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.

Facile synthesis of nickel-based metal organic framework [Ni3(HCOO)6] by microwave method and application for supercapacitor

2018 ◽  
Vol 11 (02) ◽  
pp. 1850030 ◽  
Author(s):  
Jujie Luo ◽  
Xing Yang ◽  
Shumin Wang ◽  
Yuhong Bi ◽  
Amit Nautiyal ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Metal Organic Framework ◽  
Microwave Method ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
Facile Synthesis ◽  
X Ray ◽  
Irradiation Power ◽  
Metal Organic ◽  
Organic Framework

The metal organic framework (MOF) [Ni3(HCOO)6] was synthesized via the simple and fast microwave method, and the effect of irradiation power on crystallinity of synthesized Ni-based MOF was studied. The samples were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The synthesized Ni-based MOF was electrochemically characterized by using galvanostatic charge–discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. The synthesized MOF showed the highest specific capacitance of 1196.2[Formula: see text]F/g at 1[Formula: see text]A/g with excellent cyclability (86.04% capacitance retention after 2,000 cycles), thereby demonstrating its potential application in supercapacitors.

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.

Influence of Nanosized α-Ni(OH)2 Addition on the Electrochemical Performance of β-Ni(OH)2 Electrode

2007 ◽  
Vol 121-123 ◽  
pp. 1265-1268 ◽  
Author(s):  
T.A. Han ◽  
J.P. Tu ◽  
Jian Bo Wu ◽  
Y.F. Yuan ◽  
Y. Li
Keyword(s):  
Electrochemical Performance ◽  
Active Material ◽  
Spherical Shape ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Co Precipitation ◽  
Charge Discharge ◽  
Scanning Electron

Al-substituted α-Ni(OH)2 was synthesized by a chemical co-precipitation. The as-prepared α-Ni(OH)2 particles were characterized by the means of X-ray diffraction (XRD) and scanning electron microscope (SEM). The obtained α-Ni(OH)2 particles were well crystallized, spherical shape with the particle sizes of 20-35 nm. The electrochemical performance of β-Ni(OH)2 electrode with addition of nanosized α-Ni(OH)2 was investigated by galvanostatic charge-discharge tests. The nanosized α-Ni(OH)2 as additive in the commercial microsized spherical β-Ni(OH)2 electrode improved the discharge capability. As compared to commercial β-Ni(OH)2 electrode, the electrode with nanosized α-Ni(OH)2 exhibited excellent better charge-discharge cycling stability. It may be a promising positive active material for alkaline secondary batteries.

Preparation of Nickel and Manganese Dioxide by Co-Precipitation and its Electrochemical Capacitive Properties

2015 ◽  
Vol 814 ◽  
pp. 86-90
Author(s):  
Qian Qian Li ◽  
Run Hua Fan ◽  
Yu Jun Bai ◽  
Chuan Bing Cheng ◽  
Gui Fang Liu ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Manganese Oxides ◽  
Electrochemical Impedance ◽  
Spherical Particles ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Capacitive Properties ◽  
Co Precipitation ◽  
Redox Capacitance

The precursor nickel and manganese carbonates were synthesized by co-precipitation with sodium carbonate as precipitant, and then nickel and manganese oxides were gained after calcination. The phase and morphology of the synthesized product were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the electrochemical characterization was performed using cyclic voltammetry (CV), galvanostatic charge–discharge tests (GCD) and electrochemical impedance spectroscopy (EIS) in a 6mol/L KOH aqueous solution electrolyte. The result showed that the products were the mixture of nickel and manganese oxides and solid solution. nanoparticles and spherical particles were gained by controlling the molar ratio of nickel and manganese. All of the samples exhibited typical Faradic redox capacitance. The specific capacitance was different with the change of nickel and manganese molar ratio. The specific capacitance (Cs) reached 130F/g at 1A/g when the ratio was 2:1.

Surface modification and electrochemical properties of activated carbons for supercapacitor electrodes

2015 ◽  
Vol 29 (Supplement 1) ◽  
pp. 1550254 ◽  
Author(s):  
Dan Yang ◽  
Wenmei Qiu ◽  
Jingcai Xu ◽  
Yanbing Han ◽  
Hongxiao Jin ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Activated Carbons ◽  
Chemical Properties ◽  
Bet Surface Area ◽  
Surface Chemical ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Charge Discharge

Modifications with different acids (HNO3, H2SO4, HCl and HF, respectively) were introduced to treat the activated carbons (ACs) surface. The microstructures and surface chemical properties were discussed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), ASAP, Raman spectra and Fourier transform infrared (FTIR) spectra. The ACs electrode-based supercapacitors were assembled with 6 mol ⋅ L[Formula: see text] KOH electrolyte. The electrochemical properties were studied by galvanostatic charge–discharge and cyclic voltammetry. The results indicated that although the BET surface area of modified ACs decreased, the functional groups were introduced and the ash contents were reduced on the surface of ACs, receiving larger specific capacitance to initial AC. The specific capacitance of ACs modified with HCl, H2SO4, HF and HNO3 increased by 31.4%, 23%, 21% and 11.6%, respectively.

