Co-reporter:Weiting Zhan, Yucun Zhou, Ting Chen, Guoshuan Miao, Xiaofeng Ye, Junliang Li, Zhongliang Zhan, Shaorong Wang, Zhenyan Deng
International Journal of Hydrogen Energy 2015 Volume 40(Issue 46) pp:16532-16539
Publication Date(Web):14 December 2015
DOI:10.1016/j.ijhydene.2015.08.073
•LSC, LSCF and SBSC infiltrated SSZ cathodes were prepared by the infiltration method.•800–1400 h stability tests of the infiltrated cathodes were investigated at 620 °C.•The degradation was caused by the morphological change of the infiltrated particles.Here we report the electrochemical performance and long-term stability of La0.8Sr0.2CoO3−δ (LSC), La0.58Sr0.4Co0.2Fe0.8O3−δ (LSCF) and SmBa0.5Sr0.5Co2.0O5+δ (SBSC) infiltrated (ZrO2) 0.89(Sc2O3) 0.1(CeO2) 0.01 (SSZ) cathodes at low temperatures. At 700 °C, the initial polarization resistance of the infiltrated cathodes increased in following order: SBSC-SSZ (0.054 Ω cm2)
Co-reporter:Da Han, Hao Wu, Junliang Li, Shaorong Wang, Zhongliang Zhan
Journal of Power Sources 2014 Volume 246() pp:409-416
Publication Date(Web):15 January 2014
DOI:10.1016/j.jpowsour.2013.07.113
•SmBa0.5Sr0.5Co2O5+δ/LSGM cathode of nanostructure is fabricated by impregnation method.•The lowest ARS values of SmBa0.5Sr0.5Co2O5+δ/LSGM cathode is 0.035 Ω cm2 at 550 °C and 0.12 Ω cm2 at 500 °C.•Power densities of 1.5 W cm−2 at 600 °C and 0.70 W cm−2 at 500 °C were obtained.Here we report the fabrication of composite cathodes for reduced-temperature solid oxide fuel cells by impregnating aqueous solutions corresponding to SmBa0.5Sr0.5Co2O5 (SBSCO) into the porous La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM) backbones. Examination of X-Ray diffraction patterns indicates that phase-pure SBSCO layered perovskite oxides can be only achieved at calcination temperatures ≥900 °C. Based upon impedance measurement of symmetric cells, the SBSCO–LSGM composites calcinated at 850 °C show a trade-off between the SBSCO phase purity and catalyst size, and thereby exhibit minimal cathode polarization resistances with respect to the infiltrate calcination temperature, e.g., 0.035 Ω cm2 at 550 °C and 0.12 Ω cm2 at 500 °C at the loadings of 21 wt%. Analysis of impedance spectra under varied oxygen partial pressures suggests that oxygen reduction reactions on the nano-scale SBSCO–LSGM composite are largely dominated by ionization of adsorbed oxygen atoms on the SBSCO surfaces. Thin LSGM electrolyte fuel cells with impregnated Ni anodes and SBSCO cathodes show high power densities of 1.5 W cm−2 at 600 °C and 0.70 W cm−2 at 500 °C.
Co-reporter:Yucun Zhou, Xuejiao Liu, Junliang Li, Huaiwen Nie, Xiaofeng Ye, Shaorong Wang, Zhongliang Zhan
Journal of Power Sources 2014 Volume 252() pp:164-168
Publication Date(Web):15 April 2014
DOI:10.1016/j.jpowsour.2013.12.020
•Novel metal-supported SOFCs are fabricated by tape casting and co-sintering.•LSFSc oxides are used as symmetric electrode catalysts by impregnation method.•Nano-scale LSFSc catalysts are highly active for electrodes reactions.This paper reports on the fabrication of novel metal-supported solid oxide fuel cells containing porous 430L stainless steel substrates, YSZ electrolytes and porous YSZ cathode backbones. Such tri-layer structures are obtained by the tape casting, lamination and co-firing techniques. Redox-stable La0.6Sr0.4Fe0.9Sc0.1O3−δ (LSFSc) oxides are introduced as symmetric electrode catalysts onto the internal surfaces of porous 430L substrates and YSZ backbones using the solution impregnation method. The maximum power density is 0.65 W cm−2 measured at 800 °C. Impedance analyses show that the anode polarizations are the largest losses while the cathode polarizations make negligible contribution to the total cell resistances.
Co-reporter:Yucun Zhou, Xie Meng, Chun Yuan, Ting Luo, Xiaofeng Ye, Junliang Li, Shaorong Wang, Zhongliang Zhan
Journal of Power Sources 2014 Volume 269() pp:244-249
Publication Date(Web):10 December 2014
DOI:10.1016/j.jpowsour.2014.06.092
Co-reporter:Ting Chen, Yucun Zhou, Chun Yuan, Minquan Liu, Xie Meng, Zhongliang Zhan, Changrong Xia, Shaorong Wang
Journal of Power Sources 2014 Volume 269() pp:812-817
Publication Date(Web):10 December 2014
DOI:10.1016/j.jpowsour.2014.07.073
•Novel Nd2NiO4+δ-SSZ composite cathode is prepared.•Impregnated Nd2NiO4+δ cathode shows a low ASR of 0.04 Ω cm2 at 800 °C.•Maximum power density of 1.26 W cm−2 is obtained at 800 °C for IT-SOFCs.Here we developed a novel Nd2NiO4+δ (NNO) impregnated SSZ composite cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). The area specific polarization resistance of the composite cathode for oxygen reduction can be as low as 0.04 Ω cm2 at 800 °C. The anode supported SOFC with the structure of Ni-YSZ anode, SSZ electrolyte and impregnated NNO-SSZ composite cathode was prepared by the tape casting, co-firing and impregnation method. The resulting fuel cell exhibits maximum power densities of 1.26 and 0.73 W cm−2 at 800 and 700 °C, respectively when operated in hydrogen and air. Additionally, the electrical conductivity of the NNO cathode and the chemical compatibility with the electrolyte material were also studied.
