Journal of the Korean Electrochemical Society (전기화학회지)

The Korean Electrochemical Society (한국전기화학회)
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Tubular Type Direct Methanol Fuel Cell for in situ NMR Diagnosis

In Situ NMR 진단용 원통형 직접 메탄올 연료전지

  • Joh, Han-Ik (Center for Fuel Cell Research, Korea Institute of Science and Technology) ;
  • Um, Myung-Sup (Center for Fuel Cell Research, Korea Institute of Science and Technology) ;
  • Han, Kee-Sung (Analysis Research Division Daegu Center, Korea Basic Science Institute) ;
  • Han, Oc-Hee (Analysis Research Division Daegu Center, Korea Basic Science Institute) ;
  • Ha, Heung-Yong (Center for Fuel Cell Research, Korea Institute of Science and Technology) ;
  • Kim, Soo-Kil (Center for Fuel Cell Research, Korea Institute of Science and Technology)
  • 조한익 (한국과학기술연구원 연료전지연구단) ;
  • 엄명섭 (한국과학기술연구원 연료전지연구단) ;
  • 한기성 (한국기초과학지원연구원 대구센터) ;
  • 한옥희 (한국기초과학지원연구원 대구센터) ;
  • 하흥용 (한국과학기술연구원 연료전지연구단) ;
  • 김수길 (한국과학기술연구원 연료전지연구단)
  • Published : 2009.11.30
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Abstract

This study is to develop a fuel cell system applicable to an in situ NMR (Nuclear magnetic resonance) diagnosis. The in situ NMR can be used in real time monitoring of various reactions occurring in the fuel cell, such as oxidation of fuel, reduction of oxygen, transport phenomena, and component degradation. The fuel cell for this purpose is, however, to be operated in a specifically designed tubular shape toroid cavity detector (TCD), which constrains the fuel cell to have a tubular shape. This may cause difficulties in effective mass transport of reactants/products and uniform distribution of assembly pressure. Therefore, a new flow field designed in a particular way is necessary to enhance the mass transport in the tubular fuel cell. In this study, a tubular-shaped close-type flow field made of non-magnetic material is developed. With this flow field, oxygen is effectively delivered to the cathode surface and the produced water is readily removed from the membrane-electrode assembly to prevent flooding. The resulting DMFC (direct methanol fuel cell) outperforms the open-type flow field and exhibits $36\;mW/cm^2$ even at room temperature.

본 연구는 연료전지 운전시 전극 촉매 및 전해질막 내에서 발생하는 연료 및 산화제의 산화/환원 반응 메커니즘, 이동현상, 구성품 열화현상 등을 핵자기 공명 (NMR, Nuclear Magnetic Resonance)을 이용하여 연료전지의 분해나 시료 채취 없이 제자리 (in situ) 분석할 수 있는 진단장치용 연료전지 개발에 관한 것이다. NMR에 사용되는 연료전지는 특수하게 제작된 TCD (Toroid Cavity Detector) 탐침 내부에서 작동하여야 하며, TCD 탐침이 가지는 기하학적 제한 요소들로 인해 일반적인 평판형 연료전지와 달리 원통형으로 제작된다. 이로 인해 반응물의 공급이나 생성물의 제거가 어려우며 누수 현상 및 불균일한 압력 분배가 발생하여 성능이 낮다. 따라서, in situ NMR 분석용 연료전지가 가지는 구조상의 특징인 원통형에 적합한 유로를 설계하고 제작하여 물질 전달 특성을 개선해야 할 필요성이 있다. 본 연구에서는 NMR 장비 내의 자기장에 영향을 미치지 않는 비자성 물질을 이용해 원 통형 공기극 유로를 개발하여, 산소의 공급 및 반응물의 제거를 원활하게 하였다. 또한, 체결 압력을막-전극 접합체에 균일하게 분배하여 누수 및 누액을 차단하였다. 이를 통해, 상온에서 약 $36mW/cm^2$의 우수한 성능을 나타내는 in situ NMR 진단용 직접 메탄올연료전지 시스템을 개발하였다.

