Carbon/PVC 복합전극의 제조 및 전 바나듐계 레독스-흐름전지에의 응용

유철휘,장인영,정현철,김종철,강안수 대한안전경영과학회 2002 대한안전경영과학회 학술대회논문집 Vol.2002 No.1

나트륨을 활용한 이차전지 연구동향

유철휘,강성구,김진배,황갑진 한국수소및신에너지학회 2015 한국수소 및 신에너지학회논문집 Vol.26 No.1

The secondary battery using sodium is investigating as one of power storage system and power inelectric vehicles. The secondary battery using sodium as a sodium battery and sodium ion battery had merits suchas a abundant resources, high energy density and safety. Sodium battery (sodium molten salt battery) is operatedat lower temperature (100℃) compared to NAS and ZEBRA battery (300~350℃). Sodium ion battery isinvestigating as one of the post lithium ion battery. In this paper, it is explained for the principle and recent researchtrends in sodium molten salt and sodium ion battery.

분리판에서 기포의 거동에 관한 연구

유철휘,김종수,박대흠,정영관 한국수소및신에너지학회 2012 한국수소 및 신에너지학회논문집 Vol.23 No.5

The bubbles made of hydrogen and oxygen gases producted by electrolysis disturb the electrolysis,but the behavior of these bubbles in the electrolysis stack isn't clearly defined. In order to study on the behavior of bubbles in the flow pattern of the meshes type separator, the flow visualization experiment was performed by using of a visible alkaline electrolysis stack and a stereoscopic microscope. As the results, a fine size bubbles adhered to the separator's surface in the electrolyte solution have grown large sized bubbles until each bubble's buoyance is lager than the sum of surface adhesion force and weight. And then the large bubbles flow into the upper area of the separator. Also, as wide area of the separator have been occupied by various sized bubbles,the electrolysis efficiency is declined.

Carbon/PVC 복합전극의 제조 및 전 바나듐계 레독스-흐름전지에의 응용

유철휘,장인영,정현철,김종철,강안수 대한안전경영과학회 2002 대한안전경영과학회 학술대회논문집 Vol.2002 No.11

All-vanadium redox flow battery(VRFB) has been studied actively as one of the most promising electrochemical energy storage systems for a wide range of applications such as electric vehicles, photovoltaic arrays, and excess power generated by electric power plants at night time. CPCS has been shown to have the characteristics as an excellent current collector for VRFB and electrochemical properties of specific resistivity 0.31 Ω cm, which were composed of G-1028 80 wt%, PVC 10 wt%, DBP 5 wt% and FS 5 wt%. Energy efficiencies of VRFB with the CPCE and the existing electrode assembly were 84.14 % and 77.24 % respectively, in charge/discharge experiments at constant current of 200 mA, and the CPCE was confirmed to be suitable as the electrode of VRFB.

Zn-Br 레독스 흐름 전지용 격막에 관한 연구

나일채,조홍식,유철휘,황갑진 한국막학회 2014 멤브레인 Vol.24 No.5

두 종류의 막(다공성 막, 양이온교환막)을 사용하여 아연-브롬 레독스-흐름 전지(ZBRFB, Zn-Br redox-flow battery)의 성능을 평가하였다. ZBRFB의 성능평가는 20mA/cm2의 전류밀도에서 진행하였다. 다공성 막인 SF-600을 사용한 ZBRFB의 기전력(SOC 100%에서의 OVC)은 1.87 V, 양이온교환막인 Nafion117 막을 사용한 ZBRFB의 기전력은 1.93 V를 나타냈다. 각 막을 사용한 ZBRFB의 성능은 7회 충 방전 실험을 진행하여 평가하였다. SF600 막을 사용한 ZBRFB의 평균 전류효율은 89.76%, 평균 전압효율은 83.46%, 평균 에너지효율은 74.88%를 나타냈으며, Nafion117 막을 사용한 ZBRFB의 평균 전류효율은 97.7%, 평균 전압효율은 76.33%, 평균 에너지효율은 74.56%를 나타냈다. Two commercial membranes (porous membrane and cation exchange membrane) were evaluated as a separator in the Zn-Br redox-flow battery (ZBRFB). The performance properties of ZBRFB were test in the current density of 20mA/cm2. The electromotive forces (OCV at SOC 100%) of ZBRFB using SF-600 (porous membrane) and Nafion 117 (cation exchange membrane) were 1.87 V and 1.93 V, respectively. The cycle performance of ZBRFB using each membrane was evaluated during 7 cycles. The performance of ZBRFB using SF-600 membrane was 89.76%, 83.46% and 74.88% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of ZBRFB using Nafion117 membrane was 97.7%, 76.33% and 74.56% for average current efficiency, average voltage efficiency and average energy efficiency, respectively.

