• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.31.1-31.1
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• 2011

$Li_4Ti_5O_{12}$ is emerging as a promising material with its good structure stability and little volume change during the electrochemical reaction. However, its electrochemical performance is significantly limited by low electronic or ionic conductivity. In addition, high tap density is needed forim proving its volumetric energy density and commercialization. To enhance these properties, the spherical-like $Li_4Ti_5O_{12}$ particles were synthesized and carried out doping with yttrium. Prepared Y-doped $Li_4Ti_5O_{12}$ as a anode material showed great capacity retention rate of 92% (5C/0.2C), compared with no dope done. Consequently, it was found that Y doping into $Li_4Ti_5O_{12}$ matrix reduces the polarization and resistance on SEI layer during the electrochemical reaction.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1686-1687
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• 2011

A microfabricated chip with in-channel electrochemical cell using interdigitated gold electrode was fabricated for sensitive electrochemical analysis. The gold electrodes were fabricated on glass wafer using thermal evaporator and were covered using PDMS mold containing microchannel for analyte and electrolyte. The active area of each electrode was $250\;{\mu}m{\times}200\;{\mu}m$ with a gap of 200 ${\mu}m$ between the electrodes. Microelectrodes results in maximum amplification of signal, since the signal enhancement effect due to cycling of the reduced and oxidized species strongly depends on the inter electrode distance. Analytes such as methylene blue and guanosine were characterized using the fabricated electrodes and their electrochemical characteristics were compared with conventional bulk electrodes. The device so developed shall find use as disposable electrochemical cell for rapid and sensitive analysis of electroactive species.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.126-129
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• 2000

This paper describes on the fabrication of a SOI substrate by SDB technology and electrochemical etch-stop. The surface of the thinned SDB SOI substrate is more uniform than that of grinding or polishing by mechanical method, and this process was found to be very accurate method for SOI thickness control. During electrochemical etch-stop, leakage current versus voltage curves were measured for analysis of the open current potential (OCP) point, the passivation potential (PP) point and anodic passivation potential. The surface roughness and the controlled thickness selectivity of the fabricated a SDB SOI substrate were evaluated by using AFM and SEM, respectively.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.4
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• pp.331-335
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• 2019

In this study we investigate catalytic activity and selectivity of mixture of Ag and ketjenblack according to their ratios by product analysis and electrochemical experiments, such as cyclic voltammetry, linear sweep voltammetry and chronoamperometry. We reveal that catalytic activity toward CO₂ reduction to CO is improved by simple mixing Ag nanoparticle and ketjenblack because addition of ketjenblack suppresses aggregation of Ag nanoparticles and brings increase in electrochemical active surface area. However, excess amount of ketjenblack rather inhibit the CO₂ reduction to CO. These observations provide clues to develop highly active Ag catalyst or electrode toward electrochemical reduction of CO₂.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.159-160
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• 2017

본 논문에서는 리튬배터리의 전기화학적 분석법으로 전기 화학적 전압 분광법(electrochemical voltage spectroscopy;EVS)을 사용하였다. 전기화학적 활성상태의 밀도를 직접 측정하는 기법으로 정전압(potentiostatic) 제어를 기반으로 한다. EVS 테스트에서 양전극의 전압은 각 단계가 전기화학적 평행상태에 도달할 때 까지 유지되며 이 방법은 배터리의 전기화학적 산화 환원 전위의 미세한 차이에 기초하여 활성 물질의 상태에 대한 정확한 정보를 얻을 수 있다.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1724-1729
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• 2007

Smaller size and higher integration of electronic systems make narrower interconnect pitch not only in chip-level but also in package-level. Moreover electronic systems are required to operate in harsher conditions, that is, higher current / voltage, elevated temperature/humidity, and complex chemical contaminants. Under these severe circumstances, electronic components respond to applied voltages by electrochemically ionization of metals and conducting filament forms between anode and cathode across a nonmetallic medium. This phenomenon is called as the Electrochemical migration

• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.111-116
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• 2006

Micro machining of tungsten carbide by electrochemical machining was studied. In ECM, machining conditions and electrolyte should be chosen carefully according to the property of workpiece materials. In this paper, sulfuric acid and nitric acid were used for tungsten carbide machining and machining characteristics were investigated according to machining conditions such as electrolyte, workpiece potential and applied pulse voltage. By using mixture of sulfuric acid and nitric acid, micro structures with sharp edge and good surface quality were obtained. Micro electrochemical turning was also introduced to fabricate micro shafts.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.159.2-159.2
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• 2011

In this study, we prepared the activated graphite nanofibers (A-GNFs) via chemical activation with KOH reagent. The effect of A-GNFs on the surface and textural properties of Ni-loaded graphite nanofibers (Ni/GNFs) was investigated by X-ray diffraction (XRD), transmission electron microscope (TEM), and Brunauer-Emmett-Teller (BET). The textural properties of samples were investigated by $N_2$/77K adsorption isotherms. The electrochemical performances were investigated by cyclic voltammetry. As a results, the electrochemical performances of Ni/GNFs were improved with usage of A-GNFs. This could be interpreted by the high specific surface area and large total pore volume of the A-GNFs.

• Journal of Powder Materials
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• v.18 no.1
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• pp.49-55
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• 2011

Ni nanowires were fabricated using anodic aluminum oxide (AAO) membrane as a template by electrochemical deposition. The nanowires were formed within the walls of AAO template with 200 nm in pore diameter. After researching proper voltage and temperature for electrochemical deposition, the length of Ni nanowires was controlled by deposition time and the supply of electrolyte. The morphology and microstructure of Ni nanowires were investigated by field emission scanning electron microscope (FE-SE), X-ray diffraction (XRD) and transmission electron microscope (TEM).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.295-298
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• 1998

We have investigated ionic conductivity and electrochemical stability of the electrolytes containing organic solvent. Ion conductivities were measured between 10 and 80$^{\circ}C$, and electrochemical stabilities were determined by cyclic voltammetry on glassy carbon, platinum and aluminum electrodes. Ionic conductivity of electrolyte(EC:DEC=1:1) with IM LiPF$\_$6/ shows better than that of the other electrolytes having Li salts. The IM LiBF$_4$-PC electrolyte exhibits good electrochemical stability. IM LiPF$\_$6/ (EC:DEC=1:1) and IM LiPF$\_$6/ (EC:DMC=1:1) electrolytes are used for the high capacity of battery system.