Keywords

References

  1. H. -I. Joh, T. J. Ha, S. Y. Hwang, J. -H Kim, S. -H. Chae, J. H. Cho, J. Prabhuram, S. -K. Kim, T. -H. Lim, B. -K. Cho, J. -H. Oh, S. H. Moon, and H. Y. Ha, 'A direct methanol fuel cell system to power a humanoid robot' J. Power Sources, 195, 293 (2010) https://doi.org/10.1016/j.jpowsour.2009.07.014
  2. D. Kim, J. Lee, T.-H. Lim, I.-H. Oh, and H.Y. Ha, 'Operational characteristics of a 50 W DMFC stack' J. Power Sources, 155, 203 (2006) https://doi.org/10.1016/j.jpowsour.2005.04.033
  3. S. -K. Kim, E. S. Lee, Y. -Y. Kim, J. M. Kim, H. -I. Joh, and H. Y. Ha, 'Position-dependent cathode degradation of large scale membrane electrode assembly for direct methanol fuel cell' J. Korean Electrochem. Soc., 12, 148 (2009) https://doi.org/10.5229/JKES.2009.12.2.148
  4. J. -Y. Park, M. Aulice Scibioh, S. -K. Kim, H. -J. Kim, I. -H. Oh, T. G. Lee, and H. Y. Ha, 'Investigations of performance degradation and mitigation strategies in direct methanol fuel cells', Int. J. Hydrogen Energy, 34, 2043 (2009) https://doi.org/10.1016/j.ijhydene.2008.10.092
  5. J. Munk, P. A. Christensen, A. Hamnett, and E. Skou, 'The electrochemical oxidation of methanol on platinum and platinum + ruthenium particulate electrodes studied by in-situ FTIR spectroscopy and electrochemical mass spectrometry' J. Electroanal. Chem., 401, 215 (1996) https://doi.org/10.1016/0022-0728(95)04314-4
  6. J. -T. Li, Q. -S. Chen, and S. -G. Sun, 'In situ microscope FTIR studies of methanol adsorption and oxidation on an individually addressable array of nanostructured Pt microelectrodes' Electrochim. Acta, 52, 5725 (2007) https://doi.org/10.1016/j.electacta.2006.12.082
  7. F. Liu, M. Yan, W. Zhou, and Z. Jiang, 'In situ transmission difference FTIR spectroscopic investigation on anodic oxidation of methanol in aqueous solution' Electrochem. Comm., 5, 276 (2003) https://doi.org/10.1016/S1388-2481(03)00044-4
  8. P. K. Babu, Y. Y. Tong, H. S. Kim, and A.Wieckowski, 'Nanostructured electrode surfaces studied by electrochemical NMR' J. Electroanl. Chem., 524, 157 (2002) https://doi.org/10.1016/S0022-0728(02)00674-5
  9. Y. Paik, S. -S. Kim, and O. H. Han, 'Methanol Behavior in Direct Methanol Fuel Cells' Angew. Chem. Int. Ed., 47, 94 (2008) https://doi.org/10.1002/anie.200703190
  10. R. E. Gerald II, R. J. Klinger, and J. W. Rathke, 'Flat metal conductor principal detector element for NMR analysis of a sample' US patent, 6469507 B1
  11. R. E. Gerald II, J. Sanchez, C. S. Johnson, R. J. Klinger, and J. W. Rathke, 'In situ nuclear magnetic resonance investigations of lithium ions in carbon electrode materials using a novel detector' J. Phys.: Condens. Matter, 13, 8269 (2001) https://doi.org/10.1088/0953-8984/13/36/304
  12. O. H. Han and K. S. Han, 'Toroidal Probe Unit for Nuclear Magnetic Resonance', US patent, 7339378 B2
  13. D. K. Cheng, "Field and Wave Electromagnetics", 2nd ed., Addison-Wesley, New York (1989)
  14. H. D. W. Hill, "Probe for High Resolution" in: Encyclopedia of NMR, D. M. Grant and R. K. Harris, eds., Wiley, New York (1996)
  15. F.D. Doty, "Solid State Probe Design", in: Encyclopedia of NMR, D. M. Grant and R. K. Harris, eds., Wiley, New York (1996)
  16. H. Tawfik, Y. Hung, and D. Mahajan, 'Metal bipolar plates for PEM fuel cell-review' J. Power Sources, 163, 755 (2007) https://doi.org/10.1016/j.jpowsour.2006.09.088
  17. S. Y. Hwang, H. -I. Joh, M. A. Scibioh, S. -Y. Lee, S. -K. Kim, T. G. Lee, and H. Y. Ha, 'Impact of cathode channel depth on performance of direct methanol fuel cell' J. Power Sources, 183, 226 (2008) https://doi.org/10.1016/j.jpowsour.2008.04.043
  18. B. Xiao, H. Bahrami, and A. Faghri, 'Analysis of heat and mass transport in a miniature passive and semi passive liquid feed direct methanol fuel cell (DMFC)' J. Power Sources, in press https://doi.org/10.1016/j.jpowsour.2009.10.047
  19. K. -Y. Song, H. -K. Lee, and H. -T. Kim, 'MEA design for low water crossover in air-breathing DMFC' Electrochim. Acta, 53, 637 (2007) https://doi.org/10.1016/j.electacta.2007.07.044
  20. T. S. Zhao, R. Chen, W. W. Yang, and C. Xu, 'Small direct methanol fuel cells with passive supply of reactants' J. Power Sources, 191, 185 (2009) https://doi.org/10.1016/j.jpowsour.2009.02.033

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