전 바나듐계 레독스-흐름전지의 응용을 위한 양이온 교환막의 제조

이한섭,유철휘,강안수 용인대학교 자연과학연구소 1996 自然科學硏究所論文誌 Vol.1 No.1

RFB (redox flow battery)에서의 이온교환막

길보민,유철휘,황갑진 한국막학회 2019 한국막학회 총회 및 학술발표회 Vol.2019 No.05

전 바나듐계 레독스-호름전지의 응용을 위한 양이온 교환막의 제조

강안수,유철휘,이한섭 용인대학교 자연과학연구소 1996 自然科學硏究所論文誌 Vol.1 No.1

Redox-flow battery has been studied actively as one of the most promising electrochemical energy storage systems for a wide range of applications such as electric vehicles, photovoltaic arrays, and excess power generated by electric power plants. By employing the same active material in both half-cell electrolytes, problems of cross-contamination inherent in other types of redox flow batteries, such as the Fe/Cr system, are eliminated in the all vanadium systems. To date, Selemion CMV and Nafion 117 as the cation exchange membrane have been the most widely used material in the research and development of all vanadium redox- flow battery. Despite of excellent results, the long-term stability of the Selemion CMV membrane in the all vanadium redox-flow battery is limited by the oxdizing nature of vanadium and Nafion 117 is too expensive. To solve these problems, the developement of cation exchange membrane that possess good chemical stability, high permselectivity and relatively inexpensive in comparison with the commercial membranes, is necessary. Based on 16, 20, 40, 50 and 60 ㎛ thickness polyethylene film as a starting membrane, the cation exchange membranes were prepared by chlorosulfonation reaction under irradiation ultraviolet. The PE-16(polyethylene of 16 ㎛ thickness) as a separator of all vanadium redox-flow battery which was obtained by the chlorosulfonation for 60 minutes under the irradiation of UV intensity 22,000 lux, showed the best result with electrical areal resistivity 0.61 Ω·㎠, transport number 0.97 and ion exchange capacity 0.8752.

지르코니아 코팅 지지체를 이용한 수소분리막

최호상,유철휘,황갑진 한국막학회 2010 멤브레인 Vol.20 No.3

IS (요오드-황)프로세스의 HI 분해반응 공정에서의 적용을 목적으로 지르코니아 코팅 지지체를 이용하여 CVD법에 의해 수소분리막을 제작하였으며, 분리막으로서의 가능성을 평가하였다. 제작한 막의 형상 및 Si의 분포를 파악하기 위해 SEM 및 EPMA를 이용하여 분석하였다. 지르코니아를 코팅한 지지체를 이용하여 제작한 막에 Zr-Si-O층이 존재한다는 것을 알 수 있었다. 제작한 막의 수소와 질소가스의 단일 성분 투과속도를 300~600℃에서 측정하였다. 600℃에서 Z-1막에서의 수소투과속도는 1 x 10 -7 mol·Pa -1·m -2·s -1를 나타냈다. 질소에 대한 수소의 선택성은 Z-1 막에서 5.0, Z-2막에서 5.75를 나타냈다. The hydrogen permselective membrane were prepared by chemical vapor deposition (CVD) aiming at the applications to hydrogen iodide decomposition in the thermochemical IS process, and it was evaluated for the possibility as a separation membrane. An electron probe X-ray microanalyzer (EPMA) and SEM picture were used to analyze the morphology and structure of the prepared membranes. It was confirmed that Zr-Si-O layer exist in the surface of the prepared membrane using zirconia coated support. Single-component permeance to H2 and N2 were measured at 300~600℃. Hydrogen permeance through the Z-1 membrane at a permeation temperature of 600℃ was about 1 x 10 -7 mol·Pa -1·m -2·s -1. The selectivities of H2/N2 at 600℃ were 5.0 and 5.75 for Z-1 and Z-2 membrane, respectively.

Bipolar막에서 전류/전압곡선에 미치는 중간계면 성분의 영향

정세일,유철휘,황용구,강안수 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.4

Bipolar막을 이용한 전기투석공정은 에너지 효율이 높고, 매우 경제적이며 다양한 용도를 갖고 있다. 이 공정은 성능이 좋은 bipolar막의 제조 및 공정의 개선으로 폐수처리, 고가의 순수한 유기 및 무기산의 제조 등에 그 적용 범위가 확대되고 있는 추세이다. 그러나, bipolar막을 이용한 전기투석 공정은 bipolar막이 매우 고가로 경제성과 bipolar막을 이용한 공정을 최적화하기에는 현재 water-splitting 메커니즘에 대한 이해가 부족하다는 문제점이 있으며, 이에 대한 연구와 막의 개발이 시급한 형편이다. 본 연구에서는 polysulfone을 poly(phenylene sulfide sulfone)와 공중합시켜 block copolymer를 제조하였고 sulfonation과 amination을 통하여 각각 양/음이온교환막을 제조하였다. 양/음이온 교환막 제조 시 전기화학적 특성과 물리적 특성을 고려하여 최적 제막조건을 확립하였고, 이를 적층하여 bipolar막을 제조하였다. Bipolar막의 최적조건을 찾기 위해 중간계면 성분의 변화에 따른 전류/전압 곡선을 측정하였고, 전기투석의 응용으로서 pH 변화를 측정하여 우수한 bipolar막을 제조하였다. 중간계면에 변화를 주어 bipolar막 제조 시 아민기가 도입된 biolar막의 성능이 좋았고, 특히 3차 아민기가 도입된 bipolar막이 가장 우수한 water-splitting 특성을 보였으며, 100mA/㎠의 전류밀도에서 2.4V의 막전위를 보였다. Electrodialysis process with bipolar membrane is economically very attractive and has a multitude of interesting potential applications. Although the process expand applications such as waste water treatment, and recovery of pure organic and inorganic acids with the efficient bipolar membrane, the large scale utilization of bipolar membrane is still limited by unsatisfactory membrane properties and by a lack of application knowhow. In this study, the block copolymer(BPSf) was prepared by copolymerization of polysulfone(PSf) and poly(phenylene sulfide sulfone)(PPSS). The cation exchange membranes were prepared by the sulfonation of BPSf with chlorosulfonic acid and the anion exchange membranes were prepared by the chloromethylation by chloromethyl ether and the amination by triethyl amine. The bipolar membranes were fabricated by stacking anion exchange membrane over cation one with the conditions of good electrochemical characteristics and physical properties. The influence of intermediate layer components on the bipolar membrane properties such as current-voltage curve and pH was investigated, and the components were varied by pasting non-woven cloth, various polymers, and amine groups. Among the various bipolar membranes, the membrances prepared by tertiary amine group exhibited the best water-splitting effect and 2.4 V of membrane potential at 100 mA/㎠ of current density.