• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.124-132
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• 2007

This work investigated a fabrication way of stable platinized Ti electrode and evaluated the electrochemical characteristics of the Sn-modified platinized Ti electrode in nitrate solution. A Pt electro-plating way to form some open special clearances within the Pt coating layer on etched Ti substrate was very important to remove effectively the residual contaminate due to plating solution out of the fabricated electrode surface and to maximize the actual electrode surface area contacting solution. Both boiling and electro-cleaning processes of the fabricated electrode was essential to obtain a stable platinized-Pt electrode with reproducible and stable surface property which was necessary for the correct evaluation of Sn coverage on the electrode. The electro-cleaning caused a morphology change of the platinized Ti electrode surface with some downy hair-like polyps formed during the deposition disappearing, which made the electrode stable. The Sn-modified platinized Ti electrode in this work showed the best electro-activity for nitrate reduction, when it was fabricated through the Pt electro-plating of about 30 minutes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.12
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• pp.1015-1020
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• 2012

Resistance of the front electrode is the highest proportion of the ingredients of the series resistance in crystalline silicon solar cell. While resistance of the front electrode is decreased with larger area, it induces the optical loss, causing the conversion efficiency drop. Therefore the front electrode with high aspect ratio increasing its height and decreasing is necessary for high-efficiency solar cell in considering shadowing loss and resistance of front electrode. In this paper, we used the screen printing method to form high aspect ratio electrode by multiple printing. Screen printing is the straightforward technology to establish the electrodes in silicon solar cell fabrication. The several printed front electrodes with Ag paste on silicon wafer showed the significantly increased height and slightly widen finger. As a result, the resistance of the front electrode was decreased with multiple printing even if it slightly increased the shadowing loss. We showed the improved electrical characteristics for c-Si solar cell with repeatedly printed front electrode by 0.5%. It lays a foundation for high efficiency solar cell with high aspect ratio electrode using screen printing.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.6
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• pp.366-371
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• 2017

In this paper, we introduce an electrocardiogram (ECG) system designed to solve problems caused by wetgels and motion artifacts in measuring active movement. The system is called a dry-contact ECG and was designed by considering impedance matching between skin and electrode as well as the frictional electricity between electrode and clothes. In order to create the system, we measured impedance on the skin-electrode interface, and the result was applied to the electronic circuit scheme. Moreover, we added an electrode on the back of the measurement electrode to make a flow path to ground the electrical noise. The final ECG circuit and novel electrode were used to detect real human cardiac signals from a subject who was tested while standing still and walking. The signals obtained from the two activities were nicely shaped, without any motion artifact noise. We took electrode size into account in this study because the impedance depended on the area of the electrode. An electrode of 50 mm diameter showed the best curve for the ECG signal without any electrical noise.

• Korean Journal of Materials Research
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• v.32 no.5
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• pp.270-279
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• 2022

In this study, N/S co-doped carbon felt (N/S-CF) was prepared and characterized as an electrode material for electric double-layer capacitors (EDLCs). A commercial carbon felt (CF) was immersed in an aqueous solution of thiourea and then thermally treated at 800 ℃ under an inert atmosphere. The prepared N/S-CF showed a large specific surface area with hierarchical pore structures. The electrochemical performance of the N/S-CF-based electrode was evaluated using both 3-electrode and 2-electrode systems. In the 3-electrode system, the N/S-CF-based electrode showed a good specific capacitance of 177 F/g at 1 A/g and a good rate capability of 41% at 20 A/g. In the 2-electrode system (symmetric capacitor), the freestanding N/S-CF-based electrode showed a specific capacitance of 275 mF/cm² at 2 mA/cm², a rate capability of 62.5 % at 100 mA/cm², a specific power density of ~ 25,000 mW/cm² at an energy density of 23.9 mWh/cm², and a cycling stability of ~ 100 % at 100 mA/cm² after 20,000 cycles. These results indicate the N/S co-doped carbon felts can be a promising candidate as a new electrode material in a symmetric capacitor.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1544-1546
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• 1999

