• Title/Summary/Keyword: Foam Collector

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Supercapacitive Properties of Co-Ni Mixed Oxide Electrode Adopting the Nickel Foam as a Current Collector

  • Cho, Hyeon Woo;Nam, Ji Hyun;Park, Jeong Ho;Kim, Kwang Man;Ko, Jang Myoun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.3993-3997
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    • 2012
  • Three-dimensional porous nickel foam was used as a current collector to prepare a Co-Ni oxide/Ni foam electrode for a supercapacitor. The synthesized Co-Ni oxide was proven to consist of mixed oxide phases of $Co_3O_4$ and NiO. The Co-Ni oxide/Ni foam electrode prepared was characterized by morphological observation, crystalline property analysis, cyclic voltammetry, and impedance spectroscopy. Cyclic voltammetry for the electrode showed high specific capacitances, such as 936 F $g^{-1}$ at 5 mV $s^{-1}$ and 566 F $g^{-1}$ at 200 mV $s^{-1}$, and a comparatively good cycle performance. These improved results were mainly due to the dimensional stability of the nickel foam and its high electrical contact between the electrode material and the current collector substrate.

Effect of Nickel Foam Current Collector on the Supercapacitive Properties of Cobalt Oxide Electrode (코발트 산화물 전극의 수퍼커페시터 성질에 미치는 니켈 폼 집전체 효과)

  • Yoon, Yu-Il;Kim, Kwang-Man;Ko, Jang-Myoun
    • Journal of the Korean Ceramic Society
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    • v.45 no.6
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    • pp.368-373
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    • 2008
  • An electrode for supercapacitor using 3-dimensional porous nickel foam as a current collector and cobalt oxide as an active material was prepared and characterized in terms of morphology observation, crystalline property analysis, and the investigation of electrochemical property. The electrode surface showed that the cobalt oxide was homogeneously coated as the crystalline phase of $Co_3O_4$. Cyclic voltammetry for the $Co_3O_4$/nickel foam electrode exhibited higher specific capacitance values (445 F/g at 10 mV/s and 350 F/g at 200 mV/s) and excellent capacitance retention ratio (99% after $10^4$ cycles). It was proved that the nickel foam substrate played the roles in reducing the interfacial resistance with cobalt oxide and in improving the electrode density by embedding greater amount of cobalt oxide within it.

SnO2-Coated 3D Etched Cu Foam for Lithium-ion Battery Anode

  • Um, Ji Hyun;Kim, Hyunwoo;Cho, Yong-Hun;Yoon, Won-Sub
    • Journal of Electrochemical Science and Technology
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    • v.11 no.1
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    • pp.92-98
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    • 2020
  • SnO2-based high-capacity anode materials are attractive candidate for the next-generation high-performance lithium-ion batteries since the theoretical capacity of SnO2 can be ideally extended from 781 to 1494 mAh g-1. Here 3D etched Cu foam is applied as a current collector for electron path and simultaneously a substrate for the SnO2 coating, for developing an integrated electrode structure. We fabricate the 3D etched Cu foam through an auto-catalytic electroless plating method, and then coat the SnO2 onto the self-supporting substrate through a simple sol-gel method. The catalytic dissolution of Cu metal makes secondary pores of both several micrometers and several tens of micrometers at the surface of Cu foam strut, besides main channel-like interconnected pores. Especially, the additional surface pores on etched Cu foam are intended for penetrating the individual strut of Cu foam, and thereby increasing the surface area for SnO2 coating by using even the internal of Cu foam. The increased areal capacity with high structural integrity upon cycling is demonstrated in the SnO2-coated 3D etched Cu foam. This study not only prepares the etched Cu foam using the spontaneous chemical reactions but also demonstrates the potential for electroless plating method about surface modification on various metal substrates.

Experimental study on applicability of compressed air foam fire water using seawater in train fire at subsea tunnel rescue station (해저터널 구난역 열차화재시 압축공기포 소화용수의 해수 적용성에 관한 실험 연구)

  • Park, Byoung-Jik;Shin, Hyun-Jun;Yoo, Yong-Ho;Park, Jin-Ouk;Kim, Hwi-Seong;Kim, Yang-Kyun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.5
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    • pp.705-715
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    • 2017
  • In this study, applicability of compressed air form (CAF) fire water was verified in a bid to use the undersea effluent as fire water. Foam collector was fabricated in accordance with KS B ISO 7203-1 (Specification for low expansion foam concentrates for top application to water-immiscible liquids) and the test was conducted using fresh water as fire water for 19 times and using seawater as fire water 15 times that totaled 34 times. Foam reduction time was 237.73 seconds on average with fresh water and 215.60 seconds with seawater, which proved the applicability of CAF fire water using seawater. Besides, window breaker was fabricated to directly extinguish the fire in train and a full-scale fire test was conducted three times. At the final 3rd test, window glass was broken in 2 seconds to make the hole for fire extinguishing and suppressed the fire in 3 seconds using CAF fire extinguisher.

