• Journal of the Korean institute of surface engineering
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• v.48 no.2
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• pp.68-72
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• 2015

The corrosion behavior of metals and alloys for the safety of offshore structures in seawater was investigated for the application of sacrificial anodes. The experiments were focused on the polarization behaviors and the surface morphology of each metal after experiments. Pure Zn, pure Al (Al1050), Al alloys (Al5052, Al6061), Mg alloys (AZ31, AZ91D) and steel (SCM440) were assessed in 3.5% sodium chloride solution by means of potentiodynamic polarization to verify the galvanic corrosion potential ($E_{couple}$). Potentiostat plots were plotted to compare the surface and corrosion current density ($i_{couple}$) of metals as sacrificial anodes in seawater to protect steel alloy as a cathode. Al alloys showed the best performance as a sacrificial anode, on the other hand, Mg alloys showed overprotection behavior. The surface morphologies of sacrificial anodes were observed by FESEM and compared.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.188-190
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• 2007

The MEA with the catalyst layer containing PtRu black and 60 wt. %Pt/C as their anode and cathode catalysts. For find to effect of carbon support, the MEA with platinum black for cathode catalyst was fabricated. The performance of the MEA with the catalyst layer containing (PtRu black:60 wt.% Pt/C) as their anode and cathode catalyst has shown competitively higher value than the performance of the MEA with the catalyst layer containing (PtRu black:Pt black) as their anode and cathode catalyst.

• Environmental Engineering Research
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• v.19 no.4
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• pp.363-367
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• 2014

One chambered sediment microbial fuel cell (SMFC) was equipped with Fe, brass (Cu/Zn), Fe/Zn, Cu, Cu/carbon cloth and graphite felt anode. Graphite felt was used as common cathode. The SMFC was membrane-less and mediator-less as well. Order of anodic performance on the basis of power density was Fe/Zn ($6.90Wm^{-2}$) > Fe ($6.03Wm^{-2}$) > Cu/carbon cloth ($2.13Wm^{-2}$) > Cu ($1.13Wm^{-2}$) > brass ($Cu/Zn=0.24Wm^{-2}$) > graphite felt ($0.10Wm^{-2}$). Fe/Zn composite anode have twisted 6.73% more power than Fe alone, Cu/carbon cloth boosted power production by 65%, and brass (Cu/Zn) produced 65% less power than Cu alone. Graphite felt have shown the lowest electricity generation because of its poor galvanic potential. The estuarine sediment served as supplier of oxidants or electron producing microbial flora, which evoked electrons via a complicated direct microbial electron transfer mechanism or making biofilm, respectively. Oxidation reduction was kept to be stationary over time except at the very initial period (mostly for sediment positioning) at anodes. Based on these findings, cost effective and efficient anodic material can be suggested for better SMFC configurations and stimulate towards practical value and application.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2144-2148
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• 2008

Kerosene-driven solid oxide fuel cell (SOFC) system with reformer, desulfurizer and after-burner was mainly developed for this study. Originally the system was developed for 1kW class SOFC system for residential power generation (RPG) application. As a preliminary study of 1kW class SOFC system operation, a short stack was applied to the system. The short stack consists of 7 cells of $10cm{\times}10cm$ area and was operated at $720^{\circ}C$. The effect of anode inlet gas composition to stack performance was investigated. Firstly, I-V characteristics of SOFC with different fuel of kerosene and hydrogen were studied. Secondly $CH_4$ internal reforming was performed at various anode inlet gas compositions of $H_2$, $CH_4$ and $H_2O$. Through these experiments the effects of each anode inlet gas component to stack performance were analyzed and the significant operating parameters were iscussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.371-374
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• 2000

The electrochemical properties of LiM $n_2$ $O_4$as a cathode and an anode for the lithium secondary battery were evaluated. When LiM $n_2$ $O_4$ material was used as the cathode with the current collector of aluminum, the 1st specific capacity and the 1st Ah efficiency in LiM $n_2$ $O_4$/lithium cell were 123 mAh/g and 91.7%, respectively The anodic properties of LiM $n_2$ $O_4$ material was also evaluated in the LiM $n_2$ $O_4$/1ithium cell with the current collector of copper. It showed that the LiM $n_2$ $O_4$ was useful as the anode for the lithium secondary battery. During the 1st discharge, a potential plateau was observed at the potential of 0.3 $V_{Li}$ Li+/. The 1st specific charge capacity and the 1st specific discharge capacity were 790 mAh/s and 362 mAh/g, respectively. Therefore, the 1st Ah efficiency was 46%. The discharge capacity was gradually faded with the charge-discharge cycling to about 50th cycles. Thereafter, the discharge capacity was stabilized to about 110 mAh/g.

