Search

Abstract: Anode-supported solid oxide fuel cells (SOFCs) have attracted much attention in recent years because of their lower operating temperature. For the preparation of anode-supported SOFCs, one of the key steps is the production of dense electrolyte films on the porous anode substrate. In this study, Ce0.9Gd0.1O1.95 (GDC) electrolyte films with the thickness range of 1–75μm are successfully prepared on porous NiO-GDC substrates by simple, rapid and cost-effective methods: dry co-pressing method and spray dry co-pressing method. The open porosity of the NiO-GDC substrates is approximately 23%, and the porosity including closed pores of the GDC electrolyte films is less than 2.6%. The prepared GDC electrolyte films are homogenous, dense and well adhered to the porous NiO-GDC substrates, without cracks and connecting pores observed. The results of helium gas permeability tests show that the prepared GDC electrolyte films are gas-tight. Therefore, it is expected that the developed method for thin electrolyte films provides a simple and useful technique for producing electrolytes for anode-supported SOFCs. [Copyright &y& Elsevier]

Abstract: In the present paper, we investigated the electrical performance of anode-supported solid oxide fuel cells (SOFCs) composed of Gd0.1Ce0.9O1.95 (GDC) electrolyte films of 1–75μm in thickness prepared by simple and cost-effective methods (dry co-pressing process and spray dry co-pressing process), and discussed the effect of thickness of the GDC electrolyte films on the electrical performance of the anode-supported SOFCs. It was shown that reducing the thickness of the GDC electrolyte films could increase the maximum power densities of the anode-supported SOFCs. The increase of the maximum power densities was attributed to the decrease of the electrolyte resistance with reducing the electrolyte thickness. However, when the thickness of the GDC electrolyte films was less than a certain value (approximately 5μm in this study), the maximum power densities decreased with the decrease in the thickness of the GDC electrolyte films. The calculated electron fluxes through the GDC electrolyte films increased obviously with reducing the thickness of the GDC electrolyte films, which was the reason why the maximum power densities decreased. Therefore, for anode-supported SOFCs based on electrolytes with mixed electronic–ionic conductivity, there was an optimum electrolyte thickness for obtaining higher electrical performance. [Copyright &y& Elsevier]

Abstract: A simple, rapid and cost-effective technique, spray dry co-pressing process, was developed to prepare dense electrolyte thin films on porous anode substrates. Gadolinium doped ceria (GDC) electrolyte thin film with the thickness of 4μm was prepared successfully on porous NiO–GDC anode substrate by the spray dry co-pressing process. The GDC electrolyte thin film was dense and uniform, and was well bonded to the porous NiO–GDC anode substrate. An anode-supported solid oxide fuel cell (SOFC) with 4μm GDC electrolyte thin film was fabricated and its performance was evaluated at 400–600°C with humidified hydrogen (3 vol.% H2O) as the fuel. The single cell showed an open circuit voltage (OCV) of 0.91V and maximum power density of 771mWcm−2 at 600°C. The results demonstrate that the dense GDC thin films prepared by the spray dry co-pressing process are suitable for low-temperature anode-supported SOFC applications. [Copyright &y& Elsevier]

Spray coating method is a cost-effective technique suitable for the preparation of uniform and large-area thin films. This article presents findings on the preparation of dense electrolyte thin films by spray coating method. Dense, crack-free Gd-doped CeO2 (GDC) thin films with a thickness of approximately 2 µm were successfully prepared on porous NiO-GDC substrates. The influence of the dispersion of GDC nanopowders in susupension on the microstructure of the thin films was investigated. Results show that agglomeration of GDC nanopowders in suspension resulted in a porous microstructure and a densely packed microstructure was obtained for the film prepared from a well-dispersed suspension. [ABSTRACT FROM AUTHOR]

Abstract: Nanocrystalline fluorite type samarium doped ceria (SDC) electrolyte thin film for intermediate temperature-solid oxide fuel cells (IT-SOFCs) application were prepared on the dense and porous substrates at low temperatures of 573–1373K using a novel citrate sol–gel route combined with a sol suspension spray coating technique. Thermogravimetric analysis showed that the decomposition of the citrate gel film and the initial crystallization of the SDC occurred at a low temperature of about 590K. XRD examination revealed that the annealing of the green film at temperatures of 573–1373K provided cubic nanocrystalline SDC phase. The crystallite sizes were in the range of 9–19nm. Microscopic observations indicated that the derived film was homogeneous, dense and crack-free without pinholes. The desired thickness for preparation of thin electrolyte films from hundreds of nm to several μm should be controllable and feasible by repeating the simple and inexpensive citrate sol–gel spray coating process. [Copyright &y& Elsevier]