Search academic texts

Information × Registration Number 0219U100760, 0116U003503 , R & D reports Title Diffusion processes in ceramic fuel cells. popup.stage_title Head Vаsyliev Oleksаndr D., Доктор фізико-математичних наук Registration Date 11-03-2019 Organization Institute for Problems in Materials Science popup.description2 The object of the study is the diffusional features of microstructure evolution in zirconiaceramicelectrolytesduring sintering and theireffects on materials's properties. The goal of the study is a further enhancement of ceramic fuel cells and development of a theory of structural sensitivity of their properties. Methods of research: scanning electron microscopy, x-ray diffraction, impendance spectroscopy, modeling. Considering the processes of powderconsolidation, sintering of ceramics and the refinement of their structure as thermoactivated, relations,which generalize the dependence of mechanical behaviour of solid electrolytes on the quality of interfaces between subgrains and grains, the size of the latters, andthe porosity as well were established. The properties of grain boundaries and complexions were examined via mechanical behavior and impedance spectroscopy data. For the first time, it allowed to distinguish the boundaries of subgrains and grains not only fractographically, but quantitatively via their electrical properties revealed with impedance spectroscopy. The diagram of the equilibria in NiO - ZrO2 (YSZ) system was created. It has been established that NiO - ZrO2 does not form chemical compounds. Instead, the interaction in the NiO - ZrO2 system has an eutectic nature. The solubility of NiO in ZrO2 is ~1-mol. %. For a cathode electrode, the diffusion of Ce and Gd, as components of cathode protective layer against Cr, have been established.Annealing samples in Ar-30-vol.% H2reducing atmosphereis enhancingthe Ce and Gd diffuson into the electrolyte much higer than Zr from the electrolyte into the protective layer. Product Description popup.authors popup.nrat_date 2020-04-02 Close