• Journal of Powder Materials
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• v.28 no.6
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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 Electrochemical Science and Technology
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• v.13 no.1
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• pp.90-99
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• 2022

Owing to the rising concern of global warming, lithium-ion batteries have gained immense attention over the past few years for the development of highly efficient electrochemical energy conversion and storage systems. In this study, alpha-phase VOPO₄·2H₂O with nanosheet morphology was prepared via a facile hydrothermal method for application in high-performance lithium-ion batteries. The X-ray diffraction and scanning electron microscopy (SEM) analyses indicated that the obtained sample had an alpha-2 (αII) phase, and the nanosheet morphology of the sample was confirmed using SEM. The lithium-ion battery with VOPO₄·2H₂O as the anode exhibited excellent long-term cycle life and a high capacity of 256.7 mAh g^-1 at room temperature. Prelithiation effectively improved the specific capacity of pristine VOPO₄·2H₂O. The underlying electrochemical mechanisms were investigated by carrying out AC impedance, rate capability, and other instrumental analyses.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.4
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• pp.241-247
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• 2010

Corrosion of steel embedded in concrete is one of the foremost factors that affect the durability of concrete structures in marine environments. This paper presents an application technique of anode-ladder-system to evaluate corrosion behaviours of marine concrete structure. In order to investigate the behaviours quantitatively, the measurement of potential and current was performed on the concrete elements subjected to the penetration and diffusion of chloride ions. The main variable was the heights from seawater level; namely 3.7, 6.0 and 8.2 m. As a result of the monitoring, it was found that the corrosion characteristics differently behaved with the increasing height. Additionally, through migration test, the relationship between compressive strength of concrete and diffusivity of chloride ions was observed. It is suggested, ultimately, that in order to reduce or mitigate steel corrosion, both appropriate concrete cover depth and high-quality of concrete in early ages should be done.

• Journal of Electrochemical Science and Technology
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• v.5 no.2
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• pp.37-44
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• 2014

The $Li-O_2$ battery has been attracting much attention recently, due to its very high theoretical capacity compared with Li-ion chemistries. Nevertheless, several studies within the last few years revealed that Li-ion derived electrolytes based on alkyl carbonate solvents, which have been commonly used in the last 27 years, are irreversibly consumed at the $O_2$ electrode. Accordingly, more stable electrolytes are required capable to operate with both the Li metal anode and the $O_2$ cathode. Thus, due to their favorable properties such as non volatility, chemical inertia, and favorable behavior toward the Li metal electrode, ionic liquid-based electrolytes have gathered increasing attention from the scientific community for its application in $Li-O_2$ batteries. However, the scale-up of Li-$O_2$ technology to real application requires solving the mass transport limitation, especially for supplying oxygen to the cathode. Hence, the 'LABOHR' project proposes the introduction of a flooded cathode configuration and the circulation of the electrolyte, which is then used as an oxygen carrier from an external $O_2$ harvesting device to the cathode for freeing the system from diffusion limitation.

• Journal of IKEEE
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• v.25 no.1
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• pp.168-173
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• 2021

In this paper, we propose a new structure of ESD protection device that achieves improved electrical characteristics through structural change of LVTSCR, which is a general ESD protection device. In addition, it applies N-Stack technology for optimized design in the ESD Design Window according to the required voltage application. The N-Well area additionally inserted in the existing LVTSCR structure provides an additional ESD discharge path by electrically connecting to the anode, which improves on-resistance and temperature characteristics. In addition, the short trigger path has a lower trigger voltage than the existing LVTSCR, so it has excellent snapback characteristics. In addition, Synopsys' T-CAD Simulator was used to verify the electrical characteristics of the proposed ESD protection device.