%0 Thesis
%A Han, Feng
%T Sol-gel and nano-suspension electrolyte layers for high performance solid oxide fuel cells
%V 100
%@ 1866-1793
%I Ruhr-Universität Bochum
%V Dr. (Univ.)
%C Jülich
%M PreJuSER-15103
%@ 978-3-89336-694-1
%B Schriften des Forschungszentrums Jülich : Energie & Umwelt / Energy & Environment
%D 2010
%Z Record converted from VDB: 12.11.2012
%Z Ruhr-Universität Bochum, Diss., 2010
%X Solid oxide fuel cell (SOFC) is regarded as one of the most efficient and environmental-friendly devices for direct conversion of chemical energy into electricity. For commercialization of SOFCs, the long-term stability and as well as reliability of the system have to be guaranteed, and the manufacturing cost has to be reduced. This can be realized by reducing the operation temperature down to 650 ºC, while maintaining adequate system power output. In this work, low-cost wet-chemical processing techniques have been applied to fabricate thin gas-tight electrolyte layers for high performance SOFC applications. The focus of this work is threefold: (1) to prepare sols with nano-scaled particle size distribution and excellent layer formation properties, (2) to deposit thin gas-tight electrolyte with thickness of about 1 μm and a rather low helium leak rate under 2.0x10$^{-5}$ (hPa·dm$^{3}$)/(s·cm$^{2}$), (3) to manufacture and characterize SOFCs with high electrochemical performance. The as-prepared single cells with thin gas-tight electrolyte layers showed excellent electrochemical performance. At a cell voltage of 0.7 V, the cells reached high current densities of more than 3 A/cm$^{2}$, 1.5 A/cm$^{2}$ and 1.0 A/cm$^{2}$ at 800 °C, 650 °C and 600 °C, respectively, which are the SOFCs with the highest power density ever since reported. According to the electrochemical impedance spectroscopy investigation, the area specific ohmic resistances of the single cells are more than 80% lower than the cells with conventional 10 $\mu$m thick electrolytes manufactured by Forschungszentrum Jülich. Due to the excellent performance, the life time and stability of the SOFCs is expected to be improved by operating the cells at reduced temperature (650 ºC to 700 ºC) and increased cell voltage. Additionally, the manufacturing cost of the SOFC system can be effectively reduced.
%F PUB:(DE-HGF)11 ; PUB:(DE-HGF)3
%9 Dissertation / PhD ThesisBook
%U https://juser.fz-juelich.de/record/15103