Single-cell tests

Trembly JP, Marquez Al, Ohm TR, and Bayless DJ. Effects of coal syngas and H2S on the performance of solid oxide fuel cells single-cell tests. J Power Sources 2006 158 263-273. 

The atmospheric pressure on-site short stack consisting of 32 cells obtained an initial performance of 0.65 volts/cell at 200 ASF (215 mA/cm ) or 0.139 W/cm. The performance degradation rate was less than 4 mV/1000 hours during the 4500 hour test. Single cells tested at atmospheric conditions achieved a 500 hour performance of approximately 0.75 volts/cell at 225 ASF... 

The 1-Vcurves from single cell tests with the Pt-Ru 40 wt% catalysts supported on thick H-CNE and nanotunneled H-CNE (Pt 1.33, Ru 0.67 and CNE 3mgcm ) and with the Pt-Ru 60 wt% E-TEK catalyst (Pt 2, Ru 1 and C 2 mg cm ) (5 mg slurry hand-brushed on carbon paper) are shown in Eigure 3.6, and their maximum power densities are listed in Table 3.2. The maximum power densities produced by the E-TEK catalyst at 30 and 90 ° C were 41 and 140 mWcm , respectively. The maximum... 

This section examines some experimental evidence for the transient behavior of individual cells evaluated on single-cell test stands and stacks contained within full systems. Results from models developed to help understand some of the detailed physical effects that influence cell performance are also examined. The goal is to introduce, albeit in brief, some of the principle dynamic characteristics of single cell and full stack performances. Single cell studies are important since they isolate the cell in a well understood and controlled environment thereby removing the effects of other external processes (e g., reforming) which may have their own transient behavior that affects cell operation (e g., controlling cell input fuel composition). Such... 

Single-cell tests - anode-supported cells... 

Figure 15 Single-cell test stand overview...

Development of SOEC materials, including anode, cathode, and electrolyte and development of single cell testing system. 

The electrode-electrolyte assembly was investigated in a single cell test station. After installing the MEA in the fuel cell housing, water was supplied to the anode and cathode backing layers and the cell was warmed-up step-wise from room temperature to 145°C. The polarization curves obtained for the fuel cells equipped with the Nafion-silica and Nafion-silica-PWA membranes, under same conditions in presence of oxygen feed at cathode and 2M methanol solution at anode, are reported in Fig. 6. 

The hollow ATO-PANI spheres obtained via the Pickering approach were decorated by Pt nanoparticles using a standardized polyol process. The chosen synthesis protocol for Pt decoration used mild conditions, which hence did not impact the hollow sphere structure. The hollow spheres were then sprayed onto a commercial Nation membrane and applied at the cathode side of an MEA. Figure 7.14a depicts a cross-sectional SEM image of the oxidic hollow spheres. It can be clearly observed that the sphere structure is maintained after the polyol process for Pt decoration. Single cell tests of the novel electrode design showed a maximum power density of 58 mW cm and a platinum utilization... 

Picture of a single cell test fixture. Courtesy of Dalian Institufe of Chemical Physics, Chinese Academy of Sciences. 

Figure 2.5 shows the actual results from a single cell test with a cathode Ft loading of 0.40 mg cm". The OCV was 0.98 V. The resistance of the cell was found to be around 80 mQ cm, measured by the impedance technique at current densities of 0.1 and 0.4 A cm , as shown in Figure 2.6. It is clear from Figure 2.5 that even after the iR correction, the V-1 curve still shows significant voltage decline with increase in the current density, implying that in this iR-dominated region there are still voltage losses due to activation and mass transport.

Performance change during 6001 hours of single cell test using a 50 gm PFSA membrane. Courtesy of MTI Micro Fuel Cells. 

Figure 9.18 Two types of test housing for ASC single-cell testing at FZJ (a) first type of test housing (b) present test housing.

Unfortunately, up to now only limited information has been pubhshed about post-test analysis, methods, and results, and this is trae of our own research center in addition to any other developer, be it companies or R D centers [1-4]. Only single effects after stack operation, single-cell testing, or model experiments and theoretical considerations have been published, such as metal corrosion, Cr poisoning, and thermodynamics [5-15]. Therefore, this chapter summarizes for the first time the stack dissection method, the underlying reasons for stack post-test analysis, the individual characterization techniques and methods, and the results obtained so far. 

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