• Polymer(Korea)
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• v.29 no.2
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• pp.216-220
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• 2005

A new type of polymer gel electrolyte was prepared from poly(ethylene glycol) diacrylate(PEGDA) and 1-butyl-3-methylimidazolium bis((trifluorornethyl) sulfonyl) amide$(BuMeIm^+Tf_2N^-)$ ionic liquid. The effect of the ionic liquid on ionic conductivity of the gel polymer electrolyte was investigated. It was observed that the gel polymer electrolyte having the ionic liquid exhibited higher ionic conductivity $(ca.\;10^{-3}S/cm)$ as well as electrochemical stability than that using organic solvent.

• Journal of the Korean Electrochemical Society
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• v.4 no.2
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• pp.41-46
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• 2001

The effect of organic additives such as PEG ind MPS on throwing power have been studied in the fabrication of porous reticular metal by electrodeposition using the mixture of cupric sulfate and sulfuric acid as electrolyte. Both the polarization test and the electrodeposition on the stacked electrodes, mean pore diameter of which was $250{\mu}m$, were performed to illustrate the behavior of throwing power quantitatively. As far as PEG was concerned, it lowered throwing power of electrodeposition on the porous electrode used in this work while the addition of MPS up to 500 ppm in electrolyte enhanced throwing power monotonously. When both MPS and PEG were added in electrolyte, the effect of MPS on throwing power was superior to that of PEG. However, the excess addition of MPS was found to cause the defect in mechanical strength of deposit layer. From the result of SEM observation, it could be concluded that less than 50 ppm of MPS in electrolyte was appropriate to avoid the breakage of deposit layer.

• Journal of the Korean Electrochemical Society
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• v.15 no.1
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• pp.1-11
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• 2012

Recently lithium ion secondary batteries (LIB) have rapidly developed because of their advantages such as high energy densities and capacities. Among them, an electrical vehicle which is the one of the environmental-friendly transportation facilities has been received a great attention, but, it is needed to overcome several obstacles of the LIB performances. LIB is practically adapted to Hybrid Electric Vehicle (HEV), but the issues for high capacities, long life time and safety should be solved. Moreover, LIBs still have some possibilities of explosion in the case of overheating of the used organic electrolyte and overcharging of the cell. Hence, it is urgently needed to replace the liquid electrolytes into the solid electrolytes due to the safety issues. Therefore, in this review, we summarized and discussed the research trends of the solid electrolyte to solve the concerns of safety and capacity of LIBs and published patents and articles.

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.783-786
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• 2009

Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and ion chromatography(IC) were employed to analyze the thermal behavior of $Li_xCoO_2$ cathode material of lithium ion battery. The mass loss peaks appearing between 60 and 125 ${^{\circ}C}$ in TGA and the exothermic peaks with 4.9 and 7.0 J/g in DSC around 75 and 85 ${^{\circ}C}$ for the $Li_xCoO_2$ cathodes of 4.20 and 4.35 V cells are explained based on disruption of solid electrolyte interphase (SEI) film. Low temperature induced HF formation through weak interaction between organic electrolyte and LiF is supposed to cause carbonate film disruption reaction, $Li_2CO_3\;+\;2HF{\rightarrow}\;2LiF\;+\;CO_2\;+\;H_2O$. The different spectral DSC/TGA pattern for the cathode of 4.5 V cell has also been explained. Presence of ionic carbonate in the cathode has been identified by ion chromatography and LiF reported by early researchers has been used for explaining the film SEI disruption process. The absence of mass loss peak for the cathode washed with dimethyl carbonate (DMC) implies ionic nature of the film. The thermal behavior above 150 ${^{\circ}C}$ has also been analyzed and presented.

