Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Cathode Porosity of Mixed Conducting (La0.6Sr0.4Co0.2Fe0.8O3) on the Power Generating Characteristics of Anode Supported SOFCs

혼합전도체 LSCF(La0.6Sr0.4Co0.2Fe0.8O3) 양극의 기공률에 따른 음극지지형 단전지의 출력특성 평가

  • 윤중철 (고려대학교 재료공학과, 한국과학기술연구원 나노재료연구센터) ;
  • 김우식 (한국과학기술연구원 나노재료연구센터) ;
  • 김형철 (한국과학기술연구원 나노재료연구센터) ;
  • 이종호 (한국과학기술연구원 나노재료연구센터) ;
  • 김주선 (한국과학기술연구원 나노재료연구센터) ;
  • 이해원 (한국과학기술연구원 나노재료연구센터) ;
  • 김병호 (고려대학교 재료공학과)
  • Published : 2005.04.01
Download PDF
⟨ Previous Next ⟩

Abstract

We analyzed the unit cell performance against the cathode porosity, which is supposed to be closely related with active sites for the cathode reaction. In order to fabricate the unit cells with different porosity in the cathode layer we changed the mixing ratio of fine and coarse LSCF cathode powders. The final porosity of each cathode layer was 14, 23, 27, $39\%$ respectively. According to the electrochemical analysis of unit cell performance via DC current interruption and AC impedance method, the electrodic polarization resistance was diminished as the cathode porosity increased. The decrease of polarization resistance was attributed due to the increase of active reaction sites and the enhancement of overall unit cell performance could be explained in the same line.

단전지의 성능을 혼합전도체인 LSCF 양극의 미세구조, 특히 전극반응에 필요한 표면적의 양과 연관되는 앙극의 기공률의 변화에 따라 평가하였다. 기공률이 서로 다른 양극을 제조하기 위해 미세한 양극분말과 조대한 양극분말의 혼합비를 달리하여 양극을 제조한 결과 양극의 기공률을 각각 14, 23, 27, $39\%$로 얻을 수 있었다. 양극 기공률이 서로 다른 4종류의 단전지에 대한 직류 전류차단법과 교류임피던스법을 이용한 전기화학적 평가 결과 전극에서의 분극은 양극의 기공률이 증가할수록 감소하는 결과를 얻었다. 이러한 분극특성은 양극의 기공률이 증가하며 전극반응에 필요한 활성면적이 증가했기 때문으로 추론되며 이러한 이유로 단전지의 성능 또한 양극의 기공률이 증가하면서 향상되는 것으로 나타났다.

Keywords

References

  1. N. Q. Minh, ' Ceramic Fuel Cell,' J. Am. Ceram. Soc., 76 [3] 563-88 (1993) https://doi.org/10.1111/j.1151-2916.1993.tb03645.x
  2. J. Will, A. Mitterdorfer, C. Kleinlogel, D. Perednis, and L. J. Gauckler, ' Fabrication of Thin Electrolytes for Second-generation Solid Oxide Fuel Cells,' Solid State Ionics, 131 79-96 (2000) https://doi.org/10.1016/S0167-2738(00)00624-X
  3. J. D. Kim, G. D. Kim, J. W. Moon, Y. I. Park, W. H. Lee, K. Kobayashi, M. Nagai, and C. E. Kim, ' Characterization of LSM-YSZ Composite Electrode by AC Impedance Spectroscopy,' Solid State Ionics, 143 379-89 (2001) https://doi.org/10.1016/S0167-2738(01)00877-3
  4. H. C. Yu and K. Z. Fung, ' Electrode Properties of $L_{1-x}Sr_{x}CuO_{2.5-\delta}$ as New Cathode Materials for Intermediate-Temperature SOFCs,' J. of Power Sources, 133 162-68 (2004) https://doi.org/10.1016/j.jpowsour.2004.02.002
  5. B. C. H. Steele, ' Survey of Materials Selection for Ceramic Fuel Cells; II. Cathodes and Anodes,' Solid State Ionics, 86-88 1233-34 (1996)
  6. J. V. Herle, A. J. McEvoy, and K. R. Thampi, ' A Study of the $La_{1-x}Sr_{x}MnO_{3}$ Oxygen Cathode,' Electrochimica Acta, 41 [9] 1447-54 (1996) https://doi.org/10.1016/0013-4686(95)00393-2
  7. T. Kenjo and M. Nishiya, ' $LaNnO_{3}$ Air Cathodes Containing $ZrO_{2}$ Electrolyte for High Temperature Solid Oxide Fuel Cells,' Solid State Ionics, 57 295-302 (1992) https://doi.org/10.1016/0167-2738(92)90161-H
  8. S. B. Adler, ' Mechanism and Kinetics of Oxygen Reduction on Porous $L_{1-x}Sr_{x}CuO_{3-\delta}$ Electrodes,' Solid State Ionics, 111 125-34 (1998) https://doi.org/10.1016/S0167-2738(98)00179-9
  9. C. Xia, W. Rauch, F. Chen, and M. Lia, ' $Sm_{0.5}Sr_{0.5}CoO$ Cathodes for Low Temperature SOFCs,' Solid State Ionics, 149 11-9 (2002) https://doi.org/10.1016/S0167-2738(02)00131-5
  10. A. Esquirol, N. P. Brandon, J. A. Kilner, and M. Mogensen, ' Electrochemical Characterization of $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3}$ Cathodes for Intermediate-Temperature SOFCs,' J. Electrochemical Soc., 151 A1847-A55 (2004) https://doi.org/10.1149/1.1799391
  11. J. Larminie and A. Dicks, ' Fuel Cell Systems Explained,' pp. 1-59, Plenum Press, New York, 1993
  12. M. C. Williams, ' Fuel Cell Handbook,' Sixth Edition, 37-52, EG&G Technical Services. Inc., West Virginia, 2002
  13. F. Zhao and A. V. Virkar, ' Dependence of Polarization in Anode-Supported Solid Oxide Fuel Cells on various Cell Parameters,' J. Power Sources, In press, Corrected proof
  14. L. W. Tai, M. M. Nasrallah, H. U. Anderson, D. M. Sparlin, and S. R. Sehlin, 'Structure and Electrical Properties of $La_{1-x}Sr_{x}Co_{1-y}Fe_{y}O_{3}$. Part 1. The System $La_{0.8}Sr_{0.2}Co_{1-y}Fe_{y}O_{3}$,' Solid State Ionics, 76 259-71 (1995) https://doi.org/10.1016/0167-2738(94)00244-M
  15. F. Zhao and A. V. Virkar, ' Dependence of Polarization in Anode-Supported Solid Oxide Fuel Cells on various Cell Parameters,' J. Power Sources, 141 79-95 (2005) https://doi.org/10.1016/j.jpowsour.2004.08.057
  16. K. R. Lee, S. H. Choi, J. Kim, H. W. Lee, and J. H. Lee, ' Viable Image Analyzing Method to Characterize the Microstructure and the Properties of the Ni/YSZ Cermet Anode of SOFC,' J. Power Source, 140 226-34 (2005) https://doi.org/10.1016/j.jpowsour.2004.06.031