Co-reporter:Chun Yuan, Xiaofeng Ye, Youpeng Chen, Ting Chen, Minquan Liu, Junliang Li, Zhongliang Zhan, Shaorong Wang
Electrochimica Acta 2014 Volume 149() pp:212-217
Publication Date(Web):10 December 2014
DOI:10.1016/j.electacta.2014.10.068
Anode-supported tubular solid oxide fuel cells (SOFCs) fabricated by traditional method suffered from the charge exchange constraint on the interface of electrolyte and cathode. In this work, we introduced a new sintering process to obtain the dense and porous electrolyte bi-layer structure on anode-supported tubular SOFCs. The cathode was built by infiltrating nano-catalyst La0.6Sr0.4Fe0.9Sc0.1O3-δ (LSFSc) into the porous electrolyte, which showed better electrochemical activity than traditional LSM cathode. The functional fuel cells showed the maximum power density of 292.3mW·cm−2 at 800 °C with H2 as fuel and air as oxidant. This unique performance was due to the porous electrolyte provided more specific surface area for cathode and the nanostructured cathode catalyst showed high electro-catalysis for oxygen reduction reaction. Moreover, a long term test was carried out, demonstrating the excellent stability which was extremely important for application in the future.
Co-reporter:Yucun Zhou, Da Han, Chun Yuan, Minquan Liu, Ting Chen, Shaorong Wang, Zhongliang Zhan
Electrochimica Acta 2014 Volume 149() pp:231-236
Publication Date(Web):10 December 2014
DOI:10.1016/j.electacta.2014.10.067
•Infiltrated SmBa0.5Sr0.5Co2O5+δ cathode for MS–SOFC is evaluated.•Polarization resistance of the cathode is 0.054 Ω cm2 at 700 °C.•No degradation is found after the 35 thermal cycles for the cathode.•Power density output of the fuel cell can be as high as 1.25 W cm−2 at 700 °C.This paper reports the fabrication of the SmBa0.5Sr0.5Co2O5+δ (SBSCO) infiltrated scandia–stabilized–zirconia (SSZ) composite cathode for metal–supported solid oxide fuel cells (MS–SOFCs). The effects of the calcination temperature on the structure, morphology and polarization resistance of the composite cathode were studied. Cathode calcinated at 700 °C showed the finest microstructure and the lowest polarization resistance, e.g., 0.054 and 0.172 Ω cm2 at 700 and 600 °C, respectively. Thermal shock resistance of the composite cathode was studied and no degradation was found after the 35 thermal cycles conducted between 100 and 600 °C with a rate of 10 °C min−1. MS–SOFC with the SBSCO infiltrated SSZ cathode was prepared and the maximum power density (MPD) can be as high as 1.25, 0.92, 0.61 and 0.39 W cm−2 when measured at 700, 650, 600 and 550 °C, respectively.
Co-reporter:Da Han, Yadi Liu, Shaorong Wang, Zhongliang Zhan
Electrochimica Acta 2014 Volume 143() pp:168-174
Publication Date(Web):10 October 2014
DOI:10.1016/j.electacta.2014.07.153
Here, first time, Pr0.6Sr0.4FeO3-Ce1-xPrxO2 (x = 0.1, 0.3, 0.5, 0.7, 0.9) dual-phase composites are co-infiltrated into the porous La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) skeletons to form composite cathodes and are used for low temperature solid oxide fuel cell (SOFC). By optimizing mass ratios of Pr0.6Sr0.4FeO3/Ce1-xPrxO2 and doping contents of Pr in the Pr0.6Sr0.4FeO3-Ce1-xPrxO2 composites, the lowest polarization resistance (Rp) recorded at 550 °C is achieved as 0.246 Ωcm2 for the 50wt%Pr0.6Sr0.4FeO3-50wt% Ce0.1Pr0.9O2-LSGM composite cathode. Reduction of both chemical resistance and charge transfer resistance are proved to be responsible for the performance improvement. Thermal cycling test reveals a performance degradation of only 4.6% for the 50wt%Pr0.6Sr0.4FeO3-50wt% Ce0.1Pr0.9O2-LSGM composite cathode after five thermal cycles, thereby showing a good thermal expansion match between the 50wt%Pr0.6Sr0.4FeO3-50wt%Ce0.1Pr0.9O2 composite and the LSGM skeleton. A functional fuel cell with infiltrated Ni/Ce0.8Sm0.2O2 (Ni/SDC) as anode and infiltrated 50wt%PSF-50wt% Ce0.9Pr0.1O2 as cathode shows the maximum power densities of 1.172, 0.916, 0.519 and 0.196 Wcm−2 at 600, 550, 500 and 450 °C, respectively. The cell operates at 550 °C with an almost constant current density of 1.087A/cm2 at 0.7 V for 50 h, demonstrating good stability.
Co-reporter:Chun Yuan, Ting Luo, Junliang Li, Xie Meng, Jiqin Qian, Xiaofeng Ye, Zhongliang Zhan, Changrong Xia, Shaorong Wang
Electrochemistry Communications 2014 Volume 46() pp:40-43
Publication Date(Web):September 2014
DOI:10.1016/j.elecom.2014.05.031
•New cathode-supported SOFCs were fabricated by tape-casting and co-sintering.•Infiltrated La0.6Sr0.4Fe0.9Sc0.1O3- nano-scale catalyst worked as active cathode.•The power density of new designed cathode-supported SOFCs was favorable.A novel active cathode structure of La0.6Sr0.4Fe0.9Sc0.1O3 − δ (LSFSc) infiltrated porous 8 mol% Y2O3-stabilized ZrO2 (YSZ) was fabricated by tape casting, co-sintering and infiltration techniques. The infiltrated porous-YSZ layer worked as a cathode active layer (CAL) between a YSZ electrolyte layer and (La0.8Sr0.2)0.95MnO3 (LSM95) cathode substrate. The obtained fuel cells with Ni/SDC anode showed the maximum power densities of 0.574, 0.733 and 0.835 W·cm− 2 at 750, 800 and 850 °C, respectively, with H2 as fuel and air as the oxidant.
Co-reporter:Zhenyi Zhou, Da Han, Hao Wu, Shaorong Wang
International Journal of Hydrogen Energy 2014 Volume 39(Issue 5) pp:2274-2278
Publication Date(Web):4 February 2014
DOI:10.1016/j.ijhydene.2013.11.061
•A novel vacuum dip-coating method was adopted to form a dense thin electrolyte layer.•Sm0.5Sr0.5CoO3−δ/ScSZ composite cathode was fabricated by an infiltrating method.•The maximum power density of single cell reached 0.85 W cm−2 at 750 °C.A novel vacuum dip-coating method has been adopted to form a dense thin yttrium stabilized zirconia (YSZ) layer on the pre-fired Ni/YSZ anode substrate. Scandia-stabilized Zirconia (ScSZ) was screen-printed onto the YSZ layer as the cathode backbone material and co-fired in a single step. Sm0.5Sr0.5CoO3−δ (SSC) nanoparticles were infiltrated into the ScSZ porous layer with a loading of 29.17wt% to gain the composite cathode. Without any optimization, the cell reached a maximum power density of 0.85 W cm−2 with an area-specific resistance of 0.914 Ω cm2 at 750 °C.
