• Journal of the Korean institute of surface engineering
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• v.28 no.1
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• pp.46-54
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• 1995

An electrochromic(EC) cell was constructed using $WO_3$ as a electrochromic material and NiO as a counter electrode, deposited onto ITO-coated glass by the implementation of electron beam evaporation. The electrolytic media were both lithium and proton conducting polymers such as poly-acrylonitrile(PAN)-$LiClO_4$, poly-ethylene oxide(PEO)-$LiClO_4$, poly-vinyl butyral(PVB)-LiCl and PVB-H$_3$$PO_4$. Potentiodynamic cycling of the cells using PAN-$LiClO_4$, or PVB-$H_3$$PO_4$ electrolyte yielded a transmission variation of more than 40% at the wavelength of 632.8 nm within less than 10 sec response time at room temperature. These results indicate that these electrolytes, transparent in gel type, are premising for the application in large area electrochromic windows.

• Journal of the Korean Electrochemical Society
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• v.6 no.3
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• pp.174-177
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• 2003

Electric double-layer capacitors based on charge storage at the interface between a high surface area activated carbon electrode and an electrolyte solution are characterized by their long cycle-life and high power density in comparison with batteries. However, energy density of electric double-layer capacitors obtained at present is about 6 Wh/kg at a power density of 500W/kg which is smaller as compared with that of batteries and limits the wide spread use of the capacitors. Therefore, a new capacitor that shows larger energy density than that of electric double-layer capacitors is proposed. The new capacitor is the hybrid capacitor consisting of activated carbon cathode, carbonaceous anode and an organic electrolyte. Maximum voltage applicable to the cell is over 4.2V that is larger than that of the electric double-layer capacitor. As a result, discharged energy density on the basis of stacked volume of electrode, current collector and separator is more than 18Wh/l at a power density of 500W/l.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.105-106
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• 2008

Nanotube morphology change of Ti-Ta-Zr alloy as Zr content increase has been researched using various experimental methods. Ti-Ta-Zr(3, 7 and 15 wt%) alloys were prepared by arc melting and nano-structure controlled for 24 hr at $1000^{\circ}C$ in argon atmosphere. Formation of oxide nanotubes are conducted by anodizing a Ti-Ta-Zr alloy in $H_3PO_4$ electrolytes with small amounts of fluoride ions at room temperature. Electrochemical experiments were carried out with conventional three-electrode configuration with a platinum counter electrode and a saturated calomel reference electrode. The samples were embedded with epoxy resin, leaving a square surface area of $10mm^2$ exposed to the anodizing electrolyte, 1.0M $H_3PO_4$ containing 0.8wt% NaF.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.33-33
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• 2010

Recently, a self-organizing process that occurs during the anodization of aluminum in acidic electrolytes has attracted a vast amount of research attentions, coupled with the ever-increasing demand for the development of effective, inexpensive and technologically simple methods for the synthesis of low-dimensional nanostructures over a macroscopic area overcoming many of the drawbacks of conventional lithographic techniques. In this presentation, recent progress in the fabrication of ordered nanoporous anodic aluminum oxide (AAO), including conventional anodization techniques, newly developed pulse anodization, hard anodization processes, and generic approaches to three-dimensional pore structures with periodically modulated diameters. Discussion will also cover the applications of AAO for the development of structurally well-defined extended arrays of low-dimensional nanostructures, such as nanodots, nanotubes, and nanowires, which could be model systems in investigating a diverse range of research problems in chemistry and physics and also be starting materials in realizing advanced electronic devices.

• 산업보건소식
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• no.47
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• pp.4-14
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• 1987

The authors investigated estimated amounts of salt intake of workers in manufacturing industries who consisted of 1,506 males in 6 manufacturing fields and 476 females in 3 fields in Pusan area using filter paper method which was developed recently. The obtained results were as follows; 1. Mean excretion amounts of urinary electrolytes were Na 200.7 mEq/l, K 44.2 mEq/l and Cr 1.12g/l in male and Na 190.2 mEq/l, K 44.0 mEq/l and Cr 1.10g/1 in female. 2. Mean daily salt intake amounts were 19.4g in male and l5.3g in female. 3. By the fields of manufacturing industries in male, workers in metal product field had the highest salt intake as 20.0g, and the following were workers in food and tobacco field as 19.7g, workers in textile, wearing apparel and leather field as 19.6g in order. 4. In female, workers in textile, wearing apparel and leather field had the highest salt intake as l5.7g and the next were workers in chemical, coal and rubber products field as l5.0g and workers in fabricated metal products, machinery and equipments as l4.3g, respectively.