Nickel Oxide Nano-Flake Films Synthesized by Chemical Bath Deposition for Electrochemical Capacitors (CBD(Chemical Bath Deposition) 법으로 제조된 전기화학식 캐패시터용 NiO 나노박편 필름)

  • Kim, Young-Ha;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.163.2-163.2
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    • 2010
  • In this work, nano-flake shaped nickel oxide (NiO) films were synthesized by chemical bath deposition technique for electrochemical capacitors. The deposition was carried out for 1 and 2 h at room temperature using nickel foam as the substrate and the current collector. The structure and morphology of prepared NiO film were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). And, electrochemical properties were characterized by cyclic voltammetry, galvanostatic charge-discharge, and AC impedence measurement. It was found that the NiO film was constructed by many interconnected NiO nano-flakes which arranged vertically to the substrate, forming a net-like structure with large pores. The open macropores may facilitate the electrolyte penetration and ion migration, resulted in the utilization of nickel oxide due to the increased surface area for electrochemical reactions. Furthermore, it was found that the deposition onto nickel foam as substrate and curent collector led to decrease of the ion transfer resistance so that its specific capacitance of a NiO film had high value than NiO nano flake powder.

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TWO-STEP THERMOCHEMICAL CYCLES FOR HYDROGEN PRODUCTION WITH DISH TYPE SOLAR THERMAL SYSTEM (접시형 태양열 집광 시스템을 이용한 열화학 사이클의 수소생산)

  • Kwon, Hae-Sung;Oh, Sang-June;Seo, Tae-Beom
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.169-176
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    • 2011
  • The two-step water splitting thermochemical cycle is composed of the T-R (Thermal Reduction)and W-D (Water Decomposition)steps. The mechanism of this cycle is oxidation-reduction, which produces hydrogen. The reaction temperature necessary for this thermochemical cycle can be achieved by a dish-type solar thermal collector (Inha University, Korea). The purpose of this study is to validate a water splitting device in the field. The device is studied and fabricated by Kodama et al (2010, 2011). The validation results show that the foam device, when loaded with $NiFe_2O_4/m-ZrO_2$powder, was successfully achieved hydrogen production with 9 (10 with a Xe-light solar simulator, 2009, Kodama et al.) repeated cycles under field conditions. Two foam device used in this study were tested for validation before an experiment was performed. The lab scale ferrite-conversion rate was in the range of 24~76%. Two foam devices were designed to for structural stability in this study. In the results of the experiments, the hydrogen percentage of the weight of each foam device was 7.194 and $9.954{\mu}mol\;g^{-1}$ onaverage, and the conversion rates 4.49~29.97 and 2.55~58.83%, respectively.

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Adsorptive Bubble Separation of Zinc (II) Using Capric Acid as Collector (추출제로 카프르산을 사용한 아연(II)의 흡착 기포 분리)

  • Chung Hee Kwak;Chul Lee
    • Nuclear Engineering and Technology
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    • v.15 no.2
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    • pp.149-153
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    • 1983
  • The removal of zinc (II) from aqueous solutions has been studied by the adsorptive bubble separation processes such as solvent sublation and foam fractionation processes using capric acid as collector. The efficiency of the remoal process has been studied by changing the ionic strength and pH and the bubble separation method has been compared with the solvent extraction process using the capric acid dissolved in benzene as extractant.

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CoMn Oxide/Carbon-nanofiber Composite Electrodes for Supercapacitors (코발트망간 산화물/탄소나노섬유 복합전극의 수퍼케폐시터 특성)

  • Kim, Yong-Il;Yoon, Yu-Il;Ko, Jang-Myoun
    • Journal of the Korean Ceramic Society
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    • v.45 no.8
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    • pp.493-496
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    • 2008
  • Composite electrodes consisting of $CoMnO_2$ and carbon nanofibers(vapor grown carbon nanofiber, VGCF) with high electrical conducivity($CoMnO_2$/VGCF) were prepared on a porous nickel foam substrate as a current collector and their supercapacitive properties were investigated using cyclic voltammetry in 1 M KOH aqueous solution. The $CoMnO_2$/VGCF electrode exhibited high specific capacitance value of 630 F/g at 5 mV/s and excellent capacitance retention of 95% after $10^4$ cycles, indicating that the used VGCF played the important roles in reducing the interfacial resistance in the composite electrode to improve supercapacitive performance.

TWO-STEP THERMOCHEMICAL CYCLES FOR HYDROGEN PRODUCTION WITH DISH TYPE SOLAR THERMAL SYSTEM and $CeO_2/NiFe_2O_4$ (접시형 태양열 집광 시스템과 산화세륨 및 페라이트산화물을 이용한 열화학 사이클의 수소생산)

  • Kwon, Hae-Sung;Oh, Sang-June;Seo, Tae-Beom
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.113-119
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    • 2012
  • The two-step water splitting thermochemical cycle is composed of the T-R (Thermal Reduction) and W-D (Water Decomposition) steps. The mechanism of this cycle is oxidation-reduction, which produces hydrogen. The reaction temperature necessary for this thermochemical cycle can be achieved by a dish-type solar thermal collector (Inha University, Korea). The purpose of this study is to validate a water splitting device in the field. The device is studied and fabricated by Kodama et al (2010, 2011). The validation results show that the foam device, when loaded with $CeO_2$ powder, was successfully achieved hydrogen production under field conditions. Through this experiment, we can analyze the characteristics of the catalyst and able to determine which is more advantageous thing to produce hydrogen compared with previous experiment that used ferrite-device.

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