Showing papers by "Zongping Shao published in 2009"
TL;DR: In this article, a review of the current research activities on BSCF-based cathodes for intermediate-temperature (IT)-SOFCs is presented and analyzed to provide some guidelines in the search for the new generation of cathode materials for IT-SOFC.
398 citations
TL;DR: A site cation-ordered PrBaCo2O5+δ (PrBC) double perovskite oxide was synthesized and evaluated as the cathode of an intermediate-temperature solid-oxide fuel cell (IT-SOFC) on a samarium-doped ceria (SDC) electrolyte as mentioned in this paper.
320 citations
TL;DR: In this article, the relationship between the Zr doping content and structure, chemical stability, carbon dioxide resistivity, sinterability and electrochemical properties of BaZryCe0.2O3−δ (BZCYy), 0.8−yY0.0 and 0.4, are studied systemically using XRD, CO2-TPD, SEM, EIS and I-V polarization characterizations.
236 citations
TL;DR: In this article, a perovskite-type La 0.8 Sr 0.2 Cr 0.5 O 3 (LSCM) oxide was synthesized and evaluated as the electrode material of a symmetric solid-oxide fuel cell.
160 citations
TL;DR: In this paper, a simple glycine-nitrate auto-combustion by applying aqueous medium and constricting the reactions in the pores of cellulose fibers was used to synthesize spinel LiTiO.
127 citations
TL;DR: In this paper, an intermediate-temperature solid oxide fuel cell (IT-SOFC) was investigated using carbon as the fuel for an anode-supported SOFC with scandium-stabilized zirconia electrolyte and a La 0.8 Sr 0.2 MnO 3 cathode by applying a catalystloaded, activated carbon as fuel.
124 citations
TL;DR: LiFePO 4 /C composite was synthesized by mechanical activation using sucrose as carbon source as mentioned in this paper, and the product showed a capacity of 174µm/g at 0.1C rate and around 117µg at 20C rate with the capacity fade less than 10% after 50 cycles.
121 citations
TL;DR: Li4Ti5O12 was successfully fabricated by cellulose-assisted glycine-nitrate (cellulose-GN) combustion process at reduced temperature using anatase TiO2 solid as raw material of titanium.
74 citations
TL;DR: In this article, various M cations like Bi5+, Zr4+, Ce4+, Sc3+, La3+, Y3+, Al3+ and Zn2+ were incorporated into SrCoO3-delta (SC) lattices one by one via doping strategy to form a series of new SrCo0.95M0.05O3delta mixed oxides for membrane separation.
63 citations
TL;DR: In this paper, a novel γ-Al 2 O 3 supported nickel (Ni/Al 2O 3 ) catalyst was developed as a functional layer for Ni-ScSZ cermet anode operating on methane fuel.
52 citations
TL;DR: In order to improve the electrical conductivity of the SrSc 0.2 Co 0.8 O 3− δ (SrScCo) electrode, a composite of 70 ¼wt% SrScCo 0.6 O 3 − δ and 30 ¼ weight% Sm 0.5 CoO 3−δ (SmSrCo) was prepared and investigated for electrochemical oxygen reduction at intermediate temperatures as discussed by the authors.
TL;DR: In this article, a modified Pechini sol-gel technique was used to synthesize a mixed conducting ceramic membrane material (BSCF) for air separation in a relatively lower temperature.
TL;DR: LiFeP0 4 /C composite cathode for secondary lithium-ion battery was synthesized via a mechanochemical activation/sintering process adopting citric acid (CA) as carbon source as mentioned in this paper.
Abstract: LiFeP0 4 /C composite cathode for secondary lithium-ion battery was synthesized via a mechanochemical activation/sintering process adopting citric acid (CA) as carbon source. The carbon formation process, optimal carbon content, and electrochemical performance of the as-synthesized powders are investigated by thermogravimetry-differential scanning calorimetric analyzer, X-ray powder diffraction, CO 2 -temperature-programmed desorption (TPD), temperature-programmed reaction, scanning electron microscopy, impedance spectroscopy, and charge-discharge characterizations. The thermal decomposition of CA was found to conduct in two successive steps: It is first cracked to CH x between 50 and 400°C and then further decomposed to carbon at >500°C; both temperatures are lower than that of the sucrose. CO 2 -TPD characterization demonstrated that 5.0, 6.0, 6.75, and 8.0 wt % of CA applied during the synthesis resulted in carbon contents of 1.81, 3.23, 3.63, and 4.04 wt % in the final product, respectively. The cathode with its precursor containing 6.0 wt % CA shows highest discharge capacities of ~ 153 and 92 mA h g -1 at 1C and 20C rates, respectively, which are comparable to the best results reported for a LiFeP0 4 /C cathode. It then highly appreciates the mechanochemical activation/sintering process with CA as the carbon source in the synthesis of high performance LiFePO 4 /C.
