http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Intermediate-temperature solid oxide electrolysis cell with bi-layered electrolyte structure
( Asif Mahmood ),( Saira Bano ),( Ji Haeng Yu ),이규호 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1
A Ni-GDC supported solid oxide electrolysis cell with bi-layered ScSZ/GDC electrolyte and LSCF oxygen electrode was developed for intermediate-temperature steam and CO<sub>2</sub> electrolysis. The OCV of bi-layered electrolyte cell was significantly improved as compared to cell with single-layered GDC electrolyte structure, but at the cost of an increase in electrolyte resistance (R<sub>e</sub>) and electrode polarization resistance (R<sub>p</sub>). The formation of (Zr, Ce)O<sub>2</sub> solid solution at the interfaces of ScSZ interlayer during co-sintering caused the increase in Re and Rp. Unlike single-layered GDC electrolyte cell, the bi-layered electrolyte cell did not show a noticeable internal electrical shorting under SOEC conditions and thus exhibited a good electrolysis performance. However, the cell stability test revealed a performance decay at the rate of 5 mV/h, when operated in co-electrolysis (H<sub>2</sub>:steam:CO<sub>2</sub> = 20:40:40 vol.%) under -0.5A/㎠ at 650°C over 100h.
최훈,조구영,차석원 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.1 No.2
In the present paper, we fabricated and tested anode-supported solid oxide fuelcell(SOFC) with gadolinium-doped(GDC) and yttriastabilized zirconia (YSZ) electrolyte. The bilayer electrolyte thin film, consisting of a 8 μm thick YSZ layer and a 40 μm thick GDC layer, was prepared by a simple dry-pressing with simple spray coating process which is cost-effective method. The two electrolyte layers were sintered 1400oC together, and no crack and delamination at the interface were observed. An open-circuit voltage of 0.91 V and a maximum power density of over 218 mW/cm2 were measured with 3% H2O-H2 as fuel and air as oxidant at 600oC. The result shows that the electronic conductivity of GDC electrolyte was blocked by the thin YSZ electrolyte functional layer.
Jeong, Seung Jin,Kwak, No Woo,Byeon, Pilgyu,Chung, Sung-Yoon,Jung, WooChul American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.7
<P>Stabilized Bi2O3 has gained a considerable amount of attention as a solid electrolyte material for low temperature solid oxide fuel cells due to its superior oxygen ion conductivity at the temperature of relevance (<= 500 degrees C). Despite many research efforts to measure the transport properties of stabilized Bi2O3, the effects of grain boundaries on the electrical conductivity have rarely been reported and their results are even controversial. Here, we attempt quantitatively to assess the grain boundary contribution out of the total ionic conductivity at elevated temperatures (350-500 degrees C) by fabricating epitaxial and nano-polycrystalline thin films of yttrium-stabilized Bi2O3. Surprisingly, both epitaxial and polycrystalline films show nearly identical levels of ionic conductivity, as measured by alternating current impedance spectroscopy and this is the case despite the fact that the polyfilm possesses nanosized columnar grains and thus an extremely high density of the grain boundaries. The highly conductive nature of grain boundaries in stabilized Bi2O3 is discussed in terms of the clean and chemically uniform grain boundary without segregates, and the implications for device application are suggested.</P>
Han, Hyeuk Jin,Kim, Tae Wan,Kim, Seongwan,Oh, Soomin,Park, Chong-Ook Elsevier Sequoia 2017 Sensors and actuators. B Chemical Vol.248 No.-
<P><B>Abstract</B></P> <P>Solid-state bi-electrolyte carbon dioxide sensors with an yttira stabilized zirconia (YSZ) and sodium beta alumina (NBA) heterojunction were fabricated using the tape casting method to measure CO<SUB>2</SUB> concentrations in the air. The enhanced interface between NBA, expressed by (1+x) Na<SUB>2</SUB>O·11 A1<SUB>2</SUB>O<SUB>3</SUB> and YSZ was made by the liquid phase sintering method while varying the ratio of Na<SUB>2</SUB>O/Al<SUB>2</SUB>O<SUB>3</SUB> from x=0 to x=0.6. YSZ/Pt electrode was used as an air reference, maintaining a constant oxygen concentration of 21%, and Na<SUB>2</SUB>CO<SUB>3</SUB> was used as a CO<SUB>2</SUB> sensing electrode. The responses of the sensors to various concentrations of CO<SUB>2</SUB> were evaluated at temperatures ranging from 550°C to 650°C. The electric potential difference of the sensors exhibited Nernstian behavior with sensitivity greater than 99% of the theoretical value at 650°C. The activity of Na<SUB>2</SUB>O at the bi-electrolyte junction remained constant, showing invariance with the CO<SUB>2</SUB> concentrations tested. The time for the initial stabilization was as short as 66s.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A bi-electrolyte carbon dioxide sensor was fabricated using a tape casting method. </LI> <LI> The sensor gave sensitive responses to carbon dioxide at 550–650°C. </LI> <LI> The carbon dioxide sensing behavior of the sensor obeyed the Nernst equation. </LI> <LI> The response time for the initial stabilization was as short as 66s. </LI> </UL> </P>
중·저온 영역 SOFC용 고체 전해질로의 응용을 위한 Bi가 첨가된 아파타이트형 란타늄 실리케이트의 전기적 특성
김대영,정광호,이성갑,Kim, Dae-Young,Jeong, Gwang-Ho,Lee, Sung-Gap 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.6
$La_{7.33}Bi_2(SiO_4)_6O_2$ specimens were fabricated by standard solid-state synthesis route for solid oxide electrolytes. The calcined powders exhibited uniform particles with a mean particle size of about $28{\mu}m$. The room-temperature structure of $La_{7.33}Bi_2(SiO_4)_6O_2$ specimens was analyzed as hexagonal, space group P63 or P63/m, and the unit cell volume increased with increase a sintering temperature. The specimens sintered at $1,175^{\circ}C$ showed X-ray patterns of homogeneous apatite single phase without the second phase such as $La_2Si_2O_7$ and $La_2SiO_5$. The specimen sintered at $1,175^{\circ}C$ showed the maximum sintered density of 5.49 $g/cm^3$. Increasing the sintering temperature, total conductivities increased, activation energy decreased and the values were $1.98{\times}10^{-5}Scm-1$ and 1.23 eV, respectively.
