oxide Thin Film ◽  
Storage Device ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Supercapacitor Application ◽  
Nio Thin Film

In the present work we report the controlled synthesis of NiO thin film with nano-leaves like morphology using reflux method. The synthesized NiO electrode is used as working electrode for supercapacitor application. The deposited NiO thin film was characterized using thermogravimetric (TGA) analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The supercapacitor behaviour of NiO was investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy using 3 M KOH electrolyte. The electrochemical results show specific capacitance of 513 F g−1 at 10 mV s−1 scan rate, power density (10.44 kW kg−1), energy density (14 Wh kg−1) and 85% capacitance retention over 5000 cycles. These remarkable results indicate the importance of the NiO nano-leaves electrode in energy storage device.

Preparation and properties of solid electrolyte CaxBi1.7−xW0.3O3.45−0.5x electrolyte material by sol–gel combution method

2019 ◽  
Vol 12 (05) ◽  
pp. 1951001
Author(s):  
Jie Yang ◽  
Changan Tian ◽  
Yu Wang ◽  
Junjie Meng ◽  
Dongdong Ji ◽  
...  
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Combustion Method ◽  
Solid Oxide ◽  
Electrochemical Studies ◽  
Oxide Fuel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Differential Thermogravimetric Analysis

CaxBi[Formula: see text]W[Formula: see text]O[Formula: see text] (CBW) ([Formula: see text], 0.05, 0.10, 0.15, 0.20, 0.30) electrolyte material were synthesized by sol–gel self-combustion method. The samples were characterized by thermogravimetric-differential thermogravimetric analysis(TG-DSC), X-ray diffraction, scanning electron microscopy (SEM), porosity and electrochemical impedance spectroscopy (EIS). The results show the powders CaxBi[Formula: see text]W[Formula: see text]O[Formula: see text] (CBW) with fluorite crystal structure can be obtained after the precursor was calcined at 760∘C. When sintered at 780∘C for 2[Formula: see text]h, the compact ceramic sintered with relative density higher than 97% can be obtained. The electrochemical studies showed that CaxBi[Formula: see text]W[Formula: see text]O[Formula: see text] (CBW) have high ionic conductivity after 780∘C sintering. The sample Ca[Formula: see text]Bi[Formula: see text]W[Formula: see text]O[Formula: see text] exhibits a conductivity of 0.07978 S[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] at 750∘C, and the activation energy is 0.845[Formula: see text]eV, which is expected to be applied to the electrolyte materials for intermediate temperature solid oxide fuel cells (SOFC).

scholarly journals Hydrothermally Synthesized Nanostructured LiMnxFe1-xPO4 (x = 0-0.3) Cathode Materials With Enhanced Properties for Lithium-Ion Batteries

2021 ◽  
Author(s):  
Dung V. Trinh ◽  
Mai T. T. Nguyen ◽  
Hue T. M. Dang ◽  
Dung T. Dang ◽  
Hang T. T. Le ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Slight Reduction ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
X Ray ◽  
Capacity Loss ◽  
Galvanostatic Intermittent Titration Technique ◽  
Mn Doped

Abstract Nanostructured cathode materials based on Mn-doped olivine LiMnxFe1-xPO4 (x = 0, 0.1, 0.2, and 0.3) were successfully synthesized via a hydrothermal route. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (SEM), and Raman spectroscopy indicated that the synthesized samples possessed a sphere-like nanostructure and a relatively homogeneous size distribution in the range of 100 - 200 nm. Electrochemical experiments and analysis showed that the Mn doping increased the redox potential and boosted the capacity. While the undoped olivine (LiFePO4) had a capacity of 169 mAh g-1 with a slight reduction (10%) in the initial capacity after 50 cycles (150 mAh g-1), the Mn-doped olivine samples (LiMnxFe1-xPO4) demonstrated reliable cycling tests with negligible capacity loss, reaching 151, 147, and 157 mAh g-1 for x = 0.1, 0.2, and 0.3, respectively. The results from electrochemical impedance spectroscopy (EIS) accompanied by the galvanostatic intermittent titration technique (GITT) confirmed that the Mn substitution for Fe promoted the charge transfer process and hence the rapid Li transport. These findings indicate that the LiMnxFe1-xPO4 nanostructures are promising cathode materials for lithium ion battery applications.

