• New & Renewable Energy
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• v.4 no.1
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• pp.11-18
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• 2008

In-situ lithiated NiO has been manufactured as a conventional cathode material of molten carbonate fuel cell (MCFC), however this material has a weakness for commercialization of MCFC because NiO is spontaneously dissolved into the electrolyte under MCFC operating conditions, resulting in short circuit between cathode and anode. In this research, therefore, $Co(OH)_2$-coated Ni powder was prepared by precipitation method with controlling pH at low temperature and atmospheric pressure. Modified cathode was fabricated by a conventional tape casting method and sintered at 700$^{\circ}C$ in a $H_2/N_2$ atmosphere, Based on characterization result, Pore size distribution and porosity was suitable for the cathode of MCFC. According to the result of dissolution, Ni solubility of modified cathode was 33% lower than that of conventional cathode. In addition, modified electrode showed a good performance from the single cell operation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05b
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• pp.22-25
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• 2001

A thyristor switch circuit for capacitor discharge application, of which the equivalent circuit includes a resistor between cathode and gate of a reverse-conducting thyristor and an avalanche diode anti-parallel between its anode and gate to set thyristor tum-on voltage, is monolithically integrated by planar process with AVE double-implantation method. To ensure a lower breakdown voltage of the avalanche diode for thyristor tum-on than the break-over voltage of the thyristor, $p^+$ wells on thyristor p base layer are made by boron implantation/drive-in for a steeper doping profile with higher concentrations while rest p layers of thyristor and free-wheeling diode parts are formed with Al implantation/drive-in for a doping profile of lower steepness. The free-wheeling diode part is isolated from the thyristor part by formation of separated p-well emitter for suppressing commutation between them, which is achieved during the formation of thyristor p-base layer.

• Journal of Hydrogen and New Energy
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• v.20 no.1
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• pp.1-8
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• 2009

Hydrogen production by the reaction of aluminum alloys and NaOH solution was studied for an automotive proton exchange membrane fuel cell(PEMFC) application. In our experiment conditions($30{\sim}75^{\circ}C$, NaOH $0.5{\sim}5M$), passivation of aluminum was not occurred. Higher rate of hydrogen production was observed at the reaction with Al alloys that contain impurities. With an increase in reaction temperature, hydrogen production rate by an increase in NaOH concentration increased much. When hydrogen was fed into the anode without filtering, PEMFC cell performance decreased 35% by ionic contamination such as $Na^+$ on the membrane and electrode. Thus, filtering of produced hydrogen is necessary for PEMFC operation.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.240.2-240.2
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• 2014

Characteristics of pulse-discharged plasma in liquid and its biological applications to proteins are investigated by making use of high voltage Marx generator. The Marx generator has been consisted of 5 stages, where each charging capacitor is $0.5{\mu}F$ to generate a high voltage pulse with rising time of $1{\mu}s$. We have applied an input voltage of 6 kV to the each capacitor of $0.5{\mu}F$. The high voltage pulsed plasma has been generated inside a polycarbonate tube by a single-shot operation, where the breakdown voltage is measured to be 7 kV, current of 1.2 kA, and pulse width of ${\sim}1{\mu}s$ between the two electrodes of anode-cathode made of stainless steel, which are immersed into the liquids. For the investigation of the influence of pulsed plasma on biomolcules, we have focused on the amino acids, DNA, proteins, cell and cholesterol.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.3
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• pp.49-55
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• 2022

The design of a battery package and a BMS module for applications using seawater rechargeable batteries, which are known as next-generation energy storage devices, is proposed herein. Seawater rechargeable batteries, which are currently in the initial stage of research, comprise primarily components such as anode and cathode materials. Their application is challenging owing to their low charge capacity and limited charge/discharge voltage and current. Therefore, we design a method for packaging multiple cells and a BMS module for the safe charging and discharging of seawater rechargeable batteries. In addition, a prototype seawater rechargeable battery package and BMS module are manufactured, and their performances are verified by evaluating the prevention of overcharge, overdischarge, overcurrent, and short circuit during charging and discharging.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.4
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• pp.145-150
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• 2007

The $SiO_2$ and $TiO_2$ thin films for the multilayer interference filter application were manufactured by electron beam process. In case of electron beam process with ion source, the anode current was controlled by gas volume ratio of $O_2$ and Ar. Substrate temperature of electron beam deposition without ion source was increased from 100 to $250^{\circ}C$ with $50^{\circ}C$ increment. The surface roughness values of $SiO_2$ thin films was most low value at $200^{\circ}C$ substrate temperature and 0.2 A anode current respectively. And the surface roughness values of $TiO_2$ thin films was most low value at room temperature and 0.2 A anode current repectively. The refractive index of $SiO_2$ and $TiO_2$ thin films to be deposited with ion source was usually lower than that of thin films without ion source.

