Fuel cell characteristics

TABLE III Fuel Cells Characteristics Typical Operating Advantages... 

Figure 1.13 Fuel cell characteristics of a 5 cm DEFC recorded at llO C. Influence of the nature of the bimetallic catalysts (80 20 atomic ratio with 30% metal loading). Anode catalyst,...

Figure 1.14 Fuel cell characteristics of a 25 cm DEFC recorded with a 30% Pt-Sn (90 10) catalyst. Influence of the working temperature. Anode catalyst, 1.5 mgcrn [30% Pt-Sn (90 10)/XC72] cathode catalyst, 2 mgcm (40% Pt/XC72 from E-TEK) membrane, Nafion 117 ethanol concentration, 1 M. ( ) 50°C ( ) 70°C (A) 90°C (T) 100°C ( ) 110°C.

Figure 1.16 Fuel cell characteristics of a DEFC recorded at 90°C with a 60% Pt-Sn (90 10)/XC72 catalyst for different Nafion membranes. (A) Nafion 117 ( ) Nafion 115 ( ) Nafion 112.

As shown in this review, test equipment integrated with several diagnostic techniques is preferred for a deeper insight into the mechanisms that cause performance losses and spatial non-uniform distribution. As a consequence, more information, which is simultaneously obtained with these diagnostic tools, will strongly support development of empirical models or validate theoretical models predicting performance as a function of operating conditions and fuel cell characteristic properties. 

Some of the selected PEM fuel cell characteristics are presented in Table 3. 

Figure 16.2 Fuel cell characteristics for imidazole/HTFSI neutral salt at 130°C. Scan rate is 1 mV s. W.E. is a Pt-wire in Oz atmosphere, C.E. isaPt-wirein Hz atmosphere and R.E. is a Pt-wire in Hz atmosphere. (Reprinted by permission of the Publisher, The Royal Society of Chemistry)...

Figure 40. Fuel cell characteristics of a DEFC with a 25 cm surface area electrode recorded at 80°C with different catalysts (2M C2H5OH, N117).

The voltage of a working cell will be the lower, the higher the current I (i.e., the higher the current density i = IfS at the electrode s working surface area S). The current-voltage and the current-power relations are basic fuel-cell characteristics and have the same shape as those of conventional batteries (see Fig. 3.2). 

Tomczyk P (2006) MCFC versus other fuel cells—Characteristics, technologies and prospects. 

PEM fuel cell characteristics are generally described with polarization curves. The thermodynamic equilibrium potential of the hydrogen/oxygen reaction is reduced by various overvoltage terms that depend on mass transport, kinetic, and ohmic phenomena within cell. In other words, the output voltage of a single cell is attributable to different current, temperature, and pressure dependant factors [1]. 

Tomczyk P., MCFC versus other fuel cells characteristics, technologies and prospects, 7. Power Sources, 60, 858 (2006). 

Figure 10.13 Comparison of the fuel cell characteristics of a direct ethanol fuel cell with different anode catalysts operated at 90 °C. ( ) Pt/C,2.0mgPtcm- (T) Pt, Pd,/C 1.3 mg Pt cm ( ) Pt,W,/C, 2.0mg Ptcm ( ) PtiRui/ C, 1.3mg Ptcm M PtiSni/C, 1.3mgPtcm...

Membrane Type Conductivity" (S/cm) Fuel Cell Characteristics Comments Reference... 

FIGURE 6-25. Temperature distribution through a fuel cell characteristic cross-section (Adapted from [28]). 

Both activation and concentration losses are described as functions of current density and some additional factors (e.g. io,b). The values of these factors are determined for specific fuel cell characteristics and are obtained from experiment results. 

In order to determine the performance potential of fuel cells powered by bio-fuels, the resultsobtained were compared with two reference fuels hydrogen and natural gas. Fuel cell characteristics for two reference fuels hydrogen and methane were calculated for a comparative baseline. The type of fuel supplied is not the only... 

With the best will in the world, even an inspirational model is worth little without reliable validation. Hard experimental data are needed. Numerous papers came to hand in which experimental investigations were performed and results presented. Those results contained mainly fuel cell characteristics based on the current-voltage curve alone. A lack of narrative about experimental procedure and poor information on flow parameters during experiments would seriously undermine any attempt at a validation process for the models. It was crucial to obtain sound experimental data together with a complete rundown on the experimental procedures used. Almost out of the blue a golden opportunity presented itself in the form of cooperation with Politecnico di Torino. The deal was the Poles had to... 

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