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.

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.

Synthesis of NiFe2O4 Nanoparticles and its Supercapacitive Properties

2013 ◽  
Vol 275-277 ◽  
pp. 1733-1736 ◽  
Author(s):  
Zi Tao Yang ◽  
Bo Wen Cheng ◽  
Yong Nan Zhao
Keyword(s):  
Water Solution ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Transmission Electron ◽  
Nife2o4 Nanoparticles ◽  
Diffraction Peaks ◽  
Xrd Patterns ◽  
Charge Discharge

NiFe2O4 nanoparticles was successfully synthesized by hydrothermal decomposition of a gel of Ni-Fe-EG (EG=ethylene glycol) in water solution. The crystal structure and morphologies of the products were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). All the diffraction peaks in XRD patterns revealed that the as-synthesized nanoparticles were pure NiFe2O4. TEM images disclosed that the particle sizes of the nanoparticles were in the range of 10 − 25nm. The cyclic voltammetry (CV) and galvanostatic charge/discharge results tested in 6M KOH solution revealed a double layer capacitive behavior and a revisable charge/discharge property.

Synthesis of BCN Nanoparticles Sandwiched between Carbon Nanosheets and Performance in Electrochemical Capacitors

2015 ◽  
Vol 719-720 ◽  
pp. 137-140
Author(s):  
Ren Li Yang ◽  
Jun Shuang Zhou ◽  
Li Hou ◽  
Yu Feng Zhao ◽  
Fa Ming Gao
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Current Density ◽  
Nitrogen Atmosphere ◽  
Galvanostatic Charge ◽  
Carbon Nanosheets ◽  
And Performance ◽  
Discharge Measurements ◽  
Charge Discharge

BCN nanoparticles sandwiched between carbon nanosheets were synthesized with the P123 and borate ammonium under nitrogen atmosphere. The samples were characterized by SEM, TEM, and EELS. The SEM and TEM images show BCN nanoparticles are attached on the carbon nanosheets. Cyclic voltammetry (CV) and galvanostatic charge-discharge measurements are used to evaluate electrochemical properties of the composites. The samples show the specific capacitance of 102 F/g at current density of 200mA/g and good durability.

Thermal Decomposition Synthesis of MoO3 for Application in Electrochemical Supercapacitors

2014 ◽  
Vol 1008-1009 ◽  
pp. 361-364 ◽  
Author(s):  
Xiao Ping Zhou ◽  
Lin Ma ◽  
Xu Yao Xu ◽  
Zong Cai Feng
Keyword(s):  
Thermal Decomposition ◽  
Decomposition Temperature ◽  
Ammonium Molybdate ◽  
Electrochemical Supercapacitors ◽  
Thermal Decomposition Temperature ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Charge Discharge ◽  
Scanning Electron

MoO3was synthesized by thermal decomposition of ammonium molybdate. The structure and surface morphology of the as-prepared MoO3was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The supercapacitive behaviour of MoO3in 1 mol L-1KCl electrolyte was studied by cyclic voltammetry (CV), galvanostatic charge-discharge cycling (CD). The affect of thermal decomposition temperature on the capacitive behaviour of MoO3was also discussed here. The results indicate that MoO3show good capacitive behaviour with a specific capacitance of 148.9 F g-1at 0.7 A g-1. Thermal decomposition temperature has an important influence on the capacitive behaviour and crystallization of MoO3.

Preparation of Co-Ni Mixed Oxide/Graphene Composite and its Electrochemical Performances as Supercapacitor Material

2017 ◽  
Vol 727 ◽  
pp. 775-780 ◽  
Author(s):  
Yun Long Zhou ◽  
Chen Hao Zhao ◽  
Zhi Biao Hu ◽  
Xue Yan Huang ◽  
Kai Yu Liu ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Mixed Oxides ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Graphene Composite ◽  
A Current ◽  
Charge Discharge ◽  
Discharge Test

The Co-Ni mixed oxides/graphene composite has been prepared using the solution based oxidation route. The structures of bare Co-Ni mixed oxides and Co-Ni mixed oxides/graphene composite is clearly studied by X-ray diffraction. The electrochemical properties of Co-Ni mixed oxides/graphene composite are investigated by Cyclic Voltammetry (CV) and galvanostatic charge discharge test. The result shows that, the NiO phase has not been detected in the composite, and the graphene composite delivers a discharge capacity of 353.6 F/g at a current density of 0.32 A g-1.

Surface Modification of LiCo1/3Ni1/3Mn1/3O2 with LaF3 for Lithium-Ion Batteries

2011 ◽  
Vol 399-401 ◽  
pp. 1515-1518
Author(s):  
Zhan Xu Yang ◽  
Qing Dong Qiao
Keyword(s):  
Coating Layer ◽  
Specific Capacity ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Discharge Specific Capacity ◽  
Initial Discharge ◽  
Surface Modified ◽  
Charge Discharge

LiCo1/3Ni1/3Mn1/3O2 has been modified with LaF3. The surface modified materials were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and galvanostatic charge-discharge cycling. The LaF3-coated LiCo1/3Ni1/3Mn1/3O2 had an initial discharge specific capacity of 178.0 mAh•g–1 within the potential ranges 2.75–4.5 V (vs. Li+/Li), and its discharge specific capacity is 168.7 mAh•g–1 after 50 cycles, much higher than that of the pristine LiCo1/3Ni1/3Mn1/3O2 (148.4 mAh•g–1). The improvement could be attributed to the LaF3 coating layer that hinders interaction between LiCo1/3Ni1/3Mn1/3O2 and electrolyte and stabilizes the structure of LiCo1/3Ni1/3Mn1/3O2 .

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.

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.

Preparation and Electrochemical Properties of VO2(B) Nano-Belts

2011 ◽  
Vol 694 ◽  
pp. 91-97
Author(s):  
Yu Long Qiao ◽  
Yong Jun Ma ◽  
Qing Ping Luo ◽  
Chong Hua Pei
Keyword(s):  
Cyclic Voltammetry ◽  
Energy Loss ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Monoclinic Phase ◽  
Galvanostatic Charge ◽  
Crystal Direction ◽  
Electron Energy Loss ◽  
Charge Discharge

The VO2(B) nanobelts with monoclinic phase were synthesized by a hydrothermal method at 220°C for 48 h in the absence of any surfactants. The electron energy loss spectrum (EELS) demonstrates that vanadium exists only in the 4+ oxidation state. The SEM and TEM images reveal a belt-like structure of the VO2(B) with the length of several micrometers, the width of 140 nm and the thickness of around 20nm and growth along the [110] crystal direction. Cyclic voltammetry (CV) and galvanostatic charge/discharge demonstrate that VO2(B) nano-belts electrode exhibits desirable electrochemical properties and the specific capacitance reaches up to 632.6F•g-1.

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