• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.152-153
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• 2015

알루미늄 공기전지의 환원전극으로 많은 재료들이 쓰이고 있지만 그중에서도 니켈은 값이 싸며 전기 전도도가 높아 많이 쓰이고 있다. 니켈 메쉬표면에 이산화망간을 촉매로써 처리하지만 이산화망간 용액을 적시고 말리는 기존방법에서는 균일하게 처리가 되지 않고 공기가 통하지 않는 경우도 있기 때문에 보다 균일한 처리를 위해 전해도금을 연구하였다.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.614-622
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• 2006

A Study on the characteristics of $Ta/Ta_2O_5/MnO_2$ capacitor applied $MnO_2$ by means of pyrolysis of manganese nitrate solution was carried out. Single phase of $MnO_2$ was obtained in the pyrolysis temperature range of 230 to $250^{\circ}C$ by TG/DSC analysis on manganese nitrate solution. Temperature of pyrolysis, concentration of manganese nitrate solution and the number of pyrolysis were selected for the basic parameters of embodying $MnO_2$ solid electrolyte and then the effects of these parameters on the characteristics of capacitor were estimated. The characteristics of capacitor pyrolyzed radiationally was superior to that of capacitor pyrolyzed convectionally on the basis of these optimized parameter conditions. It was verified that radiational pyrolysis formed smaller spherical $MnO_2$ particles than those of convectional one relatively and these facts resulted in forming uniform and dense solid electrolyte layer into the microporous sintered body of capacitor.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.49-53
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• 2019

Hydrous $MnO_2$ nanowires were easily synthesized by an one-pot synthesis with a simple hydrothermal method. As prepared hydrous $MnO_2$ nanowires were characterized with scanning emission microscopy (SEM), transmit emission microscopy (TEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET). They showed a good catalytic activity with the suitable nano-size of 4-5 nm and morphology. The furfuryl alcohol was selected as a substrate and the reaction was carried out in a toluene solvent at $100^{\circ}C$ under the atmospheric pressure of oxygen. The hydrous $MnO_2$ nanowire catalyst exhibited an excellent yield of furfural with the first-rate selectivity and conversion. The catalytic performance during recycle tests was also carried out and the catalyst showed a good mechanical strength with a negligible loss in the activity over five reaction cycles.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.245-250
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• 2016

Manganese dioxide is the material which has a good characteristic property for a secondary cell. We have surveyed on rechargeable battery of zink-manganese dioxide using aqueous solution and we also surveyed on redox reversibility of zink-manganese dioxide for checking up possibility for a secondary cell. We have found out to be active for charging and discharging of those.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.750-759
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• 2016

The $MnO_2$ electrodeposited on the surface of the carbon nanofiber mats ($MnO_2$-LCNFM) were prepared from electrospun lignin-g-PAN copolymer via heat treatments and subsequent $MnO_2$ electrodeposition method. The resulting $MnO_2$-LCNFM was evaluateed for its potential use in a supercapicitor electrode. The increase of $MnO_2$ electric deposition time was revealed to increase diameter of carbon nanofibers as well as $MnO_2$ content on the surface of carbon nanofiber mats as confirmed by scanning electon microscope (SEM) analysis. The electrochemical properties of $MnO_2$-LCNFM electrodes are evaluated through cyclic voltammetry test. It was shown that $MnO_2$-LCNFM electrode exhibited good electrochemical performance with specific capacitance of $168.0mF{\cdot}cm^{-2}$. The $MnO_2$-LCNFM supercapacitor successfully fabricated using the gel electrolyte ($H_3PO_4$/Polyvinyl alcohol) showed to have the capacitance efficiency of ~90%, and stable behavior during 1,000 charging/discharging cycles.

• Journal of the Korean Chemical Society
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• v.41 no.10
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• pp.541-546
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• 1997

Manganese dioxide may react with silicon tetrachloride to form manganese(Ⅳ) oxodichloride which reacts subsequently with another molecule of silicon tetrachloride leading to manganese tetrachloride eventually in chlorinated solvents. This in situ generated manganese(Ⅳ) oxodichloride or manganese tetrachloride were found to be very effective for the chlorination of a wide variety of alcohols to the corresponding chlorides. Primary, secondary and benzylic alcohols were converted into corresponding chlorides when treated with silicon tetrachloride in the presence of manganese dioxide at room temperature.

• Journal of Digital Contents Society
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• v.18 no.6
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• pp.1199-1205
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• 2017

Global energy consumption is rapidly increasing yearly due to drastic industrial advances, requiring the development of new energy storage devices. For this reason, supercapacitors with fast charge-discharge, long life cycle and high power density is getting attention, and have been considered as one of the potential energy storage systems. In this research, we developed a supercapacitor that consists of amorphous manganese oxide($MnO_2$) electrodes deposited onto carbon cloth substrates using the hydrothermal method. The Fe-doped amorphous $MnO_2$ samples were characterized by X-ray diffraction(XRD), Energy Dispersive X-ray spectroscopy(EDX), as well as scanning electron microscopy(SEM). The electrochemical analysis of the prepared samples were performed using cyclic voltammetry and galvanostatic charge-discharge measurements in 1M $Na_2SO_4$ electrolyte. The test results demonstrate that the supercapacitor based on the Fe-doped amorphous $MnO_2$ electrodes has a specific capacitance as high as 163F/g at 1A/g current density, and good cycling stability of 87.34% capacitance retention up to 1000 cycles.

• Journal of the Korean Professional Engineers Association
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• v.18 no.3
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• pp.45-54
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• 1985

이산화망간 건전지에 실사용되고 있는 전해액 ZnCl$_2$-$H_2O$의 조성 변화에 따른 건전지의 특성변화를 비교 검토하여, 건전지성능향상의 기본인자 및 그 변화정도를 조사코자 하였다. ZnCl$_2$ 주사용 전지계는 특히 중부하연속방전이 우수하였으며 그 이유로는 농도분극현상이 적음에 기인되며 이는 $Zn^{++}$이 본계에서는 쉽게 이동함에 있다고 간주되며 그 $Zn^{++}$ 이온의 바른 이동은 이론치보다도 다량사용하게 되는 물의 역할에 기인되고 방전에 직접 필요한 수분량과, 기타의 목적 즉 반응 침전물의 재용해, ion carrier 등으로서 이용되는 수분량은, MnO$_2$와의 비율 및 방전 부하크기에 따라 다르다.

• Proceedings of the Materials Research Society of Korea Conference
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• 1996.11a
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• pp.11-11
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• 1996

• Resources Recycling
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• v.6 no.4
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• pp.11-16
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• 1997

The wastewater resulted from the process of developing and fuing for x-ray film manufachlring contains a lot of silvercomponent. The average concentation of silver-component is about 1,500 mgA. The wastewater contained silver-component is toxic when it is discharged to the natural ecosystem. So that we must to do pretreatment of wastewater prior to discharge. There are electrolysis. chemical precipitation, and metallic replacement as conventional lreabent proccss of fixer wastewater of x-ray film. Adsorption of silver-component in x-ray fkcr wastewater was carricd out this study. 'Ille manganese dioxide (MDO) reagent and the recovered manganese dioxide (RMDO) from the waste dry-cell were used for adsarbents. Adsorption of silvercomponent was wrried out at the batch and continuous type experimental equipment. The adsorption experiment results were obtained bom silver-component have some diifcrences according to adsorhents. The adsorption results of manganese dioxide reagent (MDO) were better ihan those of waste dry-ccU (RMDO), but the manganese dloxide recovered fmm waste dry-cell (RMDO) will be able la recognized as good adsorbent too.