scholarly journals Electrochemical Performance of 2D-Hierarchical Sheet-Like ZnCo2O4 Microstructures for Supercapacitor Applications

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 566 ◽  
Author(s):  
Kumcham Prasad ◽  
Gutturu Rajasekhara Reddy ◽  
Megala Rajesh ◽  
P. Reddi Babu ◽  
Gnanendra Shanmugam ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Global Economy ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Cycling Performance ◽  
Utilization Rate ◽  
Rapid Improvement ◽  
Areal Capacitance ◽  
Supercapacitor Applications

With the rapid improvement of the global economy, the role of energy has become even more vital in the 21st century. In this regard, energy storage/conversion devices have become a major, worldwide research focus. In response to this, we have prepared two-dimensional (2D)-hierarchical sheet-like ZnCo2O4 microstructures for supercapacitor applications using a simple hydrothermal method. The 2D-hierarchical sheet-like morphologies with large surface area and smaller thickness enhanced the contact area of active material with the electrolyte, which increased the utilization rate. We investigated the electrochemical performance of sheet-like ZnCo2O4 microstructures while using Cyclic voltammetry (CV), Galvanostatic charge-discharge (GCD), and Electrochemical impedance spectroscopy (EIS) analysis. The electrochemical results demonstrated that the ZnCo2O4 electrode possesses 16.13 mF cm−2 of areal capacitance at 10 µA cm−2 of current density and outstanding cycling performance (170% of capacitance is retained after 1000 cycles at 500 µA cm−2). The high areal capacitance and outstanding cycling performance due to the unique sheet-like morphology of the ZnCo2O4 electrode makes it an excellent candidate for supercapacitor applications.

scholarly journals Optical and Electrochemical Applications of Li-Doped NiO Nanostructures Synthesized via Facile Microwave Technique

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2961 ◽  
Author(s):  
Aarti S. Bhatt ◽  
R. Ranjitha ◽  
M. S. Santosh ◽  
C. R. Ravikumar ◽  
S. C. Prashantha ◽  
...  
Keyword(s):  
Optical Band Gap ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Nio Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Technique ◽  
Electro Optic ◽  
Li Ion ◽  
Supercapacitor Applications

Nanostructured NiO and Li-ion doped NiO have been synthesized via a facile microwave technique and simulated using the first principle method. The effects of microwaves on the morphology of the nanostructures have been studied by Field Emission Spectroscopy. X-ray diffraction studies confirm the nanosize of the particles and favoured orientations along the (111), (200) and (220) planes revealing the cubic structure. The optical band gap decreases from 3.3 eV (pure NiO) to 3.17 eV (NiO doped with 1% Li). Further, computational simulations have been performed to understand the optical behaviour of the synthesized nanoparticles. The optical properties of the doped materials exhibit violet, blue and green emissions, as evaluated using photoluminescence (PL) spectroscopy. In the presence of Li-ions, NiO nanoparticles exhibit enhanced electrical capacities and better cyclability. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results show that with 1% Li as dopant, there is a marked improvement in the reversibility and the conductance value of NiO. The results are encouraging as the synthesized nanoparticles stand a better chance of being used as an active material for electrochromic, electro-optic and supercapacitor applications.

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.

scholarly journals Effects of In Situ Graphitic Nanocarbon Coatings on Cycling Performance of Silicon-Flake-Based Anode of Lithium Ion Battery

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 138
Author(s):  
Yonhua Tzeng ◽  
Wei-Chih Huang ◽  
Cheng-Ying Jhan ◽  
Yi-Hsuan Wu
Keyword(s):  
Lithium Ion Battery ◽  
Electrochemical Impedance ◽  
Iron Catalyst ◽  
Active Material ◽  
Lithium Ion ◽  
Chemical Vapor ◽  
Cycling Performance ◽  
Carbon Films ◽  
Conductivity Enhancement ◽  
Wafer Manufacturing

