Electrochemical Performance of Activated Carbon Electrode Added with LiCoO2 for Hybrid Capacitor

2007 ◽  
Vol 124-126 ◽  
pp. 947-950 ◽  
Author(s):  
Ick Jun Kim ◽  
Min Je Jeon ◽  
Sun Hye Yang ◽  
Seong In Moon ◽  
Hyun Soo Kim
Keyword(s):  
Particle Size ◽  
Activated Carbon ◽  
Size Effect ◽  
Electrochemical Performance ◽  
Electrochemical Properties ◽  
Ball Milling ◽  
Active Material ◽  
Carbon Electrode ◽  
Volumetric Capacity ◽  
Charge Discharge

In this study, mixed active material electrodes, composed of an activated carbon (MSP20) and LiCoO2, were prepared as cathodes for a high-capacitive hybrid capacitor. The electrochemical properties of (MSP20+LiCoO2)/Li cells were examined in terms of the weight composition and the particle size of LiCoO2 powder in the electrodes. As adding more LiCoO2 powders in the electrode, the volumetric capacity (mAh/ml) of the electrode became higher. In order to examine the size effect on the electrochemical performance, the LiCoO2 powders were modified by ball milling. The (MSP20+LiCoO2)/Li cells using 10 and 20 wt.% of 30h-milled LiCoO2 powder exhibited the lower internal resistivities and the better capacity retentions after 100 charge-discharge cycles than those using 10 or 20 wt.% of raw LiCoO2 powders.

Probing the Effect of High Energy Ball Milling on the Structure and Properties of LiNi1/3Mn1/3Co1/3O2 Cathodes for Li-Ion Batteries

2016 ◽  
Vol 13 (3) ◽  
Author(s):  
Malcolm Stein ◽  
Chien-Fan Chen ◽  
Matthew Mullings ◽  
David Jaime ◽  
Audrey Zaleski ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrochemical Performance ◽  
Crystallite Size ◽  
Ball Milling ◽  
Lithium Ion ◽  
High Energy ◽  
Li Ion Batteries ◽  
Structure And Properties ◽  
Transfer Resistance ◽  
Li Ion

Particle size plays an important role in the electrochemical performance of cathodes for lithium-ion (Li-ion) batteries. High energy planetary ball milling of LiNi1/3Mn1/3Co1/3O2 (NMC) cathode materials was investigated as a route to reduce the particle size and improve the electrochemical performance. The effect of ball milling times, milling speeds, and composition on the structure and properties of NMC cathodes was determined. X-ray diffraction analysis showed that ball milling decreased primary particle (crystallite) size by up to 29%, and the crystallite size was correlated with the milling time and milling speed. Using relatively mild milling conditions that provided an intermediate crystallite size, cathodes with higher capacities, improved rate capabilities, and improved capacity retention were obtained within 14 μm-thick electrode configurations. High milling speeds and long milling times not only resulted in smaller crystallite sizes but also lowered electrochemical performance. Beyond reduction in crystallite size, ball milling was found to increase the interfacial charge transfer resistance, lower the electrical conductivity, and produce aggregates that influenced performance. Computations support that electrolyte diffusivity within the cathode and film thickness play a significant role in the electrode performance. This study shows that cathodes with improved performance are obtained through use of mild ball milling conditions and appropriately designed electrodes that optimize the multiple transport phenomena involved in electrochemical charge storage materials.

Electrochemical Properties of Carbon-Coated NbO2 as a Negative Electrode for Lithium-Ion Batteries

2016 ◽  
Vol 724 ◽  
pp. 87-91 ◽  
Author(s):  
Chang Su Kim ◽  
Yong Hoon Cho ◽  
Kyoung Soo Park ◽  
Soon Ki Jeong ◽  
Yang Soo Kim
Keyword(s):  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Ball Milling ◽  
Carbon Coating ◽  
Electrochemical Impedance ◽  
Active Material ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Transfer Resistance ◽  
Carbon Coated

We investigated the electrochemical properties of carbon-coated niobium dioxide (NbO2) as a negative electrode material for lithium-ion batteries. Carbon-coated NbO2 powders were synthesized by ball-milling using carbon nanotubes as the carbon source. The carbon-coated NbO2 samples were of smaller particle size compared to the pristine NbO2 samples. The carbon layers were coated non-uniformly on the NbO2 surface. The X-ray diffraction patterns confirmed that the inter-layer distances increased after carbon coating by ball-milling. This lead to decreased charge-transfer resistance, confirmed by electrochemical impedance spectroscopy, allowing electrons and lithium-ions to quickly transfer between the active material and electrolyte. Electrochemical performance, including capacity and initial coulombic efficiency, was therefore improved by carbon coating by ball-milling.

Investigation of the Mechanism of Small Size Effect in Carbon-based Supercapacitors

Nanoscale ◽  
2021 ◽  
Author(s):  
Chenyang Zhao ◽  
Chengyao Zhao ◽  
Qi Liu ◽  
Xiaohui Liu ◽  
Xiaotong Lu ◽  
...  
Keyword(s):  
Size Effect ◽  
Electrochemical Performance ◽  
Electrode Materials ◽  
Carbon Electrode ◽  
Carbon Based

Small size effect could be conducive to enhancing the electrochemical performance, while the mechanism by which they also increase the capacitance for carbon electrode materials has not been established. Here,...

