scholarly journals Influence of Fe and Ni Doped CuO Nanomaterials for High Performance Supercapacitors

2020 ◽  
Vol 32 (11) ◽  
pp. 2763-2772
Author(s):  
Palanisamy Revathi ◽  
Venkatachalam Ma nikandan ◽  
Panneerselvam Ezhilmathi ◽  
Veerasamy Uma Shankar ◽  
Palani Suganya ◽  
...  
Keyword(s):  
High Performance ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Charge Transfer Resistance ◽  
Cyclic Voltammograms ◽  
Transfer Resistance ◽  
Galvanostatic Discharge ◽  
Low Charge ◽  
Supercapacitor Applications ◽  
Eis Analysis

This paper focuses on the synthesis of doped and undoped CuO nanoparticles using the sol-gel method, which has been prepared and described. Supercapacitor applications of as-synthesized nanomaterials were analyzed using cyclic voltammetry (CV), galvanostatic discharge (GCD) and electrochemical impedance spectroscopic (EIS) analysis. The cyclic voltammograms illustrated the quasi-rectangular shape which depicted the pseudocapacitance nature of the samples. The calculated specific capacitance of the prepared samples was 180, 253 and 303 (F/g) corresponding to CuO, Fe-CuO and Ni-CuO, respectively at the low current density and the EIS spectra show that the prepared Ni-CuO electrode exhibits low charge transfer resistance.

Enhanced Electrochemical Performances of LiFePO4/C Cathode Materials by Deposited with Ge Film

2014 ◽  
Vol 936 ◽  
pp. 480-485
Author(s):  
Yan Dan Huang ◽  
Ying Bin Lin ◽  
Zhi Gao Huang
Keyword(s):  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Rate Capability ◽  
Film Surface ◽  
Charge Transfer Resistance ◽  
Electrochemical Performances ◽  
Cyclic Voltammograms ◽  
Transfer Resistance ◽  
Surface Modified

LiFePO4/C-Ge electrodes were prepared with vacuum thermal evaporation deposition by depositing Ge films on as-prepared LiFePO4/C electrodes. The effect of Ge film on the electrochemical performances of LiFePO4/C cells was investigated systematically by charge/discharge testing, cyclic voltammograms and AC impedance spectroscopy, respectively. It was found that Ge-film-surface modified LiFePO4/C showed excellent electrochemical performances compared to that of the pristine one in terms of cyclability and rate capability. At 60°C, LiFePO4/C-Ge film exhibited outstanding cyclability with less than 5% capacity fade after 50 cycles while the pristine one suffers 15%. Analysis from the electrochemical measurements showed that the presence of Ge film on the LiFePO4/C electrode would protect active material from HF generated by the decomposition of LiPF6 in the electrolyte and stabilize the surface structure of active material during the charge and discharge cycle. Electrochemical impedance spectroscopy (EIS) results indicated that Ge film mainly reduced the charge transfer resistance Rct of LiFePO4/C electrode, resulting from the suppression of the solid electrolyte interfacial (SEI) film.

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.

Effect of Plating Solutions on Supercapacitor Characteristics of MnO2 Films

2010 ◽  
Vol 113-116 ◽  
pp. 1810-1813
Author(s):  
Fang Xiao ◽  
You Long Xu
Keyword(s):  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Equivalent Circuit Model ◽  
Active Surface ◽  
Charge Transfer Resistance ◽  
Electrochemical Impedance Spectrum ◽  
Active Surface Area ◽  
Cyclic Voltammograms ◽  
Supercapacitor Electrode ◽  
Transfer Resistance

MnO2 films were electrodeposited on the Ti substrates by galvanostatic method in various plating solutions, which was MnCl2, Mn(NO3)2, MnSO4 and Mn(CH3COO)2 solutions, respectively. On X-ray diffraction test, Crystal structures of all MnO2 films were associated to α-MnO2 of tetragonal crystal system. Scanning electron microscopy results show that morphologies of MnO2 films were clearly different. Among them, MnO2 film prepared in Mn(CH3COO)2 solution presented a lot of cracks and holes. According to electrochemical impedance spectrum analysis, this MnO2 film presents the lowest charge-transfer resistance. Additionally, electrochemical active surface areas of MnO2 films were calculated on the basis of equivalent circuit model for impedance data. The result was found that MnO2 film prepared in Mn(CH3COO)2 solution showed the biggest electrochemical active surface area, which was about 382 cm2. Cyclic voltammograms were carried out for all the samples. MnO2 film formed in Mn(CH3COO)2 solution showed the highest special capacitance of 230 F g-1. The results suggest that Mn(CH3COO)2 solution is suitable for electrodepositing MnO2 film using supercapacitor electrode materials.

scholarly journals Synthesis of MoIn2S4@CNTs Composite Counter Electrode for Dye-Sensitized Solar Cells

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Gentian Yue ◽  
Renzhi Cheng ◽  
Xueman Gao ◽  
Leqing Fan ◽  
Yangfan Mao ◽  
...  
Keyword(s):  
Counter Electrode ◽  
Electrochemical Impedance ◽  
Dye Sensitized Solar Cells ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Electrochemical Tests ◽  
One Step ◽  
Low Charge ◽  
Adsorption Desorption ◽  
Sensitized Solar Cells

Abstract A ternary and composite MoIn2S4@CNTs counter electrode (CE) with a hedgehog ball structure was synthesized by using a facile one-step hydrothermal method. The composite MoIn2S4@CNTs film possesses large specific surface area through N2 adsorption-desorption isotherms test, which is advantageous to adsorb more electrolyte and provide larger active contact area for the electrode. In addition, the composite MoIn2S4@CNTs CE exhibits low charge transfer resistance and fine electrocatalytic ability made from a series of electrochemical tests including cyclic voltammetry, electrochemical impedance, and Tafel curves. Under optimal conditions, the DSSC based on the MoIn2S4@CNTs-2 composite CE achieves an impressive power conversion efficiency as high as 8.38%, which remarkably exceeds that of the DSSCs with the MoIn2S4 CE (7.44%) and the Pt electrode (8.01%). The current work provides a simplified preparation process for the DSSCs.

