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Systematic analysis of the direct methanol fuel cell

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Abstract

The dynamic operating behaviour of the direct methanol fuel cell (DMFC) is governed by several physico-chemical phenomena which occur simultaneously: double layer charging, electrode kinetics, mass transport inside the porous structures, reactant distributions in the anode and cathode flowbeds etc. Therefore it is essential to analyse the interactions of these phenomena in order to fully understand the DMFC. These phenomena were initially analysed independently by systematic experiments and model formulations. Electrode kinetics were determined by fitting models of varying complexity to electrochemical impedance spectroscopy (EIS) measurements. Reaction intermediates adsorbed on the catalyst seem to play a key role here. To describe mass transport across the DMFC a one-dimensional model was formulated applying the generalised Maxwell–Stefan equations for multi-component mass transport and a Flory–Huggins model for the activities of mobile species inside the membrane (PEM). Also swelling of the PEM as well as heat production and transport were considered. Finally, the anode flowbed was analysed by observing flow patterns in different flowbed designs and measuring residence time distributions (RTDs). Detailed CFD models as well as simpler CSTR network representations were used to compare to the experimental results. Even the simpler models showed good agreement with the experiments. After these investigations the results were combined: the electrode kinetics model was implemented in the mass transport model as well as in the CSTR network flowbed model. In both cases, good agreement, even to dynamic experiments, was obtained.

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Abbreviations

c (mol m−3):

Molar concentration

d (m):

Thickness

i (mA cm−2):

Current density

n (mol m−2 s−1):

Overall molar flux density

r (mol m−3 s−1):

Reaction rate

t (s):

Time

T (K):

Temperature

U (V):

Voltage

z (m):

Cell coordinate perpendicular to cell plane

Z (\({\Upomega}\)):

Impedance

α (–):

Charge transfer coefficient

η (V):

Overpotential

\(\Uptheta\) (–):

Surface fraction

ϕ (V):

Electrical potential

AC:

Anode catalyst layer

AF:

Anode feed

CC:

Cathode catalyst layer

M:

Membrane (PEM)

a:

Anode

c:

Cathode

Cell:

Cell

CH3OH:

Methanol

CO:

Carbon monoxide

Dead:

Due to experimental delays (“dead time”)

H2O:

Water

O:

Oxygen

CFD:

Computational fluid dynamics

CSTR:

Continuously stirred tank reactor (i.e. lumped parameter model)

DMFC:

Direct methanol fuel cell

EIS:

Electrochemical impedance spectroscopy

PEM:

Polymer electrolyte membrane

PEMFC:

Polymer electrolyte membrane fuel cell

RTD:

Residence time distribution

VCS:

Electrode kinetics model according to [4]

References

  1. T. Schultz, Experimental and Model-based Analysis of the Steady-state and Dynamic Operating Behaviour of the Direct Methanol Fuel Cell (DMFC), Dissertation (Otto-von-Guericke University, Magdeburg, 2004). Free download: http://www.diglib.uni-magdeburg.de/Dissertationen/2004/thoschultz.htm

  2. Schultz T., Zhou S., Sundmacher K. (2001). Binny. Chem. Eng. Technol. 24:1223

    Article  CAS  Google Scholar 

  3. Carrette L., Friedrich K.A., Stimming U. (2001). Fuel Cells 1:5

    Article  CAS  Google Scholar 

  4. Vidaković T., Christov M., Sundmacher K. (2005). J. Electroanal. Chem. 580:105

    Article  CAS  Google Scholar 

  5. U. Krewer, System-oriented analysis of the dynamic behaviour of direct methanol fuel cells, Dissertation (Otto-von-Guericke University, Magdeburg, 2005). Free download: http://www.diglib.uni-magdeburg.de/Dissertationen/2005/ulrkrewer.htm

  6. Kauranen P.S., Skou E., Munk J. (1996). J. Electroanal. Chem. 404:1

    Article  CAS  Google Scholar 

  7. T. Vidaković, Kinetics of methanol electrooxidation on PtRu catalysts in a membrane electrode assembly, Dissertation (Otto-von-Guericke University, Magdeburg, 2005). Free download: http://www.diglib.uni-magdeburg.de/Dissertationen/2004/tanvidaković.htm

  8. Sundmacher K. (1999). J. Appl. Electrochem. 29:919

    Article  CAS  Google Scholar 

  9. Vidaković T., Christov M., Sundmacher K. (2004). Electrochim. Acta 49:2179

    Article  CAS  Google Scholar 

  10. U. Krewer, M. Christov, T. Vidaković, and K. Sundmacher, J. Electroanal. Chem. 589 (2006) 148.

    Article  CAS  Google Scholar 

  11. T. Schultz and K. Sundmacher, J. Power Sources accepted, 2006.

  12. T. Schultz, K. Sundmacher, J. Power Sources 145 (2005) 435.

    Article  CAS  Google Scholar 

  13. Schultz T., Sundmacher K. (2006). J. Memb. Sci. 276:272

    Article  CAS  Google Scholar 

  14. Krewer U., Song Y., John V., Luebke R., Matthies G., Sundmacher K., Tobiska L. (2004). Chem. Eng. Sci. 59:119

    Article  CAS  Google Scholar 

  15. U. Krewer, A. Kamat and K. Sundmacher, J. Electrochem. Soc. submitted.

  16. M. Mangold, M. Grötsch and A. Kienle, J. Process Control, submited.

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Correspondence to K. Sundmacher.

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Schultz, T., Krewer, U., Vidaković, T. et al. Systematic analysis of the direct methanol fuel cell. J Appl Electrochem 37, 111–119 (2007). https://doi.org/10.1007/s10800-006-9209-9

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  • DOI: https://doi.org/10.1007/s10800-006-9209-9

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