• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.277-278
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• 2008

Orthorhombic $LiMnO_2$(o-$LiMnO_2$) has attracted public attentions as a cathode materials of Lithium ion battery because it has low cost and high theoretical discharge capacity of 285mAh $g^{-1}$. In our study, o-$LiMnO_2$ is synthesized by quenching method. To verify their phase structure, X-ray diffraction is accomplished. Test cells are assembled to check electrochemical characteristics using acquired o-$LiMnO_2$ cathode and carbon anode. Charge/Discharge cycling was carried out for 50cycles. And impedance was measured at 1, 2, 5, 10, 30, 50cycle. During cycle test, the max discharge capacity was recorded 139mAh $g^{-1}$ at 10cycle.

• 한국공작기계학회논문집
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• 제14권1호
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• pp.44-51
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• 2005

Material degradation is a multibillion-dollar problem which affects all the industries amongst others. The last decades have seen the development of newer and more effective techniques such as Focused-ion beam(FIB), Transmission electron microscopy(TEM), Secondary-ion mass spectroscopy(SIMS), auger electron spectroscopy(AES), X-ray Photoelectron spectroscopy(XPS) , Electrochemical impedance spectroscopy(EIS), Photo- stimulated luminescence spectroscopy(PSLS), etc. to study various forms of material degradation. These techniques are now used routinely to obtain information on the chemical state, depth profiling, composition, stress state, etc. to understand the degradation behavior. This paper describes the use of these techniques specifically applied to materials degradation and failure analysis.

• 한국소음진동공학회논문집
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• 제16권7호
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• pp.762-768
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• 2006

To address the need for new intelligent sensing of systems, this study presents a novel strain sensor based on piezoresistivity of carbon nanotube (CNT) and its nanocomposites. Fabrication and characterization of the carbon nanocomposite material are discussed and an electrical model of the CNT strain sensor was derived based on electrochemical impedance spectroscopy analysis and strain testing. The dynamic response of the sensor on a vibrating beam was simulated using numerical analysis and it was compared with experimental test. The simulation showed good agreement with the strain response of the actual sensor.

• Corrosion Science and Technology
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• 제11권5호
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• pp.165-172
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• 2012

The corrosion resistance of epoxy-coated carbon steel was evaluated. The carbon steel surface was subjected to different treatment methods such as steel grit blasting with different size, steel shot ball blasting and power tool treatment. To study the effect of the treatments, the topology of the treated surface was observed by optical 3D microscopy and a pull-off adhesion test was conducted. The corrosion resistance of the epoxy-coated carbon steel was further examined by electrochemical impedance spectroscopy (EIS) combined with hygrothermal cyclic testing. The results of EIS indicated that the epoxy-coated carbon steel treated with steel grit blasting showed an improved corrosion resistance compared to untreated epoxy-coated surfaces or surfaces subjected to shot ball blasting and power tool treatments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.160-163
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• 2005

Several sensors are involved in the cor개sion monitoring of concrete structures. This paper deals with the monitoring of concrete structures by embeddable reference sensors. $MnO_2$, MMO and graphite reference sensors are fabricated in the laboratory as suitable as embeddable type into the concrete structures. Sensors are embedded into the mortars and the performance was studied in the absence and presence of chloride ions. The electrochemical stability of the sensors was carried out for the exposure period of one year. Polarisation behaviour and impedance of the sensors in mortar was carried out in three aqueous solutions namely distilled water, 3% NaCl and natural sea water.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1407-1408
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• 1996

The development of MCFC is going to the second stage of development and recent studies have been focusing on long-term durability of cell component. Systematic investigation on corrosion behavior of Fe-based alloys has been done in (62+38) mol % (Li+K) $CO_3$ melt at 923K by using steady-state polarization and electrochemical impedance spectroscopy method. It was found that the corrosion current t of these Fe-based alloys decreased with increasing Cr, Al content.

• Journal of Advanced Marine Engineering and Technology
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• 제36권3호
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• pp.341-350
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• 2012

In this paper we observe the protective coatings carbon for steel, aluminium and titanium alloys were obtained by plasma electrolytic oxidation (PEO) under unipolar and bipolar conditions. The anticorrosion properties and the thermal stability of the surface layers were studied by electrochemical impedance spectroscopy and potentiodynamic polarization. It was found that the application of the bipolar PEO mode enables one to synthesize the surface layers that possess enhanced anticorrosion and mechanical properties. results of research of antiscale PEO - coatings for marine power equipment are presented. The combined method of prevention of corrosion and scale formation was tested at the industrial plants of Russian Shipyard "Zvezda".

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.105-106
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• 2017

The metal spray method, one of the surface anti-corrosion methods to prevent the corrosion of the steel material, does little effects on the material, while it can be used on a wider surface. However, metal spraying is used only in a limited environment, and research on the case of using with concrete is lacking. The purpose of this study was to observe the corrosion behavior of steels with metal spray coatings in concrete using electrochemical methods And to evaluate the performance of the method according to the type of metal used in the metal spray. As a result, the Al metal spray coating showed the best performance, because Aluminum is oxidized in the cement mortar and forms alumina oxide film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 추계학술대회 논문집
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• pp.101-105
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• 1994

A/F sensor with a sensing and a pumping element, which is made of YSZ(yttria stabilized zirconia) sheets, can be used for the combustion control of lean burn engine. A/F sensor can detect the oxygen partial pressure in more wide range than the other oxygen sensors, such as the limiting current type oxygen sensor and λ-sensor. However this sensor has the disadvantage that the characteristics has been degraded rapidly due to the physical or electrochemical reasons. The blackening phenomenon is known as one of the degradations caused by high voltage biased for oxygen pumping. In this paper, we have studied to analyze the blackening phenomenon by comparing two characteristics between before and after blackening in impedance spectroscopy, and discussed the blackening mechanism.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.88.2-88.2
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• 2011

Proton exchange memb rane fuel cell has been considered one of the next generation power source for electric vehicles due to high power density and low emissions. $TiO_2$/Nafion composite was prepared by the in-situ sol-gel method. The electrochemical characteristics of the $TiO_2$-Nafion composite membrane were evaluated by current-voltage and impedance of the membrane eletrode assembly in a single Proton exchange membrane fuel cell (PEMFC).