Co-reporter:Yucun Zhou, Xianshuang Xin, Junliang Li, Xiaofeng Ye, Changrong Xia, Shaorong Wang, Zhongliang Zhan
International Journal of Hydrogen Energy 2014 Volume 39(Issue 5) pp:2279-2285
Publication Date(Web):4 February 2014
DOI:10.1016/j.ijhydene.2013.11.086
•Metal-supported SOFCs are fabricated by tape casting and co-sintering.•Cell performance of 907 mW cm−2 at 800 °C is obtained.•Possible degradation mechanisms are investigated.Metal-supported solid oxide fuel cells (MS-SOFCs) containing porous 430L stainless steel supports, YSZ electrolytes and porous YSZ cathode backbones are fabricated by tape casting, laminating and co-firing in a reducing atmosphere. Nano-scale Ni and La0.6Sr0.4Fe0.9Sc0.1O3−δ (LSFSc) coatings are impregnated onto the internal surfaces of porous 430L and YSZ, acting as the anode and the cathode catalysts, respectively. The resulting MS-SOFCs exhibit maximum power densities of 193, 418, 636 and 907 mW cm−2 at 650, 700, 750 and 800 °C, respectively. Nevertheless, a continuous degradation in the fuel cell performance is observed at 650 °C and 0.7 V during a 200-h durability measurement. Possible degradation mechanisms were discussed in detail.
Co-reporter:Da Han, Yadi Liu, Shaorong Wang, Zhongliang Zhan
International Journal of Hydrogen Energy 2014 Volume 39(Issue 25) pp:13217-13223
Publication Date(Web):22 August 2014
DOI:10.1016/j.ijhydene.2014.06.123
•High performance functional fuel cells were fabricated by a novel replica technique combined with infiltrating process.•Maximum power densities of 1.8 W cm−2, 1 W cm−2, 0.38 W cm−2 and 0.12 W cm−2 at 550 °C, 500 °C, 450 °C and 400 °C were obtained.•An almost constant current density of 1.14 A/cm2 at 500 °C was achieved when discharged at 0.7 V for 80 h.For the convenience of hermetic sealing, first time, a replica technique is successfully invented in this study to fabricate the dissymmetrical tri-layer structure of “porous La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) |dense LSGM| porous LSGM” skeleton by adopting a carbon layer. SEM analysis reveals that the bonding strength of interfacial contact between dense LSGM and porous LSGM can also be improved when using this new fabrication method. Metal Ni and layered perovskite oxide SmBa0.5Sr0.5Co2O5 (SBSCO) are then infiltrated into the dissymmetrical skeleton on each side to form the functional fuel cell. The OCV are close to the expected Nernst potentials which demonstrate that the cell fabricated in this study can be well sealed. The maximum power densities of functional fuel cell with configuration of “Ni–LSGM |LSGM| LSGM–SBSCO” are 0.12 W cm−2, 0.38 W cm−2, 1 W cm−2 and 1.8 W cm−2 at 400, 450, 500, 550 °C, respectively. Though long term stability testing shows a rapid performance degradation when discharged at 0.7 V for 80 h, by changing pure Ni to Ni–SDC mixed oxide, the performance of functional fuel cell with configuration of “Ni–SDC–LSGM |LSGM| LSGM–SBSCO” increases and the long term stability is largely improved.
Co-reporter:Chun Yuan, Yadi Liu, Yucun Zhou, Zhongliang Zhan, Shaorong Wang
International Journal of Hydrogen Energy 2013 Volume 38(Issue 36) pp:16584-16589
Publication Date(Web):13 December 2013
DOI:10.1016/j.ijhydene.2013.08.146
•Cathode-support SOFCs were fabricated by tape-casting, lamination and co-sintering.•Weight ratio of pore-former was optimized by investigating the performance of symmetrical cells.•The pore size distribution and porosity of cathode-support substrate were measured.•Single cell was obtained to evaluate the properties of half cathode-support cell.(La0.8Sr0.2)0.95MnO3 (LSM95) cathode supported Zr0.89Sc0.1Ce0.01O2−x (SSZ) electrolytes with LSM-SSZ active cathode layers were fabricated using the tape-casting, lamination and co-sintering techniques. The loadings of pore-formers in the cathode support layers and the active cathode layers were optimized through impedance measurement on symmetrical cathode fuel cells. The pore size distribution and porosity of cathode-support substrates were measured using the mercury intrusion porosimetry. The open circuit voltage and maximum power density of cathode-support solid oxide fuel cells with NiO/SSZ cermet anodes were 1.10 V and 0.325 W cm−2 at 750 °C with H2 as fuels and air as oxidants.
Co-reporter:Le Shao, Shaorong Wang, Jiqin Qian, Xiaofeng Ye, Tinglian Wen
International Journal of Hydrogen Energy 2013 Volume 38(Issue 11) pp:4272-4280
Publication Date(Web):15 April 2013
DOI:10.1016/j.ijhydene.2012.12.144
Hydrogen electrode-supported tubular solid oxide cells (SOCs) were fabricated by dip-coating and co-sintering method. The electrochemical properties of tubular SOCs were investigated both in fuel cell and electrolysis modes. Ni-YSZ was employed as hydrogen electrode support. The pore ratio of Ni-YSZ support strongly affected the performance of tubular SOCs, especially in steam electrolysis mode. The pore ratio was adjusted by the content of pore-former in support slurry. The results showed that 3 wt.% pore former content is the proper value to produce high performance both in fuel cell and electrolysis modes. In fuel cell mode, the maximum power density reached 743.1 mW cm−2 with H2 (105 sccm) and O2 (70 sccm) as working gases at 850 °C. In electrolysis mode, as the electrolysis voltage was 1.3 V, the electrolysis current density reached 425 mA cm−2 with H2 (35 sccm) and N2 (70 sccm) adsorbed 47% steam as working gases in hydrogen electrode at 850 °C. The stability of tubular SOCs was related to the ratio of NiO/YSZ in the support. The sample with NiO/YSZ = 60/40 shows a better performance than the sample with NiO/YSZ = 50/50.Highlights► Tubular SOCs are fabricated by dip-coating and co-sintering method. ► Starch pore former addition into NiO-YSZ support changes the pore ratio of support. ► The cell with 3% pore-former exhibits the best performance. ► The stability of tubular SOCs is related to the NiO/YSZ ratio in support. ► The NiO/YSZ = 60/40 sample shows better stability than the 50/50 sample.