We coated graphitic nanocarbons by thermal chemical vapor deposition (CVD) on silicon flakes recycled from the waste of silicon wafer manufacturing processes as an active material for the anode of lithium ion battery (LIB). Ferrocene contains both iron catalyst and carbon, while camphor serves as an additional carbon source. Water vapor promotes catalytic growth of nanocarbons, including carbon nanotubes (CNTs), carbon fibers (CFs), and carbon films made of graphitic carbon nanoparticles, at temperatures ranging from 650 to 850 °C. The container of silicon flakes rotates for uniform coatings on silicon flakes of about 100 nm thick and 800–1000 nm in lateral dimensions. Due to short CVD time, besides CNTs and CFs, surfaces of silicon flakes deposit with high-density graphitic nanoparticles, especially at a low temperature of 650 °C. Nanocarbon coatings were characterized by SEM, EDX, ESCA, and Raman spectroscopy. Half-cells were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and retention of capacity in discharge/charge cycling. Silicon-flake-based anode with nanocarbon coatings at both 650 and 850 °C exhibited capacity retention of 2000 mAh/g after 100 cycles at 0.1 C, without needing any conductivity enhancement material such as Super P.

scholarly journals The Role of the Binder/Solvent Pair on the Electrochemical Performance of Aluminium Batteries

MRS Advances ◽  
2019 ◽  
Vol 4 (14) ◽  
pp. 807-812 ◽  
Author(s):  
Jasmin Smajic ◽  
Amira Alazmi ◽  
Pedro M. F. J. Costa
Keyword(s):  
Graphene Oxide ◽  
Energy Storage ◽  
Electrochemical Performance ◽  
Carboxymethyl Cellulose ◽  
Polyvinylidene Fluoride ◽  
Storage Systems ◽  
Active Material ◽  
Aluminium Chloride ◽  
Reduced Graphene

ABSTRACTIn energy storage systems, every component that makes up an electrode can greatly affect the electrochemical performance. One example includes the so-called “binders” used in secondary batteries. Herein, we compare the influence of using polyvinylidene fluoride (PVDF) or sodium carboxymethyl cellulose (CMC) on the electrochemical performance of an aluminium chloride battery (ACB) system. The active material of the cathode was a reduced graphene oxide dried under supercritical conditions (RGOCPD). Interestingly, while PVDF enabled one of the highest capacities reported for ACBs, the CMC resulted in a significant degradation of the cell’s performance.

Improved electrochemical performance of LiNi0.8Co0.15Al0.05O2/LiMn1∕3Ni1∕3Co1∕3O2 with core-shell structure synthesized by a coprecipitation and spray pyrolysis process

2018 ◽  
Vol 11 (04) ◽  
pp. 1850083 ◽  
Author(s):  
Hongyong Ouyang ◽  
Xinhai Li ◽  
Zhixing Wang ◽  
Huajun Guo ◽  
Wenjie Peng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Spray Pyrolysis ◽  
Electrochemical Impedance ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Core Shell ◽  
Pyrolysis Process ◽  
Spray Pyrolysis Process

Core-shell composite material LiNi[Formula: see text]Co[Formula: see text]Al[Formula: see text]O2/LiMn[Formula: see text]Ni[Formula: see text]Co[Formula: see text]O2 (NCA/NCM) was synthesized via a coprecipitation and spray pyrolysis process. The properties of pristine LiNi[Formula: see text]Co[Formula: see text]Al[Formula: see text]O2 (NCA) and Core-shell NCA/NCM were investigated by scanning electron microscopy, transmission electron microscopy, Galvanostatic cell cycling and electrochemical impedance spectroscopy. Results showed that the Core-shell NCA/NCM exhibited enhanced rate capability and cycling performance than the pristine NCA. The improved electrochemical performance is due to the fact that the NCM layer can stabilize the crystal structure of materials and suppress the deterioration of lithium ion diffusing ability during electrode process.

Cobalt ion-doped polyaniline, poly(N-methylaniline), and poly(N-ethylaniline): electrosynthesis and characterisation using electrochemical methods in acidic solutions

2014 ◽  
Vol 68 (11) ◽  
Author(s):  
Evrim Hur ◽  
Andac Arslan
Keyword(s):  
Low Voltage ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Electrochemical Methods ◽  
Pencil Graphite Electrode ◽  
Cobalt Ion ◽  
Acidic Solutions ◽  
Doped Polyaniline ◽  
Eis Measurements ◽  
Supercapacitor Applications

