• Carbon letters
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• 제12권4호
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• pp.243-248
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• 2011

Two different types of graphite, such as flake graphite (FG) and spherical graphite (SG), were used as anode materials for a lithium-ion secondary battery in order to investigate their electrochemical performance. The FG particles were prepared by pulverizing natural graphite with a planetary mill. The SG particles were treated by immersing them in acid solutions or mixing them with various carbon additives. With a longer milling time, the particle size of the FG decreased. Since smaller particles allow more exposure of the edge planes toward the electrolyte, it could be possible for the FG anodes with longer milling time to deliver high reversible capacity; however, their initial efficiency was found to have decreased. The initial efficiency of SG anodes with acid treatments was about 90%, showing an over 20% higher value than that of FG anodes. With acid treatment, the discharge rate capability and the initial efficiency improved slightly. The electrochemical properties of the SG anodes improved slightly with carbon additives such as acetylene black (AB), Super P, Ketjen black, and carbon nanotubes. Furthermore, the cyclability was much improved due to the effect of the conductive bridge made by carbon additives such as AB and Super P.

• Journal of Power System Engineering
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• 제17권1호
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• pp.104-109
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• 2013

Tin and Tinoxide nanoparticles were prepared by arc-discharge nanopowder process. The negative electrode were fabricated using Tin and Tinoxide nanopower. The microstructure and electrochemistry properties were investigated and compared between Tin and Tinoxide. The oxidation film has microstructure of core/shell type and the shell which was attached around Tin nanoparticle consisted of amorphous $SnO_2$. The shape of Tinoxide nanoparticles was formed with irregular shape in comparison with Tin particle. Initial discharge capcity of Tinoxide electrode possesed about 1000mAh/g, which is about 320mAh/g higher than Tin electrode. Irreversible capacity of Tin electrode is much higher than Tinoxide. The cycle performance of Tinoxide electrode was indicated that is batter than Tin. The Tin negative electrode lost most of capacity after 4 cycle but Tinoxide electrode still retained the capacity. The Tinoxide does show some promise as Li-ion battery anode due to their large reversible capacity at low potentials.

• Journal of Electrochemical Science and Technology
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• 제7권3호
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• pp.228-233
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• 2016

It is hard to employ the carbon materials or the lithium metal foil for the anode of lithium sulfur batteries because of the poor passivation in ether-based electrolytes and the formation of lithium dendrites, respectively. Herein, we investigated the electrochemical characteristics of lithium sulfur batteries with lithiated silicon anode in the liquid electrolytes based on ether solvents. The silicon anodes were lithiated by direct contact with lithium foil in a 1M lithium bis(trifluoromethane sulfonyl) imide (LiTFSI) solution in 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL) at a volume ratio of 1:1. They were readily lithiated up to ~40% of their theoretical capacity with a 30 min contact time. In particular, the carbon mesh reported in our previous work was employed in order to maximize the performance by capturing the dissolved polysulfide in sulfur cathode. The reversible specific capacity of the lithiated silicon-sulfur batteries with carbon mesh was 1,129 mAh/g during the first cycle, and was maintained at 297 mAh/g even after 50 cycles at 0.2 C, without any problems of poor passivation or lithium dendrite formation.

• Journal of Hydrogen and New Energy
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• 제22권5호
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• pp.592-598
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• 2011

Electrode of solid oxide fuel cell must have sufficient porosity to allow gas transport to the interface with electrolyte effectively but high porosity has a negative impact on structural stability in electrode support. Thus, the upper limit of porosity is based on consideration of mechanical strength of electrode. In this study, the effect of microstructure of Ni-YSZ anode supported SOFC on the mechanical and electrical property was investigated. LSCF composite cathode and 8YSZ electrolyte were used. The porosity of the anode was modified by the amount of graphite powder and added graphite contents were 24, 18, 12 vol%, respectively. The higher the porosity, the better the electrical performance, $P_{max}$. While the flexural strength decreased with increasing the amount of graphite. But the rate of increase in electrical performance and the rate of decrease in mechanical strength were not directly proportional to amount of graphite. The optimum graphite content incorporating both electrical and mechanical performance was 18 vol%.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.268-268
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• 2010

The performance dependence of the P3HT:PCBM based bulk hetero-junction (BHJ) organic solar cells (OSCs) on the electrical and the optical properties of amorphous InZnSnO (a-IZTO) electrodes as a difference in film thicknesses are examined. With an increasing of the a-IZTO thickness, the series resistance ($R_{series}$) of the OSCs is reduced because of the reduction of sheet resistance ($R_{sheet}$) of a-IZTO electrodes. Additionally, It was found that the photocurrent density ($J_{sc}$) and the fill factor (FF) in OSCs are mainly affected by the electrical conductivity of the a-IZTO anode films rather than the optical transparency at thinner a-IZTO films. On the other hand, despite the much lower $R_{series}$ comes from thicker anode films, the dominant factor affecting the $J_{sc}$ became average optical transmittance of a-IZTO electrodes as well as power conversion efficiency (PCE) in same device configuration due to the thick anode films had as sufficiently low $R_{sheet}$ to extract the hole carrier from the active material.