Co-reporter:Yadi Liu, Shaorong Wang, Jiqin Qian, Xianshuang Xin, Zhongliang Zhan, Tinglian Wen
International Journal of Hydrogen Energy 2013 Volume 38(Issue 32) pp:14053-14059
Publication Date(Web):25 October 2013
DOI:10.1016/j.ijhydene.2013.07.023
•La0.75Sr0.25Cr0.5−xFexMn0.5O3−δ nano-powders are synthesized by sol–gel process.•The maximum content of Fe doping is 0.2.•The materials show excellent chemical compatibility with YSZ.•The power density of the cell obtained in methane is comparative to that in hydrogen.•The sample sintered at 1300 °C exhibits higher electrochemical performance.The perovskite structured oxide La0.75Sr0.25Cr0.5−xFexMn0.5O3−δ (LSCFMx, x = 0.05, 0.1, 0.15, 0.2, 0.25) powder is prepared by the liquid phase method, using iron as dopant to replace the chromium. According to XRD patterns, perovskite-like LSCFMx are stable in pure H2, except for LSCFM0.25. Thus the maximum content of Fe doping is 0.2. The calculated lattice volume increases along with the content of iron and the powders show excellent chemical compatibility with yttria-stabilized zirconia (YSZ). The electrical conductivities for LSCFM0.15 and LSCFM0.2 are very comparative, and they exhibit similar performance as catalytic materials. In contrast, the different sintered temperature with the LSCFM0.2 catalytic layer, at 1300 °C exhibits higher electrochemical performance. When dry methane is used as the fuel, the ohmic resistance and polarization resistance are 0.15 and 0.55 Ω cm2, respectively, and the power density reaches 550 mW cm−2.
Co-reporter:Yucun Zhou, Zhencheng Zhang, Chun Yuan, Junliang Li, Changrong Xia, Zhongliang Zhan, Shaorong Wang
International Journal of Hydrogen Energy 2013 Volume 38(Issue 36) pp:16579-16583
Publication Date(Web):13 December 2013
DOI:10.1016/j.ijhydene.2013.02.068
Metal-supported solid oxide fuel cells (SOFCs) containing porous 430L stainless steel support, Ni-YSZ anode and YSZ electrolyte were fabricated by tape casting, laminating and co-firing in a reduced atmosphere. (Bi2O3)0.7(Er2O3)0.3–Ag composite cathode was applied by screen printing and in-situ sintering. The polarization resistances of the composite cathode were 1.18, 0.48, 0.18, 0.09 Ω cm2 at 600, 650, 700 and 750 °C, respectively. A promissing maximum power density of 568 mW cm−2 at 750 °C was obtained of the single cell. Short-term stability was measured as well.Highlights► Metal-supported SOFCs were fabricated by tape casting and co-firing. ► ESB–Ag composite cathode was applied by in-situ sintering. ► The polarization resistances of the composite cathode were measured. ► A promising electrochemical performance of the single cell was obtained.
Co-reporter:J. Zhou, X.F. Ye, L. Shao, X.P. Zhang, J.Q. Qian, S.R. Wang
Electrochimica Acta 2012 Volume 74() pp:267-270
Publication Date(Web):15 July 2012
DOI:10.1016/j.electacta.2012.04.080
A novel direct carbon fuel cell is designed and fabricated using cathode-supported tubular solid oxide fuel cell technology, which makes the research and optimization of fuel electrode much easier. The maximum power density of a SO-DCFC (solid oxide direct carbon fuel cell) single cell is 172.7 and 91.1 mW cm−2 at 900 and 850 °C, respectively, with carbon as the fuel humidified nitrogen to initiate reforming reactions. Results show that the cathode supported tubular design may have future promise.Graphical abstractHighlights► The novel direct carbon fuel cell is designed with the cathode-supported tubular SOFC. ► This kind of direct carbon fuel cell shows an extremely friendly structure. ► The maximum power density of the DCFC reaches 172.7 and 91.1 mW cm−2 at 900 and 850 °C, respectively. ► The results show a promising future of the cathode supported tubular design.
Co-reporter:Xiao-Feng Ye, J. Zhou, S.R. Wang, F.R. Zeng, T.L. Wen, Z.L. Zhan
International Journal of Hydrogen Energy 2012 Volume 37(Issue 1) pp:505-510
Publication Date(Web):January 2012
DOI:10.1016/j.ijhydene.2011.09.017
We have been researching Solid oxide fuel cells (SOFCs) with Cu-CeO2-ScSZ (scandia stabilized zirconia) anodes operating directly on ethanol fuels in recent years. In this paper, Cu-CeO2-ScSZ anodes with different Cu/CeO2 composition are fabricated by dry pressing, sintering and wet impregnation technologies. The photographs and SEM images of these samples after exposure to ethanol fuels for 300 h are observed to characterize their carbon deposition behaviors. The different deposited carbon morphologies in the anodes with different compositions are recorded, and possible reaction mechanisms and prevention methods are discussed. Based on these results; we demonstrate the carbon deposition behaviors and degradation reasons for the single cell running in ethanol fuels.Highlights► The deposited carbon morphologies in Cu-CeO2-ScSZ anodes were recorded. ► Several strategies were provided to prevent carbon deposition. ► These results help to justify whether there are carbon depositions in the anodes. ► Co and Ni were added to improve anode performances.
Co-reporter:Chuan Wang, Xianshuang Xin, Yanjie Xu, Xiaofeng Ye, Lijun Yu, Shaorong Wang, Tinglian Wen
Journal of Power Sources 2011 Volume 196(Issue 8) pp:3841-3845
Publication Date(Web):15 April 2011
DOI:10.1016/j.jpowsour.2010.12.099
The electrochemical performance of LSM–Pd composite material as current collector of SOFC cathode is studied on (La0.8Sr0.2)0.9MnO3 (LSM90) cathode. The influence of Pd content on contact resistance is investigated. The investigation shows that the contact resistance of LSM–Pd is about 20 mΩ cm2 at 750 °C when the composite contains 8 wt% Pd, and it could be comparable to pure Pt. The ohmic resistance of a single cell using LSM–Pd composite is about 255 mΩ cm2 that contains 4 wt% Pd as current collector, this value is close to that of a cell using expensive Pt paste as current collector.Research highlights▶ Pd connects LSM particles well. ▶ Pd–LSM composite has a good electrical conductivity. ▶ Current collection layer reduces the contact resistance.