• Journal of the Korean Chemical Society
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• v.60 no.5
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• pp.299-309
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• 2016

In this study, the physicochemical and electrochemical properties of carbon nanomaterials and synthesized nano-carbon/Si composites were studied. The nano-carbon/Si composites were ball-milled to a nano size and coated with pyrolytic carbon using Chemical Vapor Deposition (CVD). They were then finely mixed with respective nano-carbon materials. The physicochemical properties of samples were analyzed using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Raman spectroscopy, X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and surface area analyzer. The electrochemical characteristics were investigated using the galvanostatic charge-discharge and cyclic voltammetry (CV) measurements. Three-electrode cells were fabricated using the carbon nanomaterials and nano-carbon/Si composites as anode materials and LiPF₆ and LiClO₄ as electrolytes of Li secondary batteries. Reversibility using LiClO₄ as an electrolyte was superior to that of LiPF₆ as the electrolyte. The initial discharge capacities of nano-carbon/Si composites were increased compared to the initial discharge capacities of nano-carbon materials.

• Journal of Electrochemical Science and Technology
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• v.8 no.3
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• pp.236-243
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• 2017

A fixed-bed zinc/nickel redox flow battery (RFB) is designed and developed. The proposed cell has been established in the form of a fixed bed RFB. The zinc electrode is immersed in an aqueous NaOH solution (anolyte solution) and the nickel electrode is immersed in the catholyte solution which is a mixture of potassium ferrocyanide, potassium ferricyanide and sodium hydroxide as the supporting electrolyte. In the present work, the electrode area has been maximized to $1500cm^2$ to enforce an increase in the energy efficiency up to 77.02% at a current density $0.06mA/cm^2$ using a flow rate $35cm^3/s$, a concentration of the anolyte solution is $1.5mol\;L^{-1}$ NaOH and the catholyte solution is $1.5mol\;L^{-1}$ NaOH as a supporting electrolyte mixed with $0.2mol\;L^{-1}$ equimolar of potassium ferrocyanide and potassium ferricyanide. The outlined results from this study are described on the basis of battery performance with respect to the current density, velocity in different electrolytes conditions, energy efficiency, voltage efficiency and power of the battery.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.309-311
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• 2007

Supramolecules containing double hydrogen bonding sites at their both chain ends were self-polymerized to become solid state polymer and were utilized to improve the efficiency of solid state DSSCs. Hydrogen bonding sites were attached at the chain ends of PEG of Mw=2000, such as pyrimethamine and glutaric acid. The solar cell with the solid state supramolecular polymer electrolyte resulted in the overall energy conversion efficiency of 4.63 % with a short circuit current density $(J_{sc})$ of 10.41 $mAcm^{-2}$, an open circuit voltage $V_{oc}$, of 0.71 V and a fill factor (FF) of 0.62 at one sun condition ([oligomer]:[1-methyl-3-propyl imidazolium iodide (MPII)]:$[I_2]$ = 20 : 1 : 0.19, active area = 0.16 $cm^2$, $TiO_2$ layer thickness = 10 ${\mu}m$). The ionic conductivity of the sol id state electrolyte was $5.11{\times}10^{-4}$ (S/cm). The cell performance was characterized by electrochemical impedance spectroscopy and ionic conductivity.

• Journal of the Korean Ceramic Society
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• v.48 no.2
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• pp.200-204
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• 2011

Increase of surface area and decrease of band gap in $TiO_2$ semiconductors are significant to improve the efficiency of water splitting by photoelectrolysis. In this study $TiO_2$ nanotube arrays with ~7 um length and ~100 nm diameter were fabricated by an anodizing technique of titanium foils using DMSO (dimethyl sulfoxide)-based electrolytes. Then to control the band gap of the $TiO_2$ arrays, they were annealed at $550^{\circ}C$ for up to 180 min in $NH_3$ gas ambient. The samples annealed in $NH_3$ gas for 30 min and 60 min showed superior photo-conversion efficiency for water splitting under white and visible light. A $TiO_2$ nanotube annealed in $NH_3$ gas ambient for a period longer than 120 min showed 1 order higher leakage current. It is believed that the decrease of band gap and increase of conductivity in $TiO_2$ nanotube arrays due to $NH_3$ gas treatments result in the superior water-splitting performance.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.350-354
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• 2009

In this work, polymer - inorganic composites have prepared using polymer such as polyethylene glycol (PEG)/poly (methyl methacrylate, PMMA) and inorganic nanofillers materials such as TiO2 nanotubes (TiNTs)/carbon nanotubes (CNTs). The extensive structural, morphological and ionic properties revealed that the high surface area and tubular feature of nanofillers improved the interaction and cross-linking to polymer matrix which is significantly enhanced the ionic conductivity and electrical properties of composite electrolytes. Comparably high conversion efficiency ~4.5% has been observed by using the newly prepared PEG-TiNTs composite solid electrolyte as compared with PMMA-CNTs electrolyte based DSSCs (~3%). The detailed comparative properties would be discussed in term of their structural, morphology, ionic and photovoltaic properties.