TL;DR: In this article, the application of the SrSc0.8O3-delta perovskite as a cathode material on the Sm0.2Ce0.9 electrolyte for reduced-temperature operation solid oxide fuel cells (SOFCs) was investigated in detail.
Abstract: The application of the SrSc0.2Co0.8O3-delta (SScC) perovskite as a cathode material on the Sm0.2Ce0.8O1.9 electrolyte for reduced-temperature-operation solid oxide fuel cells (SOFCs) was investigated in detail. Oxygen reduction reaction (ORR) on the SScC cathode was studied by two-electrode impedance, three-electrode-polarization test, and four-probe dc conductivity measurement at various temperatures, oxygen partial pressures, and polarization values. The oxygen nonstoichiometry of SScC is 0.552 at 500 degrees C. An extremely high oxygen vacancy concentration in the SScC lattice decreased the resistances from oxygen adsorption, dissociation, and diffusion processes at low temperatures. This subsequently improved the electrochemical performance of the cathode. The polarization overpotential is only -110 mV for the SScC cathode at the current density of -1070 mA cm(-2) at 600 degrees C in air. The kinetics of ORR on the SScC cathode was studied by ac impedance, which revealed that the charge-transfer process was the rate-determining step due to the extremely low electrical conductivity of SScC.
TL;DR: In this paper, the morphology, microstructure and oxygen reduction reaction activity of the resulting Ag/BSCF electrodes were comparatively studied using Fourier transform infrared spectra, environmental scanning electron microscopy.
TL;DR: In this article, a Ni-anode-supported solid oxide fuel cell (SOFC) comprising a proton-conducting BaZr 0.4 Ce 0.5 Co 0.8 Fe 0.2 O 3 (BSCF) perovskite cathode was fabricated by the dual dry pressing/sintering process.
TL;DR: In this article, a thermally self-sustaining miniature power generation device was developed utilizing a single-chamber solid oxide fuel cell (SOFC) placed in a controlled thermal environment provided by a spiral counterflow "Swiss roll" heat exchanger and combustor.
Abstract: A thermally self-sustaining miniature power generation device was developed utilizing a single-chamber solid oxide fuel cell (SOFC) placed in a controlled thermal environment provided by a spiral counterflow "Swiss roll" heat exchanger and combustor. With the single-chamber design, fuel/oxygen crossover due to cracking of seals via thermal cycling is irrelevant and coking on the anode is practically eliminated. Appropriate SOFC operating temperatures were maintained even at low Reynolds numbers (Re) via combustion of the fuel cell effluent at the center of the Swiss roll. Both propane and higher hydrocarbon fuels were examined. Extinction limits and thermal behavior of the integrated system were determined in equivalence ratio―Re parameter space and an optimal regime for SOFC operation were identified. SOFC power densities up to 420 mW/cm 2 were observed at low Re. These results suggest that single-chamber SOFCs integrated with heat-recirculating combustors may be a viable approach for small-scale power generation devices.
TL;DR: In this article, solid precursors of LSM and LSSM were calcined at 1000 and 1150°C, respectively, to obtain products with similar specific surface area.
TL;DR: In this paper, the phase structure of the powder and microstructure of the membrane were characterized by XRD and SEM, respectively, and the optimum condition for membrane sintering was developed based on SEM and four-probe DC electrical conductivity characterizations.
Abstract: In this study, La0.4Sr0.6CoO3-delta (LSC) oxide was synthesized via an EDTA-citrate complexing process and its application as a mixed-conducting ceramic membrane for oxygen separation was systematically investigated. The phase structure of the powder and microstructure of the membrane were characterized by XRD and SEM, respectively. The optimum condition for membrane sintering was developed based on SEM and four-probe DC electrical conductivity characterizations. The oxygen permeation fluxes at various temperatures and oxygen partial pressure gradients were measured by gas chromatography method. Fundamental equations of oxygen permeation and transport resistance through mixed conducting membrane were developed. The oxygen bulk diffusion coefficient (D-v) and surface exchange coefficient (K-ex) for LSC membrane were derived by model regression. The importance of surface exchange kinetics at each side of the membrane on oxygen permeation flux under different oxygen partial pressure gradients and temperatures were quantitatively distinguished from the oxygen bulk diffusion. The maximum oxygen flux achieved based on 1.6-mm-thick La0.4Sr0.6CoO3-delta, membrane was similar to 4.0 x 10(-7) Mol cm(-2) s(-1) at 950 degrees C. However, calculation results show theoretical oxygen fluxes as high as 2.98 x 10(-5) Mol cm(-2) s(-1) through a 5-mu m-thick LSC membrane with ideal surface modification when, operating at 950 degrees C for air separation.