Co-reporter:Yanjie Xu, Shaorong Wang, Renzhu Liu, Tinglian Wen, Zhaoyin Wen
Journal of Power Sources 2011 Volume 196(Issue 3) pp:1338-1341
Publication Date(Web):1 February 2011
DOI:10.1016/j.jpowsour.2010.07.088
Considering that conventional lanthanum chromate (LaCrO3) interconnector is hard to be co-sintered with green anode, we have fabricated a novel bilayered interconnector which consists of La-doped SrTiO3 (Sr0.6La0.4TiO3) and Sr-doped lanthanum manganite (La0.8Sr0.2MnO3). Sr0.6La0.4TiO3 is conductive and stable in reducing atmosphere, locating on the anode side; while La0.8Sr0.2MnO3 is on the cathode side. A slurry-brushing and co-sintering method is applied: the Sr0.6La0.4TiO3 and La0.8Sr0.2MnO3 slurries are successively brushed onto green anode specimen, followed by co-firing course to form a dense bilayered Sr0.6La0.4TiO3/La0.8Sr0.2MnO3 interconnector. For operating with humidified hydrogen and oxygen at 900 °C, the ohmic resistances between anode and cathode/interconnector are 0.33 Ω cm2 and 0.186 Ω cm2, respectively. The maximum power density is 290 mW cm−2 for a cell with interconnector, and 420 mW cm−2 for a cell without it, which demonstrates that nearly 70% of the power output can be achieved using this bilayered Sr0.6La0.4TiO3/La0.8Sr0.2MnO3 interconnector.
Co-reporter:Xiao-Feng Ye, S.R. Wang, J. Zhou, F.R. Zeng, H.W. Nie, T.L. Wen
Journal of Power Sources 2011 Volume 196(Issue 13) pp:5499-5502
Publication Date(Web):1 July 2011
DOI:10.1016/j.jpowsour.2010.09.053
A Ni–yttria-stabilized zirconia (YSZ) anode and a Cu–CeO2/Ni–YSZ multi-layer anode have been fabricated for use in anode-supported Solid Oxide Fuel Cells (SOFCs), and their performances and stabilities in H2–CO syngas have been studied at 750 °C. A high CO content has been found to cause carbon deposition and crack formation in the Ni–YSZ anode after long-term operation, but the Cu–CeO2 catalyst layer on the Ni–YSZ anode surface improves its stability in syngas with high CO content by facilitating the water gas shift reaction. The optimized single cell has run in syngas with a composition of 48.5%H2–48.5%CO–3%H2O for 460 h without obvious degradation of its performance, however, its performance decreases after 630 h due to carbon deposition in the anode functional layer and subsequent crack formation on the anode and electrolyte.
Co-reporter:Yanjie Xu, Shaorong Wang, Le Shao, Tinglian Wen, Zhaoyin Wen
International Journal of Hydrogen Energy 2011 Volume 36(Issue 10) pp:6194-6198
Publication Date(Web):May 2011
DOI:10.1016/j.ijhydene.2011.01.084
Two anode-supported tubular solid oxide fuel cells (SOFCs) have been connected by a co-sintered ceramic interconnector to form a stack. This novel bilayered ceramic interconnector consists of La-doped SrTiO3 (La0.4Sr0.6TiO3) and Sr-doped lanthanum manganite (La0.8Sr0.2MnO3), which is fabricated by co-sintering with green anode at 1380 °C for 3 h. La0.4Sr0.6TiO3 (LST) acts as a barrier avoiding the outward diffusion of H2 to the cathode; while La0.8Sr0.2MnO3 (LSM) prevents O2 from diffusing inward to the anode. The compatibility of LST and LSM, as well as their microstructure which co-sintered with anode are both studied. The resistances between anode and LST/LSM interconnector at different temperatures are determined by AC impedance spectra. The results have showed that the bilayered LST/LSM is adequate for SOFC interconnector application. The active area is 2 cm2 for interconnector and 16 cm2 for the total cathode of the stack. When operating at 900 °C, 850 °C, 800 °C with H2 as fuel and O2 as oxidant, the maximum power density of the stack are 353 mW cm−2, 285 mW cm−2 and 237.5 mW cm−2, respectively, i.e., approximately 80% power output efficiency can be achieved compared with the total of the two single cells.Highlights► A novel bilayered interconnector fabricated by co-sintering with green anode. ► Very cost-effective. ► Demonstration of a two-cell stack using this novel interconnector. ► 80% Power-Output efficiency of the stack.
Co-reporter:Chuan Wang, Xianshuang Xin, Yanjie Xu, Jianyin Chen, Le Shao, Juan Zhou, Shaorong Wang, Tinglian Wen
International Journal of Hydrogen Energy 2011 Volume 36(Issue 13) pp:7683-7687
Publication Date(Web):July 2011
DOI:10.1016/j.ijhydene.2011.03.127
A new system, (La0.8Sr0.2)1−xAgxMnO3+δ (LSAM, x ≤ 0.2), is developed as current collector for solid oxide fuel cell (SOFC). LSAM is prepared by a modified sol–gel method and presents a single phase. The shrinkage temperature reduces from 1150 °C to 800 °C with an addition of 15 mol% Ag to La0.8Sr0.2MnO3+δ (LSM20). The contact resistance between the current collector and the cathode is measured, and the influence of Ag content on the contact resistance is investigated. The result shows that the contact resistance using (La0.8Sr0.2)0.85Ag0.15MnO3+δ (LSAM15) as current collector is about 12 mΩ cm2 at 750 °C, which is close to the value using expensive Pt paste as current collector. This new system is a promising current collecting material for the practical application of SOFC.Highlights► Silver doped LSM greatly reduce the sintering temperature. ► The contact resistance of LSAM15 is about 12 mΩ cm2. ► Current collection layer reduces the contact resistance. ► The stability of LSAM is also good.
