1

Figure 6

Interface conductivity (1/SRc) of the Ni/YSZ and Ni/CcYSZ electrodes as a function of log(Po ).

5. Conclusion

Planar type single cells with electrodes modified by mixed ionic-electronic conductors of CeYSZ and SDC were successfully fabricated and tested. An SDC thin layer was made at the cathode/electrolyte interface to reduce the ohmic resistance of ionic current at the interface. Ce02 was added in the Ni-YSZ cermet anode in order to increase the electronic conductivity of YSZ in the cermet. By these modifications we succeeded in reducing the interfacial overpotential and attained a high power density of 0.93W/cm2 using hydrogen as a fuel and air as an oxidizer. The SDC inter-layer was also found to be effective in improving the stability of cathode in long term operation.

References

1) Y. Matsuzaki et al„ Fuel Cell Seminar Abstract, Tucson, Nov. p-237 (1992)

2) JCEguchi et al., Solid State Ionics, 52, p-165(1992)

3) O. Yamamoto et al., Proc. of The 1 st Int. Symp. on Solid Oxide Fuel Cells., p- 242(1989)

4) C. Brugnoni et al., Solid State Ionics, 76, p-177(1995)

5) M. J. Vcrker et al., J. Electrochem. Soc., 130, p-78, (1983)

6) J. Mizusaki et al., J. Electrochem. Soc., 141, p-1676, (1994)

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