AbstractCobalt ion (Co2+)-doped polyaniline (PANI-Co), poly(N-methylaniline) (PNMA-Co), and poly(N-ethylaniline) (PNEA-Co) films were synthesised electrochemically on a pencil graphite electrode (PGE) and their electrochemical properties were investigated for supercapacitor applications. The polymer film-coated electrodes (PGE/PANI-Co, PGE/PNMA-Co, and PGE/PNEA-Co) thus obtained were characterised by scanning electron microscopy (SEM) and different electrochemical methods. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements were employed in 0.1 M H2SO4 solution to calculate the specific capacitance (C S) values of the electrodes. The maximum C S of 192.94 F g−1, 139.83 F g−1, and 47.12 F g−1 were achieved for PGE/PANI-Co, PGE/PNMA-Co, and PGE/PNEA-Co at 1 mV s−1, respectively. On the other hand, the charge/discharge stability of the electrodes was analysed using the repeating chronopotentiometry (RCP) method. The RCP measurements indicate that the electrodes could be used as an electrode active material for low voltage supercapacitor applications.

Electrochemical Performance of Li3V2 (PO4)3/C Cathode Material Prepared by Soft Chemistry Route

2010 ◽  
Vol 129-131 ◽  
pp. 521-525 ◽  
Author(s):  
Feng Wang ◽  
Feng Wu ◽  
Chuan Wu ◽  
Ying Bai ◽  
Lian Wang
Keyword(s):  
Electrochemical Performance ◽  
Cathode Material ◽  
Electrochemical Impedance ◽  
Chemical Diffusion ◽  
Reversible Capacity ◽  
Cycling Performance ◽  
High Rate ◽  
Chemical Diffusion Coefficient ◽  
X Ray Diffraction ◽  
Soft Chemistry

Monoclinic Li3V2 (PO4)3/C cathode material has been synthesized by soft chemistry route and the electrochemical performance of this material was investigated. The structure of the particles was characterized by X-ray diffraction (XRD). The Li3V2 (PO4)3/C composite exhibits good cycling performance and excellent rate capabilities when cycled between 3.0 and 4.3 V. At 1C rate, the cell displays a reversible capacity of 117 mAh/g and retains 98.1 % of its initial discharge capacity after 50 cycles. At the high rate of 5C, the capacity could reach 109 mAh/g, corresponding to 93 % of that at 0.5C. Electrochemical impedance spectroscopy (EIS) technique was used to analyze the chemical diffusion coefficient of Li.

The Role of Technological Change in the Long-run Global Economy Forecasting

2013 ◽  
pp. 97-116 ◽  
Author(s):  
A. Apokin
Keyword(s):  
Technological Change ◽  
Data Quality ◽  
Long Range ◽  
Global Economy ◽  
World Economy ◽  
Qualitative Approaches ◽  
Long Run ◽  
The World ◽  
National Economies

The author compares several quantitative and qualitative approaches to forecasting to find appropriate methods to incorporate technological change in long-range forecasts of the world economy. A?number of long-run forecasts (with horizons over 10 years) for the world economy and national economies is reviewed to outline advantages and drawbacks for different ways to account for technological change. Various approaches based on their sensitivity to data quality and robustness to model misspecifications are compared and recommendations are offered on the choice of appropriate technique in long-run forecasts of the world economy in the presence of technological change.

INTERACTION OF THE NATIONAL ECONOMY OF UKRAINE WITH INTERNATIONAL CREDIT AND FINANCIAL ORGANIZATIONS

2017 ◽  
Author(s):  
Serhii Voitko ◽  
◽  
Yuliia Borodinova ◽  
Keyword(s):  
Financial Institutions ◽  
National Economy ◽  
Financial Support ◽  
Global Economy ◽  
Financial Sector ◽  
Negative Consequences ◽  
International Financial Institutions ◽  
The Future ◽  
International Credit

The article examines the interaction of the national economy of Ukraine with international credit and financial organizations, evaluates the positive and negative consequences and identifies possible areas for further cooperation. The role of international credit and financial organizations in the development of the global economy is analyzed. Today, international financial institutions have taken a leading place among institutions that provide financial support and contribute to the implementation of necessary reforms aimed at developing enterprises in various sectors of the economy and strengthening the country's financial sector as a whole. The importance of cooperation between Ukraine and international financial institutions for the development of the country's economy has been determined. The problems and directions of development of cooperation with leading credit and financial organizations in modern conditions are identified. Despite the presence of certain shortcomings, cooperation between Ukraine and international credit and financial organizations will continue in the future.

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