• Clean Technology
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• v.30 no.3
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• pp.220-227
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• 2024

As the demand for lithium-ion batteries with high capacity and high energy density has rapidly increased, silicon anodes (theoretical capacity = 3,570 mA h g^-1) have garnered attention as potential replacements for conventional graphite anodes (theoretical capacity = 372 mA h g^-1). However, silicon anodes suffer from severe volume expansion (~360%) during lithiation, low ionic conductivity (10^-14 ~ 10^-13 cm² S^-1), and low electrical conductivity (10^-2 S cm^-1), resulting in poor cycling and rate performance. To address these issues, this study synthesized core@shell-structured silicon@carbon nanoparticles (Si@C NPs) via a one-pot spray pyrolysis process using Pluronic-F127. Pluronic-F127 in the spray solution contributes to the synthesis of nanoparticles by preventing the formation of silicon nanoparticle/dextrin agglomerates and by undergoing pyrolysis simultaneously. Additionally, dextrin derived amorphous carbon was coated on the surface of the silicon nanoparticles to act as an electron transport pathway within the anodes and enhance the electrical contact between the silicon nanoparticles. The Si@C NPs exhibited a discharge capacity of 1,912 mA h g^-1 after 50 cycles at 1.0 A g^-1 and high rate capabilities (discharge capacity of 1,493 mA h g^-1 at 3.0 Ag^-1). The silicon@carbon composite nanoparticle synthesis strategy based on the spray pyrolysis process presented in this study is expected to offer a new direction for improving the performance of silicon anode materials.

• Advances in Energy Research
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• v.2 no.2
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• pp.73-84
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• 2014

Fuel cells of proton exchange membrane type (PEMFC) working with hydrogen in the anode and ambient air in the cathode ('air breathing') have been prepared and characterized. The cells have been studied with variable thickness of the cathode catalyst layer ($L_{CL}$), maintaining constant the platinum and ionomer loads. Polarization curves and electrochemical active area measurements have been carried out. The polarization curves are analyzed in terms of a model for a flooded passive air breathing cathode. The analysis shows that $L_{CL}$ affects to electrochemical kinetics and mass transport processes inside the electrode, as reflected by two parameters of the polarization curves: the Tafel slope and the internal resistance. The observed decrease in Tafel slope with decreasing $L_{CL}$ shows improvements in the oxygen reduction kinetics which we attribute to changes in the catalyst layer structure. A decrease in the internal resistance with $L_{CL}$ is attributed to lower protonic resistance of thinner catalyst layers, although the observed decrease is lower than expected probably because the electronic conduction starts to be hindered by more hydrophilic character and thicker ionomer film.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.123.1-123.1
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• 2010

The solid oxide fuel cell (SOFC) has attracted great deal of attention due to its high electrical efficiency, high waste-heat utilization, fuel flexibility, and application versatility. However, SOFC technology is still not matured enough to fulfill the practical requirements for commercialization. Therefore, all the research and development activities are mainly focused on a development of practically viable SOFCs with higher performance and better reliability. We were successful in fabricating high-performance anode-supported unit cells by employing hierarchically controlled multi-layered electrodes for both structural reliability and high performance. In addition, a novel composite sealing gasket made it possible to achieve excellent sealing integrity even with considerable surface irregularities in a multi-cell planar arrayed stack.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.423-426
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• 1991

A Plasma Display Panel with Double Pulse Memory was fabricated and its luminance and luminous efficacy were investigated. Application of non-discharge pulses to an auxiliary anode increased luminance by 43% and luminous efficacy by 33%. Compared to PDP with PPM(Planar Pulse Memory) driving technique, PDP with DPM obtained higher luminous efficacy and consumed lower power with the same delay time.