TL;DR: In this paper, mixed conducting oxides with the composition of Sr 1− x Y x Co 1− y Y y O 3− δ (x ǫ = 0.0-0.8, y ǔ = 0.0−0.1) were exploited and synthesized, and the resulted materials were investigated by X-ray diffraction, fourprobe dc conductivity, temperature-programmed desorption characterization, and oxygen permeability measurement.
TL;DR: In this article, the EDTA (ethylenediaminetetraacetic acid)-Citrate sol-gel process and a low-temperature auto-combustion process were used to synthesize LSCF powders.
TL;DR: In this article, hollow fiber membranes of mixed conducting perovskite La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 (LSCF) were prepared via the combined phase inversion and sintering technique and tested for air separation with a home-made reactor under the oxygen partial pressure gradient generated by the air/He streams.
TL;DR: In this paper, a perovskite powder was synthesized by a combined EDTA-citrate complexing process via low-temperature auto-combustion synthesis with NH4NO3 as an oxidizer and a combustion trigger.
TL;DR: In this article, the authors investigated the Cr doping effect of La0.75Sr0.25MnO3 on its phase stability and electrochemical performance as a solidoxide fuel cell (SOFC) anode.
TL;DR: In this article, the potential application of combustion synthesis of La(0.6)Sr (0.4)Co( 0.2)Fe(0 8)O(3-delta) (LSCF) based on a modified ethylenediaminetetraacetic acid (EDTA)-citrate complexing method with NH(4)NO(3) as combustion aid for ceramic oxygen separation membrane was systematically investigated.
TL;DR: In this article, Ru-CeO2 was used as a catalyst layer over a Ni-ScSZ cermet anode to catalyze the formation of syngas, which successfully reduced the nickel oxide to metallic nickel in the anode.
TL;DR: In this paper, the phase reactions between SrCoO x and Sm 0.2 Ce 0.8 O 1.9 happened at 900°C or higher, resulting in the incorporation of Sm and Ce into its lattice structure and led to substantial increase in the electrical conductivity and oxygen mobility of the electrode.
TL;DR: In this paper, a combined EDTA-citrate complexing method was used to synthesize perovskite-type mixed conducting oxides of SrCo1-yScyO3-δ (y=0.02-0.7).
Abstract: Perovskite-type mixed conducting oxides of SrCo1-yScyO3-δ (y=0.02-0.7) were synthesized by a combined EDTA-citrate complexing method. Different scandium doping concentrations in SrCo1-yScyO3-δ have significant effects on the phase structure, electrical conductivity, surface properties and oxygen permeation behaviour of the resultant membranes. SrCoO3-δ without scandium incorporation displayed a 2H BaNiO3-type structure with almost zero oxygen flux at high temperatures. Small amounts of Sc2O3 doping (y 0.1) were found to lower the membrane oxygen fluxes, with y³≥0.4 doped SrCo1-yScyO3-δ ceramics no longer showing any oxygen permeation.
TL;DR: In this paper, a conic Ba0·5Sr 0·5CoO3 (BSC) with conic particle shape was obtained by in situ templating of BSC with iron diffusing into the BSC lattice during calcination at high temperature.
Abstract: Conic Ba0·5Sr0·5Co0·8Fe0·2O3−δ (BSCF) functional composite oxide was synthesized via a simple in situ templating process. The treatment of the solid precursor with concentrated nitric acid resulted in the mismatch of ionic radius at A-site and B-site of the ABO3 perovskite, due to the oxidation of cobalt/iron ions, and the formation of Ba0·5Sr0·5(NO3)2 solid solution. Therefore, instead of the direct formation of BSCF oxide, an intermediate phase of Ba0·5Sr0·5CoO3 (BSC) in hexagonal lattice structure and with conic particle shape was preferentially formed during calcination at low temperature. BSCF perovskite was then produced by the in situ templating of BSC with iron diffusing into the BSC lattice during calcination at high temperature. Well-crystallized BSCF particles in conic shape were obtained by the calcination of the nitric acid treated precursor at 900°C.
TL;DR: In this paper, a novel SrNb0.1Co0.9O3−δelectrode material, which possesses not only high electrical conductivity but also large oxygen vacancy concentration at 400-600 °C, shows an excellent performance in the application of reduced temperature solid-oxide fuel cells.
Abstract: A novel SrNb0.1Co0.9O3−δelectrode material, which possesses not only high electrical conductivity but also large oxygen vacancy concentration at 400–600 °C, shows an excellent performance in the application of reduced temperature solid-oxide fuel cells.