DOI QR코드

DOI QR Code

장기운전에 의한 직접메탄올 연료전지 스택의 성능 열화 분석

Diagnosis of Performance Degradation of Direct Methanol Fuel Cell Stack after Long-Term Operation

  • 김상경 (한국에너지기술연구원 연료전지연구단) ;
  • 현민수 ((주) LS산전 선행기술연구소) ;
  • 이병록 (한국에너지기술연구원 연료전지연구단) ;
  • 정두환 (한국에너지기술연구원 연료전지연구단) ;
  • 백동현 (한국에너지기술연구원 연료전지연구단) ;
  • 임성엽 (한국에너지기술연구원 연료전지연구단)
  • Kim, Sang-Kyung (Fuel Cell Research Center, Korea Institute of Energy Research) ;
  • Hyun, Min-Soo (Advanced Technology R&D Center, LS Industrial Systems Co., Ltd.) ;
  • Lee, Byung-Rok (Fuel Cell Research Center, Korea Institute of Energy Research) ;
  • Jung, Doo-Hwan (Fuel Cell Research Center, Korea Institute of Energy Research) ;
  • Peck, Dong-Hyun (Fuel Cell Research Center, Korea Institute of Energy Research) ;
  • Lim, Seong-Yop (Fuel Cell Research Center, Korea Institute of Energy Research)
  • 발행 : 2011.12.01

초록

50 $cm^2$의 활성면적을 가진 셀을 이용하여 5-셀 DMFC 스택을 제작하고 4 A의 부하로 4,000 시간 운전한 후 성능감소 및 성능 감소 원인을 분석하였다. 4,000 시간 운전 후 10 A에서 스택의 전력 밀도가 28.7% 감소하였으며 다섯개의 셀 중 두 개는 거의 성능저하가 일어나지 않았고 두 개는 약 40%의 성능 저하, 한 개는 약 60%의 성능 저하를 보였으며 각 셀별 성능저하의 정도의 차이는 스택 내에서의 위치와 상관관계가 없었다. 스택 내의 다섯 셀 중 가장 성능감소가 심하였던 셀의 경우 연료극 촉매층의 Pt 입자 크기가 증가하였으며 연료가 들어가는 쪽의 Pt 입자의 크기 증가가 더 심하였다. 그러나 4,000 시간 장기운전 후 공기극 촉매층에서는 Pt 입자 크기의 변화는 거의 없었다. 스택 내의 모든 셀에서 4,000 시간 운전 후 연료극 촉매에서 공기극 촉매로의 루테늄의 크로스오버가 SEM-EDX로 관찰되었으며 특히 성능감소가 심하였던 셀의 경우 공기극 촉매층에서 Ru/Pt의 비율이 가장 컸다.

5-cell DMFC stack was fabricated and operated with the load of 4 A for 4000 hrs. After 4000 hrs operation peak power density of the stack reduced by 27.3%. Two of the five cells did now show performance degradation, the performance of other two was reduced by 40% and the performance of the other decreased by 60%. The amount of performance degradation of each cell by long-term operation did not correlate with the position in the stack. Platinum particle size in the anode catalyst layer of the MEA with the strongest degradation increased and the increase was severer on the position of methanol inlet than on the position of methanol outlet. However, platinum particle size in the cathode catalyst layers did not changed for all the MEA'. Ruthenium crossover from the anode catalyst layer to the cathode catalyst layer through the membrane was observed after 4,000 hrs operation by SEM-EDX and it occurred for all MEA' regardless of the degree of performance degradation. Atomic ratio of ruthenium to platinum in the cathode catalyst layer was the highest in the MEA with the strongest performance degradation.