Co-reporter:J. Zhou, X.F. Ye, J.L. Li, S.R. Wang, T.L. Wen
Solid State Ionics 2011 Volume 201(Issue 1) pp:81-86
Publication Date(Web):19 October 2011
DOI:10.1016/j.ssi.2011.07.014
Apatite silicates have recently been reported as promising electrolyte materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). In this work, a series of apatite-type compounds La9.67Si6-xAlxO26.5-x/2 (LSAO) with x = 0–2 are synthesized by the sol–gel process at calcining temperature of 800–900 °C. Thermal expansion coefficient, relative density and electrical conductivity of these samples with different Al doped contents are investigated. A symmetrical cell, which is composed of La9.67Si5AlO26 electrolyte and (La0.74Bi0.10Sr0.16)MnO3+δ (LBSM) cathode, is fabricated and electrochemically characterized. LBSM cathode shows a good electrochemical performance, which proves LBSM to be a promising candidate cathode for LSAO-based electrolyte.Highlights► The series of apatite-phase compounds La9.67Si6-xAlxO26.5-x/2 were synthesized. ► The properties of these samples with different Al doped contents were investigated. ► Symmetrical cells with (La0.74Bi0.10Sr0.16)MnO3+ä (LBSM) cathode were fabricated. ► LBSM was found to be a promising candidate cathode for LSAO-base electrolyte.
Co-reporter:Guoqiang Cai;Renzhu Liu;Chunhua Zhao
Journal of Solid State Electrochemistry 2011 Volume 15( Issue 1) pp:147-152
Publication Date(Web):2011 January
DOI:10.1007/s10008-010-1079-8
The 70 wt.% Mn-doped CeO2 (MDC)-30 wt.% Scandia-stabilized zirconia (ScSZ) composites are evaluated as anode materials for solid oxide fuel cells (SOFCs) in terms of chemical compatibility, thermal expansion coefficient, electrical conductivity, and fuel cell performance in H2 and CH4. The conductivity of MDC10 (10 mol.% Mn-doping), MDC20, and CeO2 are 4.12, 2.70, and 1.94 S cm−1 in H2 at 900 °C. With 10 mol.% Mn-doping, the fuel cells performances improve from 166 to 318 mW cm−2 in H2 at 900 °C. The cell with MDC10–ScSZ anode exhibits a better performance than the one with MDC20–ScSZ in CH4, the maximum power density increases from 179 to 262 mW cm−2. Electrochemical impedance spectra indicate that the Mn doping into CeO2 can reduce the ohmic and polarization resistance, thus leading to a higher performance. The results demonstrate the potential ability of MDC10–ScSZ composite to be used as SOFCs anode.
Co-reporter:Xiao-Feng Ye, S.R. Wang, J. Zhou, F.R. Zeng, H.W. Nie, T.L. Wen
Journal of Power Sources 2010 Volume 195(Issue 21) pp:7264-7267
Publication Date(Web):1 November 2010
DOI:10.1016/j.jpowsour.2010.04.016
Anode-supported Solid Oxide Fuel Cells (SOFCs) with Ni-yttria-stabilized zirconia (YSZ) anode have been fabricated and studied using H2–CO syngas fuels. Syngas fuels with different compositions of H2–CO are supplied and the cell performance is measured at 750 °C. A high CO content has caused carbon deposition and crack formation in the Ni-YSZ anode after long-term operation, even though it is diluted with H2O and N2. However, it was found that a Cu–CeO2 coating on Ni-YSZ can greatly improve the anode stability in syngas by facilitating the water gas shift reaction. The optimized single cell has run in sygas with a composition of 65%H2–32%CO–3%H2O for 1050 h without obvious degradation of its performance.
Co-reporter:Renzhu Liu, Chunhua Zhao, Junliang Li, Fanrong Zeng, Shaorong Wang, Tinglian Wen, Zhaoyin Wen
Journal of Power Sources 2010 Volume 195(Issue 2) pp:480-482
Publication Date(Web):15 January 2010
DOI:10.1016/j.jpowsour.2009.07.032
A direct carbon fuel cell based on a conventional anode-supported tubular solid oxide fuel cell, which consisted of a NiO–YSZ anode support tube, a NiO–ScSZ anode functional layer, a ScSZ electrolyte film, and a LSM–ScSZ cathode, has been successfully achieved. It used the carbon black as fuel and oxygen as the oxidant, and a preliminary examination of the DCFC has been carried out. The cell generated an acceptable performance with the maximum power densities of 104, 75, and 47 mW cm−2 at 850, 800, and 750 °C, respectively. These results demonstrate the feasibility for carbon directly converting to electricity in tubular solid oxide fuel cells.
Co-reporter:Renzhu Liu, Chunhua Zhao, Junliang Li, Shaorong Wang, Zhaoyin Wen, Tinglian Wen
Journal of Power Sources 2010 Volume 195(Issue 2) pp:541-545
Publication Date(Web):15 January 2010
DOI:10.1016/j.jpowsour.2009.06.099
We have studied the properties of a cathode fabricated by painting with a brush pen for use with anode-supported tubular solid oxide fuel cells (SOFCs). The porous cathode connects well with the electrolyte. A preliminary examination of a single tubular cell, consisting of a Ni–YSZ anode support tube, a Ni–ScSZ anode functional layer, a ScSZ electrolyte film, and a LSM–ScSZ cathode fabricated by painting with a brush pen, has been carried out, and an improved performance is obtained. The ohmic resistance of the cathode side clearly decreases, falling to a value only 37% of that of the comparable cathode made by dip-coating at 850 °C. The single cell with the painted cathode generates a maximum power density of 405 mW cm−2 at 850 °C, when operating with humidified hydrogen.
Co-reporter:Renzhu Liu, Chunhua Zhao, Junliang Li, Guoqiang Cai, Shaorong Wang, Tinglian Wen, Zhaoyin Wen
Electrochimica Acta 2010 Volume 55(Issue 6) pp:2134-2138
Publication Date(Web):15 February 2010
DOI:10.1016/j.electacta.2009.11.046
We have adopted three different methods: dip-coating, brush pen painting, and ion-impregnating, to fabricate cathodes for anode-supported tubular solid oxide fuel cells; and studied the performances of the cells using cathodes fabricated by these three different methods. The cell with ion-impregnated cathode presented the best electrochemical performances in these three cells, and it generated a maximum power density of 446 mW cm−2 at 850 °C, when operating with humidified hydrogen. The cells with dip-coated cathode and brush pen painted cathode produced acceptable electrochemical performances; they generated maximum power densities of 403 and 405 mW cm−2 at 850 °C, respectively, when running on humidified hydrogen; also, they represented more stable, much easier processes and lower cost.