ELECTRODEPOSITION OF POLYPYRROLE/MnO2 NANOCOMPOSITE ON GRAPHITE FELT AS FREE-STANDING ELECTRODE FOR SUPERCAPACITORS

NANO ◽  
2013 ◽  
Vol 08 (02) ◽  
pp. 1350020 ◽  
Author(s):  
MINGPING HE ◽  
YUYING ZHENG ◽  
QIFENG DU
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Manganese Dioxide ◽  
Specific Capacitance ◽  
Electrochemical Impedance ◽  
Easy Access ◽  
Cyclic Voltammogram ◽  
Free Standing ◽  
X Ray ◽  
Graphite Felt

Polypyrrole/manganese dioxide nanocomposite was deposited on graphite felt (GF) via electrodeposition to fabricate polypyrrole/manganese dioxide/graphite felt (PYMG), which can be used as novel free-standing electrode for supercapacitors. The microstructure and morphology of the as-prepared samples were characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cyclic voltammogram (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS) techniques were employed to investigate the electrochemical performance of the composites. The PYMG electrode displayed specific capacitance as high as 596.3 Fg-1 at the current density of 0.5 Ag-1, which is much higher than that of polypyrrole/manganese dioxide (PPy/ MnO2 ) composite reported previously. The high specific capacitance of PYMG may be attributed to the fact that the porous GF is a good conductive matrix for the dispersion of PPy/ MnO2 composite and it can facilitate easy access of electrolytes to the electrode, which results in enhancement of the electrochemical performance of the composite. Furthermore, the PYMG composite exhibited enhanced specific capacitance compared to MnO2 /GF (MGF) and PPy/GF, which may be ascribed to the synergistic effect of PPy and MnO2 .

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.

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.

Synthesis and Characterization of Nanoflakes β-Ni(OH)2 Microspheres for Supercapacitors

2011 ◽  
Vol 230-232 ◽  
pp. 306-309 ◽  
Author(s):  
Zhan Jun Yu ◽  
Ying Dai ◽  
Wen Chen
Keyword(s):  
Specific Capacitance ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
X Ray Diffraction ◽  
Discharge Current Density ◽  
X Ray ◽  
A Charge ◽  
Maximum Specific Capacitance ◽  
Charge Discharge

Nanoflakes β-Ni(OH)2microspheres were successfully synthesized by a facile hydrothermal. The microstructures and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electrochemical properties studies were carried out using cyclic voltammetry (CV), galvanostaitc charge/discharge and electrochemical impedance spectroscopy methods, respectively. The results exhibited that the β-Ni(OH)2single electrode had high specific capacitance in KOH electrolyte. A maximum specific capacitance of 1929 F/g could be achieved in 6 M aqueous KOH with 0 to 0.4 V potential at a charge-discharge current density of 6 mA/cm2. Therefore, the obtained nanoflakes β-Ni(OH)2microspheres can be a potential application electrode material for supercapacitors.

Facile Synthesis of Co3O4/Nitrogen-Doped Graphene Composite with Enhanced Electrochemical Performance

2016 ◽  
Vol 847 ◽  
pp. 14-21 ◽  
Author(s):  
Hui Yun Tan ◽  
Zhao Yu Ren
Keyword(s):  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
Facile Synthesis ◽  
X Ray ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
Supercapacitor Performance ◽  
Synthesized Materials ◽  
Enhanced Electrochemical Performance

Co3O4 nanoflakes/N-doped graphene (NG) was synthesized through a facile two-step synthesis route. The phase composition and morphology of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS). It has been found that introduction of NG has effects on the morphology of Co3O4 and leads to a well distribution of Co3O4 nanoflakes. The electrochemical properties of as-synthesized materials were measured by cyclic voltammetry (CV), galvanostatic charge/discharge tests and electrochemical impedance spectroscopy (EIS). The composite presents an enhanced supercapacitor performance than the pristine Co3O4 nanoflakes, mainly due to the strong synergistic effect of the NG and Co3O4.

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