키워드

참고문헌

  1. Vielstich, W., Lamm, A. and Gasteiger, H. A.(Ed), Handbook of Fuel Cells Vol. 1, 1st ed, Wiley, Chichester(2003).
  2. Larminie, J. and Dicks, A., Fuel Cell System Explained, 2nd ed., Wiley, Chichester(2003).
  3. O'hayre, R., Cha, S.-W., Colella, W. and Prinz, F. B., Fuel Cell Fundamentals, 2nd ed, Wiley, New York(2009).
  4. Chen, Z., Qiu, X., Lu, B., Zhang, S., Zhu, W. and Chen, L., "Synthesis of Hydrous Ruthenium Oxide Supported Platinum Catalysts for Direct Methanol Fuel Cells," Electrochem. Comm., 7(6), 593-596(2005). https://doi.org/10.1016/j.elecom.2005.04.002
  5. Tsiouvaras, N., Martnez-Huerta, M. V., Paschos, O., Stimming, U., Fierro, J. L. G. and Pea, M. A., "PtRuMo/C Catalysts for Direct Methanol Fuel Cells: Effect of the Pretreatment on the Structural Characteristics and Methanol Electrooxidation", Int. J. Hydr. Energ., 35(20), 11478-11488(2010). https://doi.org/10.1016/j.ijhydene.2010.06.053
  6. Chen, S., Ye, F. and Lin, W., "Effect of Operating Conditions on the Performance of a Direct Methanol Fuel Cell with PtRuMo/ CNTs as Anode Catalyst," Int. J. Hydr. Energ., 35(15), 8225-8233 (2010). https://doi.org/10.1016/j.ijhydene.2009.12.085
  7. Kawaguchi, T., Sugimoto, W., Murakami, Y. and Takasu, Y., "Particle Growth Behavior of Carbon-supported Pt, Ru, PtRu Catalysts Prepared by an Impregnation Reductive-Pyrolysis Method for Direct Methanol Fuel Cell Anodes," J. Catal., 229(1), 176-184(2005). https://doi.org/10.1016/j.jcat.2004.10.020
  8. Hsu, N.-T., Chien, C.-C. and Jeng, K.-T., "Characterization and Enhancement of Carbon Nanotube-supported PtRu Electrocatalyst for Direct Methanol Fuel Cell Applications," Appl. Catal. B: Environ., 84(1-2), 196-203(2008). https://doi.org/10.1016/j.apcatb.2008.03.018
  9. Demarconnay, L., Coutanceau, C. and Lger, J.-M., "Electroreduction of dioxygen (ORR) in Alkaline Medium on Ag/C and Pt/C Nanostructured Catalysts - Effect of the Presence of Methanol," Electrochimica Acta, 49(25), 4513-4521(2004). https://doi.org/10.1016/j.electacta.2004.05.009
  10. Piela, B., Olson, T. S., Atanassov, P. and Zelenay, P., "Highly Methanol- tolerant Non-precious Metal Cathode Catalysts for Direct Methanol Fuel Cell," Electrochimica Acta, 55(26), 7615-7621(2010). https://doi.org/10.1016/j.electacta.2009.11.085
  11. Jeyabharathi, C., Venkateshkumar, P., Mathiyarasu, J. and Phani, K. L. N., "Platinum-tin Bimetallic Nanoparticles for Methanol Tolerant Oxygen-reduction Activity," Electrochimica Acta, 54(2), 448- 454(2008). https://doi.org/10.1016/j.electacta.2008.07.053
  12. Papageorgopoulos, D. C., Liu, F. and Conrad, O., "A Study of $Rh_{x}Se_{y}$/C and $RuSe_{x}$/C as Methanol-tolerant Oxygen Reduction Catalysts for Mixed-reactant Fuel Cell Applications, " Electrochimica Acta, 52(15), 4982-4986(2007). https://doi.org/10.1016/j.electacta.2007.01.076
  13. Wang, J., Zhao, C., Zhang, G., Zhang, Y., Ni, J., Ma, W. and Na, H., "Novel Covalent-ionically Cross-linked Membranes with Extremely Low Water Swelling and Methanol Crossover for Direct Methanol Fuel Cell Applications," J. Membr. Sci., 363(1-2), 112-119(2010). https://doi.org/10.1016/j.memsci.2010.07.022
  14. Yamauchi, A., Ito, T. and Yamaguchi, T., "Low Methanol Crossover and High Performance of DMFCs Achieved with a Pore-filling Polymer Electrolyte Membrane," J. Power Sources, 174(1), 170- 175(2007). https://doi.org/10.1016/j.jpowsour.2007.08.081
  15. Li, W. and Manthiram, A., "Sulfonated poly(arylene ether sulfone) as a Methanol-barrier Layer in Multilayer Membranes for Direct Methanol Fuel Cells," J. Power Sources, 195(4), 962-968(2010). https://doi.org/10.1016/j.jpowsour.2009.08.096
  16. Kim, D., Lee, J., Lim, T.-H., Oh, I.-H. and Ha, H. Y., "Operational Characteristics of a 50 W DMFC Stack," J. Power Sources, 155(2), 203-212(2006). https://doi.org/10.1016/j.jpowsour.2005.04.033
  17. Park, Y.-C., Peck, D.-H., Kim, S.-K., Dong, S.-K., Lim, S., Jung D.-H., Jang, J.-J. and Lee D.-Y., "Operating Characteristics and Performance Stability of 5W Class Direct Methanol Fuel Cell Stacks with Different Cathode Flow Patterns", Int. J. Hydr. Energ., 36(2), 1853-1861(2011). https://doi.org/10.1016/j.ijhydene.2010.02.018
  18. Park, Y.-C., Peck, D.-H., Kim, S.-K., Lim, S., Lee, D.-Y., Ji, H. and Jung, D.-H., "Operation Characteristics of Portable Direct Methanol Fuel Cell Stack at Sub-zero Temperatures Using Hydrocarbon Membrane and High Concentration Methanol," Electrochimica Acta, 55(15), 4512-4518(2010). https://doi.org/10.1016/j.electacta.2010.02.096
  19. Wang, Z. H. and Wang, C. Y., "Mathematical Modeling of Liquid- feed Direct Methanol Fuel Cellls", J. Electrochem. Soc., 150(4), A508-A519(2003). https://doi.org/10.1149/1.1559061