Co-reporter:Junliang Li;Zhenrong Wang
Journal of Solid State Electrochemistry 2010 Volume 14( Issue 4) pp:579-583
Publication Date(Web):2010 April
DOI:10.1007/s10008-009-0813-6
The study elementarily investigated the effect of the cathode structure on the electrochemical performance of anode-supported solid oxide fuel cells. Four single cells were fabricated with different cathode structures, and the total cathode thickness was 15, 55, 85, and 85 µm for cell-A, cell-B, cell-C, and cell-D, respectively. The cell-A, cell-B, and cell-D included only one cathode layer, which was fabricated by \( \left( {{\text{La}}_{0.74} {\text{Bi}}_{0.10} {\text{Sr}}_{0.16} } \right){\text{MnO}}_{{3 - \delta }} \) (LBSM) electrode material. The cathode of the cell-C was composed of a \( \left( {{\text{La}}_{0.74} {\text{Bi}}_{0.10} {\text{Sr}}_{0.16} } \right){\text{MnO}}_{{3 - \delta }} - \left( {{\text{Bi}}_{0.7} {\text{Er}}_{0.3} {\text{O}}_{1.5} } \right) \) (LBSM–ESB) cathode functional layer and a LBSM cathode layer. Different cathode structures leaded to dissimilar polarization character for the four cells. At 750°C, the total polarization resistance (Rp) of the cell-A was 1.11, 0.41 and 0.53 Ω cm2 at the current of 0, 400, and 800 mA, respectively, and that of the cell-B was 1.10, 0.39, and 0.23 Ω cm2 at the current of 0, 400, and 800 mA, respectively. For cell-C and cell-D, their polarization character was similar to that of the cell-B and Rp also decreased with the increase of the current. The maximum power density was 0.81, 1.01, 0.79, and 0.43 W cm−2 at 750°C for cell-D, cell-C, cell-B, and cell-A, respectively. The results demonstrated that cathode structures evidently influenced the electrochemical performance of anode-supported solid oxide fuel cells.
Co-reporter:Junliang Li, Shaorong Wang, Zhenrong Wang, Renzhu Liu, Tinglian Wen, Zhaoyin Wen
Journal of Power Sources 2009 Volume 194(Issue 2) pp:625-630
Publication Date(Web):1 December 2009
DOI:10.1016/j.jpowsour.2009.06.070
La0.84Sr0.16MnO3−δ–Bi1.4Er0.6O3 (LSM–ESB) composite cathodes are fabricated by impregnating LSM electronic conducting matrix with the ion-conducting ESB for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The performance of LSM–ESB cathodes is investigated at temperatures below 750 °C by AC impedance spectroscopy. The ion-impregnation of ESB significantly enhances the electrocatalytic activity of the LSM electrodes for the oxygen reduction reactions, and the ion-impregnated LSM–ESB composite cathodes show excellent performance. At 750 °C, the value of the cathode polarization resistance (Rp) is only 0.11 Ω cm2 for an ion-impregnated LSM–ESB cathode, which also shows high stability during a period of 200 h. For the performance testing of single cells, the maximum power density is 0.74 W cm−2 at 700 °C for a cell with the LSM–ESB cathode. The results demonstrate the ion-impregnated LSM–ESB is one of the promising cathode materials for intermediate-temperature solid oxide fuel cells.
Co-reporter:Chunhua Zhao, Renzhu Liu, Shaorong Wang, Zhenrong Wang, Jiqin Qian, Tinglian Wen
Journal of Power Sources 2009 Volume 192(Issue 2) pp:552-555
Publication Date(Web):15 July 2009
DOI:10.1016/j.jpowsour.2009.03.019
A cathode-supported tubular solid oxide fuel cell (CTSOFC) with the length of 6.0 cm and outside diameter of 1.0 cm has been successfully fabricated via dip-coating and co-sintering techniques. A crack-free electrolyte film with a thickness of ∼14 μm was obtained by co-firing of cathode/cathode active layer/electrolyte/anode at 1250 °C. The relative low densifying temperature for electrolyte was attributed to the large shrinkage of the green tubular which assisted the densification of electrolyte. The assembled cell was electrochemically characterized with humidified H2 as fuel and O2 as oxidant. The open circuit voltages (OCV) were 1.1, 1.08 and 1.06 V at 750, 800 and 850 °C, respectively, with the maximum power densities of 157, 272 and 358 mW cm−2 at corresponding temperatures.
Co-reporter:Junliang Li, Shaorong Wang, Zhenrong Wang, Renzhu Liu, Xiaofeng Ye, Xiufu Sun, Tinglian Wen, Zhaoyin Wen
Journal of Power Sources 2009 Volume 188(Issue 2) pp:453-457
Publication Date(Web):15 March 2009
DOI:10.1016/j.jpowsour.2008.12.027
Porous composite cathodes were fabricated by impregnating (La0.74Bi0.10Sr0.16)MnO3−δ (LBSM) electronic conducting structure with the ionic conducting Ce0.8Gd0.2O2−δ (GDC) phase. The ion impregnation of the GDC phase significantly enhanced the electrocatalytic activity of the LBSM electrodes for the O2 reduction reactions, and the ion-impregnated LBSM–GDC composite cathodes showed excellent performance. At 700 °C, the value of the cathode polarization resistance (Rc) was only 0.097 Ω cm2 for an ion-impregnated LBSM–GDC cathode, and the performance was gradually improved by increasing the loading of the impregnated GDC. For the performance testing of single cells, the maximum power density was 1036 mW cm−2 at 700 °C for a cell with the LBSM–GDC cathode. The results demonstrated the unique combination of the LBSM electronic conducting structure with high ionic conducting GDC phase was a valid method to improve the electrode performance, and the ion-impregnated LBSM–GDC was a promising composite cathode material for the intermediate-temperature solid oxide fuel cells.
Co-reporter:Xiao-Feng Ye, S.R. Wang, Q. Hu, Z.R. Wang, T.L. Wen, Z.Y. Wen
Electrochemistry Communications 2009 Volume 11(Issue 4) pp:823-826
Publication Date(Web):April 2009
DOI:10.1016/j.elecom.2009.02.003
Anodes for Solid Oxide Fuel Cells (SOFCs) that are capable of directly using hydrocarbon fuels without external reforming have been of great interest in the recent years. We have fabricated a two-layer structure containing a Cu–CeO2 catalyst layer by tape casting and screen printing technology. The interface combination between the Cu–CeO2 catalyst layer and the Ni–YSZ-supported anode issues importantly for the stability of the anode structure. In this paper, a Ni–CeO2 interlayer was added between these two layers to improve the long-term stability of the multi-layer anode. Meanwhile, the exit gas of the single cell was also analyzed by a gas chromatographer (GC) to determine the reaction mechanism of the ethanol fuel in the anode.