Electrochemical Studies and Images Performance of La2O3/TiO2 for Energy Storage

MRS Advances ◽  
2016 ◽  
Vol 1 (6) ◽  
pp. 395-402
Author(s):  
C.G. Nava-Dino ◽  
N.L. Mendez-Mariscal ◽  
G. Llerar-Meza ◽  
R.A. Acosta-Chavéz ◽  
M.E. Lopéz-Ochoa ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Counter Electrode ◽  
Weight Ratio ◽  
Reference Electrode ◽  
Electrochemical Studies ◽  
X Ray Diffraction ◽  
Storage Material ◽  
X Ray ◽  
Ball Milling Technique ◽  
Experimental Runs

ABSTRACTPowders of La2O3 were mixed with mechanical ball-milling technique (MA) adding TiO2, to improve the electrochemical performance as a storage material. Microstructures, morphologies and electrochemical results were investigated using TEM, X-ray diffraction (XRD), Cyclic Voltammetry and Potentiodynamic studies. Results showed that, the samples with TiO2 content affected the capacity of response. The alloys exhibit a superior capacity and stability adding TiO2. The milling ball to powder weight ratio was kept 5 to 1 for all experimental runs. Milling intervals were 0, 2 and 4 hrs; using alternate cycles of 30 minutes milling and 30 min resting. The nanostructure TiO2 powder, improves the samples to design a better electrode. TiO2 has significant influence on electrochemical performance of electrodes. Electrochemical experiments were performed on ACM Instruments Gill AC and a typical three electrode setup was constructed to measure the electrochemical properties of the working electrode. Here, platinum was used as the counter electrode and calomel was used as the reference electrode. Structures of the samples were analyzed by digital image tools.

scholarly journals Influence of particle size and fluorination ratio of CF x precursor compounds on the electrochemical performance of C–FeF2 nanocomposites for reversible lithium storage

2013 ◽  
Vol 4 ◽  
pp. 705-713 ◽  
Author(s):  
Ben Breitung ◽  
M Anji Reddy ◽  
Venkata Sai Kiran Chakravadhanula ◽  
Michael Engel ◽  
Christian Kübel ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrochemical Performance ◽  
Cathode Materials ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Lithium Storage ◽  
One Pot ◽  
Electrically Conductive ◽  
X Ray ◽  
Electron Energy Loss

Systematical studies of the electrochemical performance of CF x -derived carbon–FeF2 nanocomposites for reversible lithium storage are presented. The conversion cathode materials were synthesized by a simple one-pot synthesis, which enables a reactive intercalation of nanoscale Fe particles in a CF x matrix, and the reaction of these components to an electrically conductive C–FeF2 compound. The pretreatment and the structure of the utilized CF x precursors play a crucial role in the synthesis and influence the electrochemical behavior of the conversion cathode material. The particle size of the CF x precursor particles was varied by ball milling as well as by choosing different C/F ratios. The investigations led to optimized C–FeF2 conversion cathode materials that showed specific capacities of 436 mAh/g at 40 °C after 25 cycles. The composites were characterized by Raman spectroscopy, X-Ray diffraction measurements, electron energy loss spectroscopy and TEM measurements. The electrochemical performances of the materials were tested by galvanostatic measurements.

Carbon Nanotubes/MnO2 Composite Fabricated via Laser Welding and Electrodeposition as Flexible Electrode for Supercapacitors

NANO ◽  
2019 ◽  
Vol 14 (06) ◽  
pp. 1950074 ◽  
Author(s):  
Mingping He ◽  
Jianguang Li ◽  
Wanli Xu ◽  
Zhenqiang Dong ◽  
Yuechao Wu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Performance ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Easy Access ◽  
Cyclic Voltammogram ◽  
X Ray Diffraction ◽  
Porous Network ◽  
Flexible Electrode ◽  
X Ray

