연료극 지지체식 원통형 고체산화물 연료전지의 성능 특성

송락현,송근숙,Song Rak-Hyun,Song Keun-Suk 한국재료학회 2004 한국재료학회지 Vol.14 No.5

To improve the conventional cathode-supported tubular solid oxide fuel cell (SOFC) from the viewpoint of low cell power density, expensive fabrication process and high operation temperature, the anode-supported tubular solid oxide fuel cell was investigated. The anode tube of Ni-8mol% $Y_2$O$_3$-stabilized $ZrO_2$ (8YSZ) was manufactured by extrusion process, and, the electrolyte of 8YSZ and the multi-layered cathode of $LaSrMnO_3$(LSM)ILSM-YSZ composite/$LaSrCoFeO_3$ were coated on the surface of the anode tube by slurry dip coating process, subsequently. Their cell performances were examined under gases of humidified hydrogen with 3% water and air. In the thermal cycle condition of heating and cooling rates with $3.33^{\circ}C$/min, the anode-supported tubular cell showed an excellent resistance as compared with the electrolyte-supported planar cell. The optimum hydrogen flow rate was evaluated and the air preheating increased the cell performance due to the increased gas temperature inside the cell. In long-term stability test, the single cell indicated a stable performance of 300 mA/$\textrm{cm}^2$ at 0.85 V for 255 hr.

교류 임피던스법에 의한 인산형 연료전지의 산소전극 특성 연구

송락현,김창수,신동열,Song Rak-Hyun,Kim Chang-Soo,Shin Dong-Ryul 한국전기화학회 2000 한국전기화학회지 Vol.3 No.4

교류 임피던스법을 사용하여 온도, 부하전위 및 전극내 테프론 함량에 따른 인산형 연료전지의 산소전극 반응의 특성을 연구하였다. $105wt.\%$ 인산에서 산소 전극의 임피던스 거동은 전극 계면 저항, 전극 계면 캐패스턴스 및 전해질 저항으로 이루어진 간단히 회로로 특징지어지고, 이것으로부터 구한 인산의 전기전도도는 $130\~190^{\circ}C$의 온도범위에서 0.31-0.47 S/cm 로 나타났다. 부하전위와 온도가 증가함에 따라 산소극의 계면저항은 감소하였으나 산소극의 계면 캐패스턴스는 증가하였으며, 이것은 산소극의 반응속도와 전극의 계면 임피던스가 직접적인 관계를 가진다는 것을 의미한다. 테프론 함량에 따른 인산형 연료전지 단전지의 성능을 조사하여 임피던스 측정결과와 비교하였으며, $40wt.\%$에서 최대 성능을 나타내었고, 이것은 산소극의 계면 임피던스 값이 최적 상태를 나타내었기 때문인 것으로 판단되며, 이러한 결과들이 전극의 3상계면 상태와 연관지어 토의되었다. Electrochemical properties of the oxygen electrode in phosphoric acid fuel cell have been studied using AC impedance method as a function of applied potential, operating temperature and teflon content in the electrode. The oxygen electrode reaction in the $105wt.\%$ phosphoric acid is characterized by a parallel resistive component, $R_p$ and a capacitive component, $C_p$ with serial electrolyte resistance, $R_s$. The conductivity of the phosphoric acid is found to be 0.31-0.47 S/cm in the range of $130\;to\;190^{\circ}C$ from the measured impedance. The increase of applied potential and temperature produced the decreased RP and the increased $C_p$, which means the increase of the oxygen electrode reaction rate. The single cells with the cathode of various teflon contents were tested, and the cathode with $40wt.\%$ teflon showed good performance, which is considered to be related to an optimized impedance behavior.

공소결법에 의해 제조된 지지체식 평판형 고체산화물 연료전지 성능 특성

송락현,Song, Rak-Hyun 한국재료학회 2003 한국재료학회지 Vol.13 No.3

The co-firing processes for the supported type planar solid oxide fuel cell were investigated. A flat cell of $7.7${\times}$10.8\textrm{cm}^2$ was fabricated successfully by the co-firing process, in which green films were co-sintered in the forms of two layers of anode/electrolyte or of three layers of anode/electrolyte/cathode with gas distributor. A co-fired cell of two layers yielded a power of 200 ㎽/$\textrm{cm}^2$ at 608 ㎷. Its performance loss was mainly due to iR drop in the anodic gas distributor, which was attributed to poor contact between anodic gas distributor and current collector. The performance in the co-fired cell of three layers was much lower than that of two layers, which resulted from the large iR drop and activation overvoltage at the cathodic side. In the co-fired cell of two layers, the impedance analysis indicated that the performance decay during cell operation is due to both anode overvoltage and iR drop at anode side. Also the electrode reaction of the co-fired two layers' cell is considered to be controlled by activation overvoltage within the low current of 50 ㎃.

