Functionally Gradient Materials Preparation Of PEN For SOFC By Plasma Spray Digital Forming

The Solid Oxide Fuel Cell (SOFC) is a new type all solid-state energy conversion device operated at high temperatures with the advantages of high efficiency, fuel adaptability, fuel reformed within cell, no need using the precious metal electrode, good modularity and site fixed flexibility, etc. Therefore, the SOFC has become a very hot research subject in the domain of Fuel Cell.It is well known that the Positive-Electrolyte-Negative (PEN) is the key part of the SOFC, and it demands that Positive and Negative are high porous, Electrolyte is compact, the contact between electrode is fine. Besides; Problems about high fabrication cost and bad compatibility of power and volume, stop the commercialization operation of SOFC. Consequently, base on the Rapid Prototype technology, the research work of this paper which digital fabricate the three-dimensional complex shape functionally graded materials PEN part of SOFC by plasma spray will have a great contribution and value on the application and prevalence of SOFC.Base on the foregoing problems, the following aspects research work has been done in this paper:1) Presenting the technology that continuously fast fabricates the key part PEN of two-dimension corrugation and planar type SOFC, which are constructed from YSZ electrolyte with Ni-YSZ anode and LSCF cathode, by combining rapid prototype manufacture, plasma spray and robot digital forming technology.2) Adjusting and optimizing the process parameters, which influence the formability and porosity of coating; Simultaneously, improving the porosity of anode and cathode by adding hole-forming materials, and keeping electrolyte compact with process of laser sinter.3) The concept and principle Functionally Gradient Materials is used in the fabrication of PEN; Gradient coating is designed between anode, electrolyte and cathode, which improves the contact state of electrodes; With the help of new designed functionally gradient powder feeder and systemic examination, the consecutive gradient between Positive, Electrolyte and Negative 4) The micro structure of the key part PEN of two-dimension corrugation and planar type SOFC are analyzed and discussed by using analytical micro electron probe instrument and Energy Spectrum Analysis. Result indicates that coating thickness distributes equably, electrolyte is compact , anode and cathode are porous, these satisfy the structure desire. Besides, the component and organization of gradient coating is continuous changing. The method of functionally gradient materials preparation of PEN for SOFC by plasma spray digital forming is feasible and has advantage very much.4) Using the method of complex impedance spectra analyzed the electrical performance of planar PEN, the result indicate that with the temperature increment, the whole electric resistance, electric resistance of crystal grain and grain boundary decrease, and electric conductivity increase.. Furthermore, compared with the tape casting process, under the same temperature conditions, the plasma spray process has more advantages for reducing the electric resistance of PEN.