Carbon nanotubes (CNTs) were welded on the surface of thermoplastic polypropylene (PP) substrate by laser irradiation and then manganese dioxide (MnO2) was deposited on the surface of CNTs by electrochemical method to prepare CNTs/MnO2 flexible electrodes (L-CM). The microstructure and morphology of CNTs/MnO2 composites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results showed that CNTs were welded on the surface of the substrate, adhering to each other to form a porous network structure. In addition, there were distinct small protrusions on the surface of CNTs, indicating that MnO2 had been successfully deposited on the surface of CNTs. Cyclic voltammogram (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques were employed to investigate the electrochemical performance of the composites. Compared with CNTs/MnO2 composite prepared via compaction (denoted as C-CM), L-CM composite prepared under the laser power of 0.75[Formula: see text]W (denoted as L-CM75) showed a larger capacitance of 214.6[Formula: see text]F[Formula: see text]g[Formula: see text] at the current density of 0.5[Formula: see text]A[Formula: see text]g[Formula: see text] and displayed excellent bendability, demonstrating capacitance retention of approximately 89.6% after 1000 bending cycles. The excellent performance of L-CM75 may be attributed to the fact that the CNTs welded on the substrate have formed an effective conductive network whose porous structure can facilitate easy access of electrolytes to the electrode, which results in enhancement of the electrochemical performance of L-CM75.

Electrochemical Performance of Carbon Nanofibers/Cobalt Ferrite (CNF/CoFe2O4) Composites Synthesized by Two Approaches

2021 ◽  
Vol 18 (4) ◽  
Author(s):  
Rounak R. Atram ◽  
Nutan V. Mangate ◽  
Ramdas G. Atram ◽  
Subhash B. Kondawar
Keyword(s):  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Carbon Nanofibers ◽  
Cobalt Ferrite ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Excellent Electrochemical Performance ◽  
Hydrothermal Methods

Abstract In this paper, we report the fabrication of activated carbon nanofibers/cobalt ferrite (CNF/CoFe2O4) composites by electrospinning and hydrothermal methods for comparative study of electrochemical properties. The structural, morphological, and compositional analyses of the synthesized composites were examined using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy. CNF/CoFe2O4 electrodes were investigated for electrochemical behavior using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge–discharge (GCD). The results showed that hydrothermally synthesized CNF/CoFe2O4 composite exhibited the specific capacitance 188.36 F/g, whereas electrospun CNF/CoFe2O4 composite resulted the specific capacitance 106.59 F/g at lowest current density 0.5 A/g. 80% capacitance retention of CNF/CoFe2O4 prepared by hydrothermal as compared with 60% capacitance retention of CNF/CoFe2O4 prepared by electrospinning. These results concluded that CNF/CoFe2O4 electrode obtained by hydrothermal exhibited comparatively excellent electrochemical performance and found its suitability as electrodes for supercapacitors.

Electrochemical Performance of Spherical Li3V2(PO4)3/C Synthesized by Spray Drying Method

2017 ◽  
Vol 727 ◽  
pp. 738-743 ◽  
Author(s):  
Zong Lin Zuo ◽  
Jin Wang ◽  
Jian Qiu Deng ◽  
Qing Rong Yao ◽  
Zhong Min Wang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Spray Drying ◽  
Cathode Materials ◽  
Lithium Ion ◽  
Drying Method ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Voltage Range ◽  
X Ray ◽  
Discharge Capacities

Spherical Li3V2(PO4)3/C cathode materials have been successfully synthesized by a spray drying method. The structure and morphology of the cathode materials are characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric (TG) analysis. The results show that synthesized monoclinic Li3V2(PO4)3 with high purities exhibits spherical morphology, in favor of enhancing the capacities and cycling stability of Li3V2(PO4)3/C cathode materials for lithium-ion battery. The Li3V2(PO4)3/C cathode materials sintered at 750 °C present best electrochemical performance among all the samples. It exhibits high initial discharge capacities of 99.2 mAhg-1 and capacity retention of 93.6% after 200 cycles at a rate of 1C within a voltage range of 3.0–4.3 V.

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