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Noponen, Matti; Hottinen, Tero; Mennola, Tuomas; Mikkola, Mikko; Lund, Peter

doi:10.1023/a:1021250418645

Cited by 47 publications

(20 citation statements)

References 6 publications

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“…(8,4) and (7,2) had higher resistances than the other segments. It was shown earlier by Noponen et al [21] that small deviations in segment resistances do not radically change the mass transfer characteristics in the cell. Thus, it is feasible to use the segmented cell as a validation tool.…”

Section: Methodsmentioning

confidence: 76%

A Two‐Phase Non‐Isothermal PEFC Model: Theory and Validation

Noponen

Birgersson²,

Ihonen

et al. 2004

Fuel Cells

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A two‐dimensional, non‐isothermal, two‐phase model of a polymer electrolyte fuel cell (PEFC) is presented. The model is developed for conditions where variations in the streamwise direction are negligible. In addition, experiments were conducted with a segmented cell comprised of net flow fields. The, experimentally obtained, current distributions were used to validate the PEFC model developed. The PEFC model includes species transport and the phase change of water, coupled with conservation of momentum and mass, in the porous backing of the cathode, and conservation of charge and heat throughout the fuel cell. The current density in the active layer at the cathode is modelled with an agglomerate model, and the contact resistance for heat transfer over the material boundaries is taken into account. Good agreement was obtained between the modelled and experimental polarization curves. A temperature difference of 6 °C between the bipolar plate and active layer on the cathode, and a liquid saturation of 6% at the active layer in the cathode were observed at 1 A cm–2.

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Section: Methodsmentioning

confidence: 76%

A Two‐Phase Non‐Isothermal PEFC Model: Theory and Validation

Noponen

Birgersson²,

Ihonen

et al. 2004

Fuel Cells

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“…[22][23][24][25] This group's approach is similar to that of Stumper et al [18] in that an array of shunt resistors (48 0.1 W) is used to ascertain the current distribution, in this case of a free-breathing cathode PEFC (5 cm 5 cm flow-field). In this technique, some additional control is obtained by the ability to adjust the contact pressure of each of the contact electrodes in turn.…”

Section: Contact Resistancementioning

confidence: 99%

“…It was shown that localised cell resistance can also be derived from current interrupt measurements. [23] Other leaders in this area include Mench et al at Penn State who have, for example, examined the current distribution within a DMFC consisting of ten contact electrodes. [26,27] Each of the contacts was controlled using a commercially available battery/fuel cell test system, effectively a multi-channel potentiostat.…”

Section: Contact Resistancementioning

confidence: 99%

What Happens Inside a Fuel Cell? Developing an Experimental Functional Map of Fuel Cell Performance

et al. 2010

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Fuel cell performance is determined by the complex interplay of mass transport, energy transfer and electrochemical processes. The convolution of these processes leads to spatial heterogeneity in the way that fuel cells perform, particularly due to reactant consumption, water management and the design of fluid-flow plates. It is therefore unlikely that any bulk measurement made on a fuel cell will accurately represent performance at all parts of the cell. The ability to make spatially resolved measurements in a fuel cell provides one of the most useful ways in which to monitor and optimise performance. This Minireview explores a range of in situ techniques being used to study fuel cells and describes the use of novel experimental techniques that the authors have used to develop an 'experimental functional map' of fuel cell performance. These techniques include the mapping of current density, electrochemical impedance, electrolyte conductivity, contact resistance and CO poisoning distribution within working PEFCs, as well as mapping the flow of reactant in gas channels using laser Doppler anemometry (LDA). For the high-temperature solid oxide fuel cell (SOFC), temperature mapping, reference electrode placement and the use of Raman spectroscopy are described along with methods to map the microstructural features of electrodes. The combination of these techniques, applied across a range of fuel cell operating conditions, allows a unique picture of the internal workings of fuel cells to be obtained and have been used to validate both numerical and analytical models.

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“…After it was noticed that the MEA could not endure the gas diffusion layer segmentation, only unsegmented gas diffusion layers were used. This would therefore mean that the real current distribution at the electrode is somewhat more pronounced than the measured quantities because of the current smoothing, as discussed in [43].…”

Section: Effect Of Gas Diffusion Layer Segmentationmentioning

confidence: 99%

Current distribution measurements in a PEFC with net flow geometry

Noponen¹,

Ihonen

Lundblad

et al. 2004

Journal of Applied Electrochemistry

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A measurement system for current distribution mapping for a PEFC has been developed. The segmented anode is constructed so as to have high thermal conductivity in order to prevent the formation of large temperature gradients between the electrodes. The construction is therefore feasible for use at high current densities. Both segmented and unsegmented gas diffusion layers are used. The effect of inlet humidification and gas composition at the cathode side is studied. In addition, two different flow geometries are studied. The results show that the measurement system is able to distinguish between current distribution originating from differences in proton conductivity, species concentration and gas diffusion layer properties.

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Untitled

Cited by 47 publications

References 6 publications

A Two‐Phase Non‐Isothermal PEFC Model: Theory and Validation

A Two‐Phase Non‐Isothermal PEFC Model: Theory and Validation

What Happens Inside a Fuel Cell? Developing an Experimental Functional Map of Fuel Cell Performance

Current distribution measurements in a PEFC with net flow geometry

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