Papers by Keyword: BSCF

Abstract: The ionic conductivity, super conductivity, ferroelectricity, and magnetic resistance of barium strontium cobalt ferrite (BSCF) make it a good solid cathode material. This study aims to investigate the influence of milling process and calcination temperature on the behaviour of nanocomposite cathode BSCF–samarium-doped ceria (SDC). The BSCF–SDC composite powders were mixed using two milling processes, namely, wet milling and dry milling. The composite cathode powders were mixed through wet milling by high-energy ball milling at 550 rpm for 2 hours. For dry milling, the powders were milled at 150 rpm for 30 minutes. The powders then underwent calcination at 900 °C, 950 °C, 1050 °C, and 1150 °C for 2 hours. The composite cathodes were examined on the basis of phase and microstructure through field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD), respectively. In conclusion, the selection of suitable milling process and calcination temperature is important in eliminating secondary phases in BSCF–SDC composite cathodes and in enhancing their properties.

Abstract: This study presents the preparation of barium strontium cobalt ferrite (BSCF)–samarium doped ceria (SDC) added samarium doped ceria carbonate (SDCC) cathode for solid oxide fuel cell (SOFC). The aim of this study is to investigate the effect of heat treatment on compatibility and characterization of BSCF composite. Calcined BSCF was mixed with SDCC and SDC by ball milling at 150 and 200 rpm respectively. Subsequently, both were uniaxially pressed to form pellets and sintered at 600°C for 2 hours. The BSCF behavior of composite samples was characterized via X-ray diffraction to determine the crystalline phase of BSCF composite. Fourier transform infrared spectroscopy was used to determine the existence of carbonate bond. Field emission scanning electron microscopy was used to examine the grain morphology. The crystalline BSCF phase percentage increased and secondary phases reduced when the milling speed decreased. After milling, BSCF composites still displayed uniform elemental distribution. Heat treatment has an impaired crystalline phase of perovskite BSCF. Without heat treatment, the BSCF composites showed agglomerate and unmolded particles.

Abstract: The phase instability of Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF) is widely reported in atmospheres containing carbon dioxide, which affects the long term electrochemical performance. The aim of this study is to investigate the phase stability of BSCF under the influence of milling and calcination temperature. Commercial BSCF powder was milled at 200 and 500 rpm and subsequently calcined at 750, 800 and 900 °C. The BSCF samples were characterized by using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). Secondary phases that were triggered after milling, however reduced with the increase of calcination temperature up to 800 °C. It was also found that the reduction of crystallite size and particle size at increased calcination temperature might be affected by the removal of these secondary carbonate phases. Moreover, the removal of carbonate was clearly evidenced in FTIR spectra by the reduction of carbonate signal intensities. In brief, a minimum calcination temperature of 900 °C was suggested for successful carbonate removal and recovery of single BSCF phase.

Abstract: Oxygen-permeable perovskite ceramics with mixed ionic-electronic conducting properties can play an important role in the high temperature separation of oxygen from air. Such membranes are envisaged for application in catalytic membranes reactors and in oxy-fuel and pre-combustion technologies for fossil fuel power plants enabling CO2 capture. Since large-scale gas separation applications demand high membrane surface/volume ratios, membranes with capillary or hollow fiber geometry have a distinct advantage over tubular and flat sheet membranes. The fabrication and performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) capillary membranes is presented. The capillaries were made by a spinning technique based on phase inversion using a sulfur or non-sulfur containing polymer binder. Attention is given to the polymer solution and ceramic spinning suspension in order to avoid the formation of macrovoids and achieve gastight membranes. The comparison of the performance of sulfur-free and sulfur-containing BSCF capillaries with similar dimensions revealed a profound impact of the sulfur contamination on both the oxygen flux and the activation energy of the overall oxygen transport mechanism. In addition the effect of activation layers on oxygen permeation is studied.

Abstract: Tape casting is widely used in industrial scale for production of multilayer ceramic capacitors or substrates for different applications. In 2009, it was successfully introduced as standard shaping technology for 3 (BSCF) are shown. The entire scope from the preparation of the used powders, the different manufacturing steps and their optimization potential up to the final tape-cast product will be discussed. The influence of the use of pore forming agents, heat treatment or other parameters during processing will be described in detail. Finally, the option of sequential tape casting of different materials for graded structures as a future step in shaping technology will be presented for different applications.

Abstract: In recent years, one dimensional nanostructure, nanofibers with unique properties have been subjected of intense research due to potential properties in many applications. This study presents synthesize of Perovskite-type Ba0.5Sr0.5Co0.2Fe0.8O3−δ (BSCF) nanofibers using sol-gel via electrospinning as a cathode for intermediate temperature solid oxide fuel cell. BSCF nanofibers are prepared by treating electrospun polyvinyl Pyrrolidon/ Ba0.5Sr0.5Co0.8Fe0.2O3−δ composite fibers at high temperature in an air atmosphere. BSCF nanofibers were characterized by x-ray diffraction (XRD) to observe desired structure, scanning electron microscopy (SEM) to investigated the morphology of fibers, and Brunauer, Emmett and Teller (BET) for measuring the surface area. To the best of our knowledge, investigation on Ba0.5Sr0.5 Co0.2 Fe 0.8O3−δ nanofibers has not been reported up to now.

Abstract: A recently reported promising new perovskite oxide cathode material, Ba0.2Sr0.8Co0.8Fe0.2O3−δ, (BSCF) (with x = 0.2 and y = 0.8) of high purity for intermediate-temperature solid oxide fuel cells (IT-SOFCs) was synthesised in the current work by using the co-precipitation method. The result indicated a precursor with a well-defined composition of fine particle size, high homogeneity, and high reactivity. After calcining has been developed at 900°C, the individual oxides from ammonium oxalate were alloyed into nanostructured perovskite (with x = 0.2 and y = 0.8) Ba0.2Sr0.8Co0.8Fe0.2O3 of high purity. The thermal properties, phase constituents, surface area and microstructure of the samples were characterised by TGA, XRD, BET, SEM and EDX techniques respectively. The results show that the BSCF powders have cubic perovskite-type structure with fine particle size, high surface area and high homogeneity. The current method employed is found to be very reliable for the synthesis of BSCF.