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Voltage losses in fuel cells

Iczkowski RP, Cutlip MB. Voltage losses in fuel-cell cathodes. / Electrochem Soc 1980 127(7) 1433-40. [Pg.65]

It is essential to minimize any voltage loss in fuel cells and water electrolysis for energy conversion. As a result, highly sophisticated membrane electrode assemblies (MEA) have been developed to optimize contact between the membrane and the electrocatalyst in the electrodes. Similarly, for the first organic SPE electrosyntheses [2], electrically conductive porous platinum or gold layers inside of the surfaces of Nation membranes were used, prepared by a chemical method similar to [7]. [Pg.845]

Electrochemical impedance spectroscopy (EIS) has also been discussed in Chapter 3. EIS is generally used to diagnose the performance limitations of fuel cells. There are three fundamental sources of voltage loss in fuel cells kinetic losses (charge-transfer activation), ohmic losses (ion and electron transport), and mass transfer losses (concentration). EIS can be used to distinguish and... [Pg.277]

However, bulk resistivity is not a significant source of voltage loss in fuel cells, even for relatively high-resistivity plates. For example, a 3-mm thick molded graphite/composite plate with bulk resistivity as high as 8 mQcm would result in about 2.4 mV voltage loss at lA/cm. Much higher resistance results from the interfacial contacts, such as between the bipolar plate and the gas diffusion layer. [Pg.105]

Ohmic losses, in fuel cell voltages, 12 207 Ohmic polarization, batteries, 3 425—426 Ohnesorge number, 23 183, 190 Oil absorption, by silica, 22 371 Oil additives... [Pg.643]

For MEA designers or fuel cell stack engineers, a polarization curve is an immensely useful practical analysis tool. It allows for a comparative assessment of sources of voltage losses in the cell, fuel cell failure modes, critical or limiting current densities, as well as impacts of degradation and water management. For materials scientists, the polarization curve entails useful information on performance effects... [Pg.577]

As a measure for this efficiency, clearly the cell voltage of the fuel cell compared to that of the electrolysis is a first tool. Nowadays we have values of 0.8-1.8 V, that is, the ratio is 0.45. In the future, 0.9-1.2 V may be achieved, that is, 0.75. But this value is somewhat optimistic, if the Faradaic losses (current efficiencies) and the energy losses resulting from electrolysis and fuel cell operation are taken into account, too, amounting surely to an additional loss of 10-15%. [Pg.305]

The overall voltage loss in the fuel-cell cathode is a complex combination of interfacial kinetics and mass and charge transport losses. Consequently, model interfacial systems are best suitable to resolve and directly study the ORR at the Pt/ionomer interface. Such model... [Pg.616]

At the level of membrane operation in the fuel cell, considering bulk-hke water as the active medium in well-hydrated membranes implies that hy-drauhc permeation should be regarded as the major mode of water back transport that counterbalances the electro-osmotic drag. This balance between electro-osmotic drag and water backflux determines the degree of membrane dehydration at the interface between membrane and anode as well as the critical fuel cell current density at which voltage losses in the membrane increase dramatically, i.e. in a highly non-ohmic fashion. [Pg.49]

In this section, we construct several analytical polarization curves of PEMFCs and high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). In these types of cell, owing to the excellent kinetics of the hydrogen oxidation reaction, the polarization voltage of the anode is negHgible. The voltage loss in a PEMFC is determined by the oxygen transport, ORR kinetics, and the cell resistivity. [Pg.658]


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See also in sourсe #XX -- [ Pg.61 , Pg.65 ]




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