Polyaniline Binder for Functionalized Acetylene Black: A Hybrid Material for Supercapacitor

2014 ◽  
Vol 1024 ◽  
pp. 327-330
Author(s):  
Singh Ajit ◽  
Srinivasan Palaniappan ◽  
S. Gopukumar
Keyword(s):  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Acetylene Black ◽  
Transfer Resistance ◽  
Bonding Effect ◽  
Ft Ir ◽  
Xps Study ◽  
Low Charge ◽  
Electrochemical Impedance Spectroscopic ◽  
Thermal Stability Of

Polyaniline-doped with functionalyzed acetylene black material has been successfully synthesized and used as an electrode material in supercapacitor, wherein, this material contributes both pseudocapacitative (PC) and electrical double layer capacitative (EDLC) behaviour. Functionalization of acetylene black (AB) has been carried out and used as dopant for THF soluble polyaniline base (PANI) to prepare PANI-functionalized acetylene black (PANI-FAB). Formation of FAB and PANI-FAB was confirmed with the help of FT-IR and XPS study. Functionalization of AB results in agglomerated FAB and doping with PANI results in agglomerated fibrous PANI-FAB, as compared to fibrous AB. High thermal stability of AB decreases on functionalization and again slightly increases for PANI-FAB. Functionalization of AB also results good bonding effect with PANI, where PANI acts as both PC and binder, instead of the higher amounts of binder (PVdF > 30 wt%) that are normally needed to hold AB. Electrochemical studies of FAB and PANI-FAB materials were carried out by cyclic voltammetric and electrochemical impedance spectroscopic methods. PANI-FAB supercapacitor cell shows capacitance of 132 Fg1for 0.3 Ag1current density with very low charge-transfer resistance and low time constant.

scholarly journals Bioleaching and Electrochemical Behavior of Chalcopyrite by a Mixed Culture at Low Temperature

2021 ◽  
Vol 12 ◽  
Author(s):  
Tangjian Peng ◽  
Wanqing Liao ◽  
Jingshu Wang ◽  
Jie Miao ◽  
Yuping Peng ◽  
...  
Keyword(s):  
Low Temperature ◽  
Mixed Culture ◽  
Pure Culture ◽  
High Throughput Sequencing ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Charge Transfer Resistance ◽  
Microbial Consortia ◽  
Cyclic Voltammograms ◽  
Transfer Resistance

Low-temperature biohydrometallurgy is implicated in metal recovery in alpine mining areas, but bioleaching using microbial consortia at temperatures <10°C was scarcely discussed. To this end, a mixed culture was used for chalcopyrite bioleaching at 6°C. The mixed culture resulted in a higher copper leaching rate than the pure culture of Acidithiobacillus ferrivorans strain YL15. High-throughput sequencing technology showed that Acidithiobacillus spp. and Sulfobacillus spp. were the mixed culture’s major lineages. Cyclic voltammograms, potentiodynamic polarization and electrochemical impedance spectroscopy unveiled that the mixed culture enhanced the dissolution reactions, decreased the corrosion potential and increased the corrosion current, and lowered the charge transfer resistance and passivation layer impedance of the chalcopyrite electrode compared with the pure culture. This study revealed the mechanisms via which the mixed culture promoted the chalcopyrite bioleaching.

scholarly journals High performance of solvothermally prepared VO2(B) as anode for aqueous rechargeable lithium batteries

2015 ◽  
Vol 80 (5) ◽  
pp. 685-694 ◽  
Author(s):  
Sanja Milosevic ◽  
Ivana Stojkovic ◽  
Miodrag Mitric ◽  
Nikola Cvjeticanin
Keyword(s):  
Discharge Capacity ◽  
High Performance ◽  
Electronic Conductivity ◽  
Charge Transfer Resistance ◽  
Initial Discharge Capacity ◽  
Rechargeable Lithium Batteries ◽  
Transfer Resistance ◽  
Initial Discharge ◽  
The Stability ◽  
Low Charge

The VO2 (B) was synthesized via a simple solvothermal route at 160oC in ethanol. The initial discharge capacity of VO2 (B) anode, in saturated aqueous solution of LiNO3, was 177 mAh g-1 at a current rate of 50 mA g-1. After 50 cycles capacity fade was 4%, but from 20th-50th cycle no capacity drop was observed. The VO2 (B) has shown very good cyclability at current rate of even 1000 mA g-1 with initial discharge capacity of 92 mAh g-1. The excellent electrochemical performance of VO2 (B) was attributed to the stability of micro-nano structures to repeated intercalation /deintercalation process, very good electronic conductivity as well as the very low charge transfer resistance in the aqueous electrolyte.

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