연료극 지지체식 고체산화물 연료전지용 고성능 공기극 제조 및 특성 연구

송락현,Song, Rak-Hyun 한국전기화학회 2005 한국전기화학회지 Vol.8 No.2

고체산화물 연료전지의 작동온도를 낮추고 셀의 출력 밀도를 향상시키기 위해 연료극 지지체식 셀을 제조하고 공기극의 구조를 개선시켜 그 특성을 조사 분석하였다. 셀 제조는 습식법에 의해 이루어졌으며, 제조된 연료극 지지체상에 전해질을 코팅하고 최종적으로 공기극을 코팅하였다. 제조된 셀은 $8mol\%\;V_2O_3$로 안정화된 $ZrO_2(YSZ)$ 전해질 층 및 Ni/YSZ 연료극 지지체로 이루어졌으며, 공기극은 $(La_{0.85}Sr_{0.15})_{0.9}MnO_{3-x}(LSM),\;LSM/YSZ(LY)$ 복합체, $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3{LSCF)$를 두층 또는 3층으로 두께를 변화시키면서 코팅하였다 임피던스로 전기화학적 특성을 조사하였으며, $3\%$수분을 함유한 수소와 공기로 $800^{\circ}C$ 이하에서 단전지의 성능을 평가하였다 작동온도 $800^{\circ}C$에서, $LY\;9{\mu}m/LSM\;9{\mu}m/LSCF\;17{\mu}m$의 다층이 코팅된 전지가 $590mW/cm^2$로 가장 좋은 성능을 나타냈으며, $0.244{\Omega}cm^2$로 가장 작은 분극저항을 가졌다. 측정된 임피던스 결과, 공기극의 분극저항이 3층 코팅된 셀의 경우 가장 작게 나타났음을 확인하였으며, 이것은 LY복합전극에 의한 전극 계면 저항 감소뿐 만 아니라 LSCF에 의한 공기극의 산소환원 반응의 전하이동 저항이 감소하였기 때문인 것으로 해석된다. Anode-supported solid oxide fuel cell (SOFC) was investigated to increase the cell power density at intermediate temperature through control of the cathode structure. The anode-supported SOFC cell were fabricated by wet process, in which the electrolyte of $8mol\%\;Y_2O_3-stabilized\;ZrO_2 (YSZ)$ was coated on the surface of anode support of Ni/YSA and then the cathode was coated. The cathode has two- or three- layered structure composed of $(La_{0.85}Sr_{0.15})_{0.9}MnO_{3-x}(LSM),\;LSM/YS$ composite (LY), and $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3{LSCF)$ with different thickness. Their single cells with different cathode structures were characterized by measuring the cell performance and ac impedance in the temperature range of 600 to $800^{\circ}C$ in humidified hydrogen with $3\%$ water and air. The cell with $LY\;9{\mu}m/LSM\;9{\mu}m/LSCF\;17{\mu}m$ showed best performance of $590mW/cm^2$, which was attributed to low polarization resistance due to LY and to low interfacial resistance due to LSCF.

인산형 연료전지의 단위전지 운전 특성 연구

송락현,김창수,최병우,신동렬,최수현 ( Rak Hyun Song,Chang Soo Kim,Byung Woo Choi,Dong Ryul Shin,Soo Hyun Choi ) 한국화학공학회 1993 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.31 No.6

Operational characteristics of single cell in phosphoric acid fuel cell(PAFC) have been studied using oxygen gain and AC impedance methods. Also effect of reactant gas starvation on PAFC performance was examined. The single cell was operated for 4,500 hr at the average performance decay rate of 19.7 mV/1,000 hr. At the operation time below 1,000 hr the activation process was dominant over the cell electrode reaction and then the decreased cell performance is due mainly to an increased internal resistance of the cell and an increased interfacial resistance of the oxygen electrode. At the operation time above 2,000 hr, the oxygen gain was larger than a theoretical value of the activation-diffusion mixed process, which indicates that the cell decay at long run resulted from the slow diffusion process. In addition the hydrogen starvation showed more cell performance loss than the oxygen starvation due probably to carbon corrosion. These results were discussed as related to the oxygen electrode reaction at three phase boundary of the electrode and the degradation of the electrode components.

하이브리드 자동차의 EGR 밸브 오작동 시 엔진 성능에 미치는 영향

송락현(Rak Hyun Song),조행묵(Haeng Muk cho) 한국에너지학회 2015 에너지공학 Vol.24 No.3

인산형 연료전지 성능 특성에 미치는 전극 제조 조건의 영향

宋珞鉉(Rak-Hyun Song),金昌洙(Chang-Soo Kim),申東烈(Dong-Ryul Shin) 대한전기학회 1996 전기학회논문지 Vol.45 No.2

하이브리드자동차 고전압 시스템 인터록 회로 이상 시 미치는 영향에 관한 연구

송락현(Rak Hyun Song),조행묵(Haeng Muk Cho) 한국에너지학회 2015 에너지공학 Vol.24 No.3

원통형 고체산화물 연료전지 기술개발

송락현(Rak-Hyun Song) 한국유체기계학회 2001 유체기계 연구개발 발표회 논문집 Vol.- No.-

Solid Oxide Fuel Cells (SOFCs) have received considerable attention because of the advantages of high efficiency, low pollution, cogeneration application and excellent integration with simplified reformer.<br/> In this paper, we reported development of anode-tubular SOFC by wet process. For making tubular cell, Ni-cermet YSZ anode tube was fabricated using extrusion process, and YSZ electrolyte layer and LSM-YSZ composite, LSM, LSCF cathode layer were coated onto the anode supported tube using slurry dipping process and sintered by co-firing process. By using this tubular cell, we fabricated single cell consisted of the various cathode layers and 4 cell stack with an effective area of 75 ㎠ per single cell, and evaluated their performance characteristics.

인산형 연료전지의 발전성능에 미치는 반응기체 영향

宋珞鉉(Rak-Hyun Song),金昌洙(Chang-Soo Kim),申東烈(Dong-Ryul Shin) 대한전기학회 1996 전기학회논문지 Vol.45 No.3