Anode-supported cells testing

Figure 10.10 i-V characteristics (right-hand scale) of an anode-supported cell tested in hydrogen with different amounts of water vapour in the fuel. Dashed lines are the ASRs as deduced from Eq.(l), and the solid lines are the cell resistances after correction for conversion of the fuel, ASRcor (Fq-(3)). The cell temperature was SSO"Cand the fuel flow ivas 24 l/h in the case with 5% H2Oand20 l/h for the 21% HiOcase. The airflow... 

Figure 10.14 Impedance spectra of an anode-supported cell tested at 850° C with different fuel gases. Two measurements were performed In hydrogen/water vapour gas mixtures with either 24 or 6% water vapour and two measurements were performed in diluted hydrogen, with either nitrogen or helium as the diluent. The water vapour content in the diluted gas experiments was ca.6%. Rj. is invariant to changes in the fuel but both the water vapour content and the typeof diluent strongly affect thelowfrequettcy semicircle.

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

Self-supported SOFC can be classified into anode-supported and cathode-supported fuel cells. The SOFC assembly for laboratory testing has a shape of button with 1 - 2 cm in diameter and less than 500 im in thickness. The majority of these button cells are anode-supported cells due to the easy of their fabrication as compared with that of the cathode-supported cell. These self-supported fuel cell usually possess thin (5-20 p,m) electrolyte and can operate at reduced temperatures (< 800 °C). The low temperature operation is the key to decrease... 

Table 10,1 Contributions to ASR for a Rise-type anode-supported cell (Nl-YSZ/YSZ/tSM-YSZ) at 8S0°C tested in a plug flow-type configuration at S and 8S% fuel utilisation (FU). Rehji is calculated using a specific conductivity of YSZ of 0.045 S/cm, Sconnect is an estimation, Rp.eichem is the sum of typical anode and cathode polarisation resistances measured in separate electrode experiments, Rp.aiff is calculated using a diffusion coefficient of 10 cm /s, 30% porosity, a tortuosity factor of 3 and a thickness of 0.1cm, and fip,conver is Calculated using Eq. (10) with i = 0,5 A/cm ...

Although the TOFC state-of-the-art anode-supported cells possess a world record mechanical average strength of about 400 MPa [10], (as measured in round robin tests in previous EU projects), statistical analysis of the strength behaviour bears evidence that most cells may behave unreliably under real dynamic operation conditions. Expressed according to Weibull statistical analysis (failure probability as function of applied mechanical stress), the Weibull modulus is in the range of 8-10 (see Fig. 9). 

Supported nanoparticles are the main catalysts used in current fuel cell devices. The combined DFT, single crystal, polycrystalline, and electrochemical experiments demonstrated that WC and Pt/WC have catalytic properties that are promising for use as anode DMFC electrocatalysts. These fundamental results still left questions unanswered as to how these materials could be incorporated into a realistic device. These questions led to studies of WC and Pt/WC nanoparticles in a fuel cell test station [23]. The WC nanoparticles were obtained from Japan New Metals Company. The Pt/WC nanoparticles were prepared with a 10 wt% Pt loading using incipient... 

Figure 9.16 Current density (700 mV) at 600, 650, and 700 °C of tested anode-supported single cells with an LSC cathode as function of sintering temperature.

P.V., and Hagen, A. (2008) Study of internal and external leaks in tests of anode-supported SOFC. Fuel Cells, 8, 385-393. 

T.N. Lin, M.C. Lee, L.S. Lee, W.X. Kao, J.C. Chang, and R.J. Yang, Fabrication and Performance Test of an Yo2Zro.803.6 Electrolyte Film by The Spin-coating Method for an Intermediate-temperature Anode-supported Solid Oxide Fuel Cells, Submitted, (2012). 

Fig. 6.31 Performance of direct-biogas SOFC 1 month test of internal reforming SOFC running on simulated and desulfurized actual biogases at 800°C using anode-supported button cells...

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