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.

Microporous Carbon-halide Nanocomposites Electrodes for Symmetric and Asymmetric Capacitor

2008 ◽  
Vol 1100 ◽  
Author(s):  
Prabeer Barpanda ◽  
Giovanni Fanchini ◽  
Glenn G Amatucci
Keyword(s):  
Activated Carbon ◽  
Electrochemical Performance ◽  
Electrochemical Properties ◽  
Vapor Phase ◽  
Mesoporous Carbon ◽  
Microporous Carbon ◽  
Chemically Modified ◽  
Asymmetric Capacitor ◽  
Carbon System ◽  
Asymmetric Capacitors

AbstractMicroporous carbon containing little mesoporosity was chemically modified through a vapor phase iodation treatment in an effort to improve the electrochemical performance of activated carbon system commonly utilized in symmetric and asymmetric capacitors. This new carbon system has been studied with respect to their structural, morphological and electrochemical properties and contrasted to the mesoporous carbon based nanocomposites.

Preparation of Nano-spherical Iron Phosphate by Hydrothermal Method and Its Application as the Precursor of Lithium Iron Phosphate

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Ju Guo ◽  
Fuyong Wu
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Electrochemical Performance ◽  
Hydrothermal Method ◽  
Carbon Coating ◽  
Specific Capacity ◽  
Iron Phosphate ◽  
X Ray ◽  
Spherical Morphology ◽  
Charge Discharge

Abstract First, nano-spherical iron phosphate was prepared using the hydrothermal method. Then, the carbothermal reduction method was applied to synthesize the LiFePO4/C composite material capable of good carbon coating effect with the prepared nano-spherical iron phosphate as a precursor. By means of scanning electron microscope, transmission electron microscope, Zeta potentiometer, inductively coupled plasma spectrometer, X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical testing, and other methods, the material was characterized and tested for its morphology, particle size, composition, structure, and electrochemical performance. According to the test results, when the initial mass concentration of Fe3+ in the reaction solution is 2%, the amount of N and S impurity is merely 19 and 27 ppm, respectively. In the meantime, particle size is small, with a range of roughly 50–100 nm, and a spherical morphology is shown. The synthesized LiFePO4/C retains its nano-spherical morphology, which leads to a desirable carbon coating effect and an excellent electrochemical performance. The first charge–discharge specific capacity at 0.1 C rate reached 163.7 and 161.4 mAh/g, the charge–discharge efficiency was 98.6%, and the capacity retention rate at 50 charge–discharge cycles at 1 C rate reached 98.52%.

Effect of Ball Milling Process on Electrochemical Properties of Copper Hexacyanoferrate Active Material for Calcium-Ion Batteries

2019 ◽  
Vol 803 ◽  
pp. 109-114
Author(s):  
Ha Jin Lee ◽  
Du Yeol Kim ◽  
Soon Ki Jeong
Keyword(s):  
Electrochemical Properties ◽  
Ball Milling ◽  
Calcium Ion ◽  
Crystal Surface ◽  
Active Material ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Copper Hexacyanoferrate ◽  
Sem Images ◽  
Ball Milling Process

This study investigates the electrochemical properties of ball-milled copper hexacyanoferrate (CuHCF), a Prussian blue analogue, as a cathode material in aqueous calcium-ion batteries (CIBs). X-ray diffraction analysis confirmed that the ball milling process did not destroy the crystal structure of the CuHCF active material. The general grain size and crystal surface of the synthesized CuHCF active materials were confirmed from the scanning electron microscopy (SEM) images. The electrochemical test results revealed that prolonged ball milling improved the charge/discharge capacity in the initial cycle. After 200 cycles, structural collapse of the CuHCF electrode occurred, as observed by SEM.

scholarly journals Electrochemical Properties of PANI as Single Electrode of Electrochemical Capacitors in Acid Electrolytes

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Haihua Zhu ◽  
Shunjin Peng ◽  
Weijie Jiang
Keyword(s):  
Electrochemical Properties ◽  
Chemical Structure ◽  
Active Material ◽  
Electrochemical Capacitor ◽  
Current Collector ◽  
Carbon Paper ◽  
Solution Polymerization ◽  
Chemical Solution ◽  
Galvanostatic Charge ◽  
Charge Discharge

The polyaniline (PANI) powder with globular sponge-like morphology was prepared by chemical solution polymerization, and its morphology and chemical structure were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. The single electrode of electrochemical capacitor was made using the prepared PANI powder as active material and carbon paper as current collector. Electrochemical properties of PANI as a single electrode in 1 M HCl and 1 M H2SO4electrolyte solution were tested by galvanostatic charge/discharge (GCD) and cyclic voltammetry (CV) techniques. It has been found that PANI has higher specific capacitance of 302.43 Fg−1, higher specific energy of 54.44 Wh·kg−1at 0.5 Ag−1, and higher working potential in 1 M HCl than those in 1 M H2SO4.

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