The fabrication process for ceramic fuel cell with a large electrode area was investigated. A cofired cell of two layer, electrolyte/anode, yielded a power of $200mW/cm^2$. Its performance loss was mainly due to iR drop in the anode side. The performance of the cofired of three layer. cathode/electrolyte/ anode, was much lower than that of two layer, which resulted from the large iR drop and overvoltage at the cathode side. Also a flat cell with a large area of $7.7{\times}10.8cm^2$ was fabricated successfully and tested using ceramic and metallic interconnectors. The large cell with metallic interconnectror showed a good performance of 0.6 V, 4.5 A.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.853-856
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• 2002

Present. direct method x-ray conversion detector is studied by abroad medical instrument and country with amorphous Selenium. And we search the method for large area x-ray detector. Amorphous-Selenium based photoreceptor is widely used on the X-ray conversion materials. But amorphous-selenium based x-ray conversion detector is broken by high voltage and leakage defect point. In this paper, We investigated top-electrode distance rate to improve defect point and high voltage broken. The result to appoint to made large area x-ray conversion detector with base data.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1135-1138
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• 2003

A direct light type backlight for large-area LCD-TVs using External Electrode Fluorescent Lamps (EEFLs) has been developed. The brightness was $450cd/m^{2}$(nit) and the luminous uniformity (max/min) was 1.3. The mechanical design of backlight was optimized and the reliability of lamps was secured. As a result, the possibility of backlight with EEFLs for large area LCD-TVs was sufficiently proved.

• Journal of the Korean Electrochemical Society
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• v.10 no.3
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• pp.203-206
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• 2007

Electrochemical reaction of glucose was regulated by the electrochemically active area of nanoporous platinum, which is controlled by ionic strength. The profile of the oxidation current of glucose vs. ionic strength was identical with that of the electrochemically active area. This result confirms that the nanopores are virtually opened for the electrochemical reaction of glucose when the ionic strength climbs over a specific concentration and implies that the electrochemical reactions on nanoporous electrode surfaces can be controlled by concentration of electrolyte.

• Transactions of the Korean hydrogen and new energy society
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• v.7 no.1
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• pp.11-18
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• 1996

The Laves phase alloy hydrides have some promising properties as electrode materials in reversible metal hydride batteries. In this work, the hydrogen storage performance, crystallographic parameters, surface morphology, surface area and electrochemical characteristics of the non-stoichiometric $ZrMn_{0.3}V_{0.7}Ni_{1.4+{\alpha}}$, $ZrMn_{0.5}V_{0.5}Ni_{1.4+{\alpha}}$($\alpha$ =0.0, 0.2, 0.4, 0.6) alloys were examined. These as-cast alloys were found to have mainly a cubic C15-type Laves phase structure by X -ray diffraction analysis. The equilibrium pressure of the alloy were increased as $\alpha$ increased in both two types alloy. In case of $ZrMn_{0.5}V_{0.5}Ni_{1.4+{\alpha}}$ alloys, discharge efficiency and the rate capability of the alloy were decreased as $\alpha$ increased but, these values were increased in case of $ZrMn_{0.3}V_{0.7}Ni_{1.4+{\alpha}}$ alloys. The differences of these electrode properties observed were dependent on the reaction surface area and the catalytic activity of unit area of the each electrode.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.315-324
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• 2006

This research was conducted to clarify the characteristics of electrochemical decolorization of effluent discharged from a biological animal wastewater treatment process and to finally establish parameters or mode for optimum operation of electrolysis system. Average color unit of wastewater was about 1,200 and DSA(Dimensionally Stable Anode) was used as electrode. Experiments were performed with two different operation conditions or modes, fixed voltage-free current(Run A) and free voltage-fixed current(Run B). Color removal rate was proportional to the electrode area and electrical conductivity, and an equation subject to them at a condition of fixed voltage was derived as follows; Ct=C0ekt, k=[{0.0121×ａ(dm2)× c(mS/cm)}+0.0288], [where, C0: initial color, Ct: color unit after treatment for t, k: reaction coefficient, t: time(min.), ａ: electrode area, c: conductivity]. From the study on the effects of current density on color removal, it was revealed that the removal efficiency of color was function of the current density, showing direct proportion. However, when considered energy consumption rate, maintenance of low current density was an economical way. Based on the obtained results, it was concluded that supplementation of electrolyte is not necessary for the removal of color from the effluent of secondary treatment process and operation with the mode of free voltage-fixed current, rather than operation with fixed voltage-free current mode, would be an efficient way to increase the removal performance and capacity per consumed energy.