초청 총설 : 고출력·고에너지 밀도의 아연금속-공기전지
박동원 ( Dong Won Park ),김진원 ( Jin Won Kim ),이재광 ( Jae Kwang Lee ),이재영 ( Jae Young Lee ) 한국공업화학회 2012 공업화학 Vol.23 No.4
아연금속-공기전지는 기존의 이차전지보다 높은 중량당 에너지 밀도, 낮은 제조단가를 가짐과 동시에 소재적으로 친 환경적이다. 소형 및 중대형 전력 저장 시스템, 전기자동차, 스마트 휴대기기의 상용화에 있어 최우선시 되고 있는 것은 배터리의 충·방전 능이다. 따라서 환원 촉매의 높은 과전압, 산화 전극의 불안정성 및 비가역성, 액체 전해질 사용에 따른 여러 문제점을 해결하여야 한다. 본 총설에서는 공기극 막의 손상 방지 기술, 아연금속 전극의 구조 개선을 통한 충전효율 저하 방지 기술, 부반응 및 부동태화를 막기 위한 하이브리드 전해질 도입 등의 최근 기술적 이슈와 연구동향을 소개하고자 한다. Zn-Air energy storage cell is an attractive type of batteries due to its theoretical gravimetric energy density, cost-effective structure and environmental-friendly characteristics. The chargeability is the most critical in various industrial applications such as smart portable device, electric vehicle, and power storage system. Thus, it is necessary to reduce large overpotential of oxygen reduction/evolution reaction, the irreversibility of Zn anode, and carbonation in alkaline electrolyte. In this review, we try to introduce recent studies and developments of bi-functional air cathode, enhanced charge efficiency via modification of Zn anode structure, and blocking side reactions applying hybrid organic-aqueous electrolyte for high power density rechargeable Zn-Air energy storage cells.
박현석(Hyun-Seok Park),강선두(Seun-Doo Kang),민태홍(Tae-Hong Min),정귀성(Kwi-Seong Jeong),원충연(Chung-Yuen Won) 한국조명·전기설비학회 2018 조명·전기설비학회논문지 Vol.32 No.4
Researches to control water content of Polymer Electrolyte Membrane(PEM) of fuel cell are actively performed for increasing performance & durability of fuel cell. This research to control water content focused on detection of PEM impedance. In this paper, the detection unit of fuel cell impedance based on AC current impedance method is proposed. Bi-directional DC/DC converter is designed to generate AC in detection unit of fuel cell impedance. The validity of proposed detection unit of fuel cell impedance is verified by test results in the fuel cell stack and FCEV.
Effect of a Series Connection of a Bi-Electrolyte Hydrogen Sensor in a Leak Detector
( Hyeuk Jin Han ),( Chong Ook Park ),( Young Kyu Hong ),( Jong Suk Kim ),( Jeong Woo Yang ),( Yoon Seo Kim ) 한국센서학회 2015 센서학회지 Vol.24 No.1
Conventional leak detectors are widely based on helium gas sensors. However, the usage of hydrogen sensors in leak detectors has increased because of the high prices of helium leak detectors and the dearth in the supply of helium gas. In this study, a hydrogen leak detector was developed using solid-state hydrogen sensors. The hydrogen sensors are based on Park.Rapp probes with heterojunctions made by oxygen-ion conducting Yttria-stabilized zirconia and proton-conducting In-doped CaZrO3. The hydrogen sensors were used for determining the potential difference between air and air balanced 5 ppm of H2. Even though the Park.Rapp probe shows an excellent selectivity for hydrogen, the sensitivity of the sensor was low because of the low concentration of hydrogen, and the oxygen on the surface of the sensor. In order to increase the sensitivity of the sensor, the sensors were connected in series by Pt wires to increase the potential difference. The sensors were tested at temperatures ranging from 500.600oC.