• Journal of Powder Materials
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• 제28권6호
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• pp.455-461
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• 2021

In this study, multilayered SnO nanoparticles are prepared using oleylamine as a surfactant at 165℃. The physical and chemical properties of the multilayered SnO nanoparticles are determined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Interestingly, when the multilayered SnO nanoparticles are heated at 400℃ under argon for 2 h, they become more efficient anode materials, maintaining their morphology. Heat treatment of the multilayered SnO nanoparticles results in enhanced discharge capacities of up to 584 mAh/g in 70 cycles and cycle stability. These materials exhibit better coulombic efficiencies. Therefore, we believe that the heat treatment of multilayered SnO nanoparticles is a suitable approach to enable their application as anode materials for lithium-ion batteries.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• 제21권1호
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• pp.9-22
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• 2023

Spin-off pyroprocessing technology and inert anode materials to replace the conventional carbon-based smelting process for critical materials were introduced. Efforts to select inert anode materials through numerical analysis and selected experimental results were devised for the high-throughput reduction of oxide feedstocks. The electrochemical properties of the inert anode material were evaluated, and stable electrolysis behavior and CaCu generation were observed during molten salt recycling. Thereafter, CuTi was prepared by reacting rutile (TiO₂) with CaCu in a Ti crucible. The formation of CuTi was confirmed when the concentration of CaO in the molten salt was controlled at 7.5mol%. A laboratory-scale electrorefining study was conducted using CuTi(Zr, Hf) alloys as the anodes, with a Ti electrodeposit conforming to the ASTM B299 standard recovered using a pilot-scale electrorefining device.

• Journal of the Korean Chemical Society
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• 제46권6호
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• pp.528-534
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• 2002

We have studied to find the optimum electrolyte that satisfied high ionic conductivity, large elec-trochemical window, etc in Li-ion battery. And also studied were the effect of a passive film on carbon anode surface,which is formed by solvent decomposition during the initial charge process. Electrochemical properties of the passive film formed on carbon anode surface investigated and explained as the volumetric ratio of the mixed solvents. The results of scanning electron microscopy, chronopotentiometry, cyclic voltammetry, impedance spectroscopy revealed that the electrochemical properties of the passive film were varied with the ionic conductivity of the electrolyte including the mixed solvents.

• Journal of the Korean Ceramic Society
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• 제48권6호
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• pp.520-524
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• 2011

The properties of manufactured SOFC unit cell using decalcomania method were investigated. The decalcomania method that used in ceramics, dish, vessel and etc. was the very simple process. The SOFC unit cell manufacturer using decalcomania method is very simple process. Especially, the decalcomania method was the most suitable manufacturing method for the segmented type SOFC. The cathode, prevent diffusion layer (PDL), anode functional layer (AFL) and electrolyte were manufactured using decalcomania method on porous anode support. The sintered electrolyte at 1450$^{\circ}C$ for 2 h using decalcomania method was very dense, and the thickness was about 10 ${\mu}m$. The cathode, the PDL and the AFL were manufactured using decalcomania method and was sintered at 1250$^{\circ}C$ for 2 h, and the sintered electrodes were the porous. As a result, with humidified hydrogen used as fuel, the cell with an 15 ${\mu}m$-thick AFL exhibited maximum power densities of 0.246, 0.364, 0.504W/$cm^2$ at 700, 750, 800$^{\circ}C$, respectively.

• Journal of the Korean Ceramic Society
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• 제43권12호
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• pp.823-828
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• 2006

One of the main issues of Solid Oxide Fuel Cells (SOFCs) is to reduce the operating temperature to $750^{\circ}C$ or less. It has advantages of improving the life of component parts and the long-term stability of a system, so the production cost could be decreased. In order to achieve that, the ohmic and polarization loss of a single cell should be minimized first. This paper presents.to fabricate anode-supported single cells with controlling microstructure as a function of particle size and volume of graphite and NiO-YSZ weight ratio. By means of optimizing the manufactural condition through microstructure analysis and performance evaluation, the single cell which had NiO-YSZ=6:4, graphite volume of 24% and graphite size of $75{\mu}m$ as the anode composition showed a distinguished power density of $510mW/cm^2$ at $650^{\circ}C$ and $810mW/cm^2$ at $700^{\circ}C$, respectively.