• Title/Summary/Keyword: Carbon cryogel

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Preparation and Electrochemical Properties of Carbon Cryogel for Supercapacitor

  • Song, Min-Seob;Nahm, Sahn;Oh, Young-Jei
    • Journal of the Korean Ceramic Society
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    • v.45 no.11
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    • pp.662-666
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    • 2008
  • Electrochemical properties of carbon cryogel electrode for the application of composite electrode materials mixed with metal oxide in supercapacitor have been studied. Carbon cryogels were synthesized by sol-gel polycondensation of resorcinol with form aldehyde, followed by a freeze drying, and then pyrolysis in an inert atmosphere. Physical properties of carbon cryogel were characterized by BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that carbon cryogel is amorphous material. The electrochemical properties of carbon cryogel were measured by cyclic voltammetry as a function of concentration of liquid electrolyte, galvanostatic charge-discharge with different scan rates and electrochemical impedance measurements. The result of cyclic voltammetry indicated that the specific capacitance value of a carbon cryogel electrode was approximately 150.2 F/g (at 5 mV/s in 6M KOH electrolyte).

Measurement of Adsorption Characteristic Using a Quartz Crystal Resonator (수정진동자를 이용한 흡착특성의 측정)

  • Kim, Byoung Chul;Sung, Ick Gi;Yamamoto, Takuji;Kim, Young Han
    • Korean Chemical Engineering Research
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    • v.47 no.3
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    • pp.368-372
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    • 2009
  • A technique to measure the adsorption characteristic of surface area and pore size distribution is proposed and its performance is examined. While the existing equipment utilizes liquid nitrogen, the proposed uses carbon dioxide at the room temperature leading to the small measuring device with easy operation and short measurement time. The performance of the device has been examined with micro-particle carbon cryogel and bamboo activated carbon. The results from the proposed device compared with those of the adsorption apparatus indicate that the measurement of meso-porous material is comparable but micro-porous material gives some error.

Development of On-Line Measurement System for Adsorption Process (흡착공정용 온라인 측정시스템의 개발)

  • Kim, Byoung Chul;Lee, Ki Sung;Yamamoto, Takuji;Kim, Young Han
    • Korean Chemical Engineering Research
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    • v.47 no.3
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    • pp.321-326
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    • 2009
  • A simple measuring device is proposed, and its performance is examined in an adsorption process separating a gas mixture. The sensor is made of a quartz crystal resonator and solid adsorbent to detect the target component. Micro-particle carbon cryogel(MCC) is utilized as the adsorbent, and the gas mixture of air and i-butane are separated in a column containing bamboo activated carbon. Two devices are placed at the inlet and outlet of the column. The measurements are compared with those of GC outcome to prove the measurements are effective. The experimentally proved system is simple and capable to be implemented in an in-line system with on-line measurement.

A Study on Sol-gel Preparation of Pt-Ru/C Anode Catalysts for Direct Methanol Fuel Cells (솔-젤 합성에 의한 직접 메탄올 연료전지용 고분산 Pt-Ru/C 음극 촉매의 제조)

  • Lee, Kang-Hee;Kim, Il-Gon;Park, Tae-Jin;Suh, Dong-Jin
    • Journal of the Korean Electrochemical Society
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    • v.6 no.1
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    • pp.13-17
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    • 2003
  • Cryogel and aerogel Pt-Ru/C were synthesized by the sol-gel process for the electrooxidation of methanol. From XRD analysis, it was found that the catalysts had highly dispersed Pt-Ru alloys on carbon support although high temperature treatments have been conducted. Electrocatalytic activities of 3 type aerogel catalysts were investigated in half cell experiments by cyclic voltammetry. Among them, Phloroglucinol-Formaldehyde(PF) type catalyst shows the highest activity. From the results of deactivation test for each catalysts, the aerogel catalysts are found to have excellent durability compared with those prepared by colloidal method.

Adiabatic Performance of Layered Insulating Materials for Bulk LH2 Storage Tanks (대용량 액체 수소 저장탱크를 위한 다층단열재의 단열성능 분석)

  • KIM, KYEONGHO;SHIN, DONGHWAN;KIM, YONGCHAN;KARNG, SARNG WOO
    • Journal of Hydrogen and New Energy
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    • v.27 no.6
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    • pp.642-650
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    • 2016
  • One of the most feasible solution for reducing the excessive energy consumption and carbon dioxide emission is usage of more efficient fuel such as hydrogen. As is well known, there are three viable technologies for storing hydrogen fuel: compressed gas, metal hydride absorption, and cryogenic liquid. In these technologies, the storage for liquid hydrogen has better energy density by weight than other storage methods. However, the cryogenic liquid storage has a significant disadvantage of boiling losses. That is, high performance of thermal insulation systems must be studied for reducing the boiling losses. This paper presents an experimental study on the effective thermal conductivities of the composite layered insulation with aerogel blankets($Cryogel^{(R)}$ Z and $Pyrogel^{(R)}$ XT-E) and Multi-layer insulation(MLI). The aerogel blankets are known as high porous materials and the good insulators within a soft vacuum range($10^{-3}{\sim}1$ Torr). Also, MLI is known as the best insulator within a high vacuum range(<$10^{-6}{\sim}10^{-3}$ Torr). A vertical axial cryogenic experimental apparatus was designed to investigate the thermal performance of the composite layered insulators under cryogenic conditions as well as consist of a cold mass tank, a heat absorber, annular vacuum space, and an insulators space. The composite insulators were laminated in the insulator space that height was 50 mm. In this study, the effective thermal conductivities of the materials were evaluated by measuring boil-off rate of liquid nitrogen and liquid argon in the cold mass tank.