• Membrane Journal
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• v.29 no.2
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• pp.80-87
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• 2019

Dye-sensitized solar cells (DSSCs) have attracted great attention as sustainable energy devices. The efficiency and long-term stability of DSSCs are greatly influenced by electrode materials and electrolytes. In this review, we focused on the electrolytes of DSSCs. Polymer electrolyte membranes have been proposed as an alternative to conventional liquid electrolytes in DSSCs. Conventional liquid electrolytes can exhibit a high efficiency, but due to some problems such as poor long-term stability of device and leakage of liquid, much interest in polymer electrolyte membranes continues to rise and the papers on polymer electrolytes membranes have been extensively reported recently. This review covers the concept and development of polymer electrolyte membranes for DSSCs, and discusses the efficiency and electrochemical properties of DSSCs, highlighting the modification of polymer matrix, the introduction of additives such as organic-inorganic plasticizers and ionic liquids.

• Journal of the Korean GEO-environmental Society
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• v.18 no.4
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• pp.23-29
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• 2017

As the Enforcement Ordinance of Environmental Policy Act was revised in 2013, Total Organic Carbon (TOC) was added as an indicative parameter for organic matter in Water and Aquatic Ecosystem Environmental Criteria. Under these imminent circumstances, a regulatory standard is needed to achieve the proposed TOC limitation control water quality from the STP (Sewage Treatment Plant). In this study, a electrolysis utilizing the electrochemical reaction was investigated in lab-scale experiments for the treatment of TOC in sewage effluent. TOC reduction by a electrolysis was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of electrode space ($x_1$), current density ($x_2$) and electrolyte concentration ($x_3$) on the dependent variables removal efficiency of TOC (y). The optimal conditions for electrolysis were determined: electrode space, current density and electrolyte concentration were 50 mm, $10.3mA/cm^2$ and 0.1M, respectively. Statistical results showed the order of significance of the independent variables to be electrode space > current density > electrolyte concentration.

• Journal of Electrochemical Science and Technology
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• v.6 no.1
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• pp.16-25
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• 2015

Transition metal oxide nanocrystalline materials are playing major role in energy storage application in this scenario. Nickel oxide is one of the best antiferromagnetic materials which is used as electrodes in energy storage devices such as, fuel cells, batteries, electrochemical capacitors, etc. In this research work, nickel oxide nanoparticles were synthesized by combustion route in presence of organic fuels such as, glycine, glucose and and urea. The prepared nickel oxide nanoparticles were calcined at 600℃ for 3 h to get phase pure materials. The calcined nanoparticles were preliminarily characterized by XRD, particle size analysis, SEM and EDAX. To prepare nickel oxide electrode materials for application in supercapacitors, the calcined NiO nanoparticles were mixed with di-methyl-acetamide and few drops of nafion solution for 12 to 16 h. The above slurry was coated in the graphite sheet and dried at 50℃ for 2 to 4 h in a hot air oven to remove organic solvent. The dried sample was subjected to electrochemical studies, such as cyclic voltammetry, AC impedance analysis and chrono-coulometry studies in KOH electrolyte medium. From the above studies, it was found that nickel oxide nanoparticles prepared by combustion synthesis using glucose as a fuel exhibited resulted in low particle diameter (42.23 nm). All the nickel oxide electrodes have shown better good capacitance values suitable for electrochemical capacitor applications.

• Journal of the Korean Magnetics Society
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• v.17 no.3
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• pp.133-136
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• 2007

We investigated the changes of the magnetic properties in electroplated Permalloy thin films by a few organic additives added to the plating electrolytes. Under identical electroplating conditions, the crystalline orientations and the surface roughness of the plated thin films were different from those prepared with a pure electrolyte. These property changes reduced the coercivity and increased the magnetoimpedance ratio (MIR) up to 20%.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.11a
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• pp.186-188
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• 2004

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.927-930
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• 2013

We developed an electroplating process of cobalt nanowires of which line-widths were between 70 and 200 nm. The plating electrolyte was made of $CoSO_4$ and an organic additive, dimethyldithiocarbamic acid ester sodium salt (DAESA). DAESA in plating electrolytes had an accelerating effect and reduced the surface roughness of plated cobalt thin films. We obtained void-free cobalt nanowires when the plating current density was 6.25 mA/$cm^2$ and DAESA concentration was 1 mL/L.