The Structure, Electrical Properties And Stability Of Multilayered GDC/YSZ Eletrolyte Of Oxygen Ionic Conductor

As a third-generation fuel cell system of Solid Oxide Fuel Cells (SOFC) in an efficient, clean and wide adaptability and multi-fuel has a broad market prospects, and become one of the fastest growing new energy of technologies. The SOFC working temperature from 1000℃high temperature down to intermediate temperature(IT,500-800℃) range can reduce the high temperature reaction of group materials, reduce preparation costs and extend battery life, IT SOFCs become an important area of development. Oxygen ion conductor electrolyte material as the main components of SOFC, the operating temperature, stability and other parameters directly affect the SOFC performance, electrolyte film for SOFC can effectively reduce the operating temperature, has become a trend in the Temperature SOFC. Therefore, the study of oxygen ion conductor electrolyte nanometer multilayer film structure, electrical properties and stability has become an important research.In this paper, the GDC/YSZ multilayer oxygen ion conductor electrolyte film were synthesized on (0001) single crystal sapphire substrates by using reactive Magnetron Sputtering Technique. The phase,structure, surface morphology and electrical properties of oxygen ion conductor electrolyte of GDC/YSZ multilayers were characterized by X-ray Diffraction (XRD), Atomic Force Microscope (AFM), Transmission Electron Microscopy (TEM) and Electrochemical Impedance Spectroscopy. The results show that the multilayers when GDC was deposited firstly was irregular and the multilayers when deposited firstly YSZ showed (111) texture, conform to GDC and YSZ monolayer results. The growth of GDC/YSZ multilayers is a gradual process of roughening, as the interface numbers increases, the multilayer film roughness and grain size increases.Electrical test results showed that with the increase of the interface numbers, multi-layer film conductivity increased, but the conductance activation energy remained constant (～1.3eV).Studied in the temperature solid oxide fuel cell operating temperature (550-800℃) annealing of the YSZ/GDC multilayer structure, morphology and electrical properties, The results show that the annealed samples did not form YSZ-GDC solid solution phase, multi-layer film conductivity decreases slightly (reducing the percentage of<5%), reducing the causes of GDC layer may be due to the reduction of Ce4+ and the film grain growth.