Co-reporter:Chunhua Zhao, Renzhu Liu, Shaorong Wang, Tinglian Wen
Electrochemistry Communications 2009 Volume 11(Issue 4) pp:842-845
Publication Date(Web):April 2009
DOI:10.1016/j.elecom.2009.02.007
A large area cathode-supported electrolyte film, comprising porous (La0.8Sr0.2)0.95MnO3 (LSM95) cathode substrate, LSM95/Zr0.89Sc0.1Ce0.01O2−x (SSZ) cathode active layer, and SSZ electrolyte, has been successfully fabricated by tape casting and co-sintering techniques. The interface reaction between cathode and electrolyte was inhibited by using A-site deficient LSM. A dense enough SSZ thin film with a thickness of ∼26 μm was obtained at 1250 °C. By using Pt as anode, the obtained single cell reached the maximum power density of 0.54 W cm−2 at 800 °C in O2/humidified H2, with open circuit voltage (OCV) value of 1.08 V.
Co-reporter:Xiao-Feng Ye, S.R. Wang, Q. Hu, J.Y. Chen, T.L. Wen, Z.Y. Wen
Solid State Ionics 2009 Volume 180(2–3) pp:276-281
Publication Date(Web):9 March 2009
DOI:10.1016/j.ssi.2008.11.010
Ethanol is considered to be an attractive green fuel for solid oxide fuel cells (SOFCs) due to several advantages. In this paper, we presented recent progress of our group in Cu–CeO2 anodes for SOFCs with ethanol steam as a fuel. Cu–CeO2–ScSZ (scandia stabilized zirconia)anodes with different ratios of copper versus ceria were fabricated and the impedance spectra of symmetric cells were measured to optimize the anode composition. Area specific resistance (ASR) of these anodes was examined to prove the thermal stability of them, and possible reasons for degradation were analyzed. Furthermore, a Ni–ScSZ interlayer was added between Cu–CeO2–YSZ (yttria stabilized zirconia) anode and ScSZ electrolyte to improve the anode performance, and the three-layer structure was fabricated by acid leaching of nickel and wet impregnation method. The maximum power density of the single cell reached 604 mW cm− 2 and 408 mW cm− 2 at 800 °C in hydrogen and ethanol steam respectively, and the cell obtained stable output in ethanol steam over an operation period of 50 h.
Co-reporter:Xiao-Feng Ye, S.R. Wang, Z.R. Wang, Q. Hu, X.F. Sun, T.L. Wen, Z.Y. Wen
Journal of Power Sources 2008 Volume 183(Issue 2) pp:512-517
Publication Date(Web):1 September 2008
DOI:10.1016/j.jpowsour.2008.05.064
The perovskite system La1−xSrxCr1−yMyO3−δ (M, Mn, Fe and V) has recently attracted much attention as a candidate material for the fabrication of solid oxide fuel cells (SOFCs) due to its stability in both H2 and CH4 atmospheres at temperatures up to 1000 °C. In this paper, we report the synthesis of La0.75Sr0.25Cr0.5Mn0.5O3 (LSCM) by solid-state reaction and its employment as an alternative anode material for anode-supported SOFCs. Because LSCM shows a greatly decreased electronic conductivity in a reducing atmosphere compared to that in air, we have fabricated Cu-LSCM-ScSZ (scandia-stabilized zirconia) composite anodes by tape-casting and a wet-impregnation method. Additionally, a composite structure (support anode, functional anode and electrolyte) structure with a layer of Cu-LSCM-YSZ (yttria-stabilized zirconia) on the supported anode surface has been manufactured by tape-casting and screen-printing. Single cells with these two kinds of anodes have been fabricated, and their performance characteristics using hydrogen and ethanol have been measured. In the operation period, no obvious carbon deposition was observed when these cells were operated on ethanol. These results demonstrate the stability of LSCM in an ethanol atmosphere and its potential utilization in anode-supported SOFCs.
Co-reporter:Junliang Li, Shaorong Wang, Xiufu Sun, Renzhu Liu, Xiaofeng Ye, Zhaoyin Wen
Journal of Power Sources 2008 Volume 185(Issue 2) pp:649-655
Publication Date(Web):1 December 2008
DOI:10.1016/j.jpowsour.2008.09.012
Porous composite cathodes including (La0.74Bi0.10Sr0.16)MnO3−δ (LBSM) and Bi1.4Er0.6O3 (ESB) were fabricated and characterized using AC impedance spectroscopy. In our earlier work, the growth and aggregation of ESB particles were found in LBSM–ESB composite cathodes. In this study, therefore, two approaches were used to restrain the growth and aggregation of ESB particles. First, the sintering temperature of the composite cathode was reduced by introducing a sintering function layer, which caused a 22% reduction in the initial polarization resistance (R), but the cathode polarization resistance decreased at a rate of 2.15 × 10−4 Ω cm2 h−1 at 700 °C during a period of 100 h. Second, nano-sized Gd-doped ceria powder (CGO) was added to the composite cathode system. Stability improvement was achieved at 10 vol% CGO, and the degradation rate at 700 °C was 4.01 × 10−5 Ω cm2 h−1 during a period of 100 h.
Co-reporter:Junliang Li, Shaorong Wang, Zhengrong Wang, Renzhu Liu, Tinglian Wen, Zhaoyin Wen
Journal of Power Sources 2008 Volume 179(Issue 2) pp:474-480
Publication Date(Web):1 May 2008
DOI:10.1016/j.jpowsour.2008.01.017
(La0.74Bi0.10Sr0.16)MnO3−δ (LBSM)–(Bi2O3)0.7(Er2O3)0.3(ESB) composite cathodes were fabricated for intermediate-temperature solid oxide fuel cells with Sc-stabilized zirconia as the electrolyte. The performance of these cathodes was investigated at temperatures below 750 °C by AC impedance spectroscopy and the results indicated that LBSM–ESB had a better performance than traditional composite electrodes such as LSM–GDC and LSM–YSZ. At 750 °C, the lowest interfacial polarization resistance was only 0.11 Ω cm2 for the LBSM–ESB cathode, 0.49 Ω cm2 for the LSM–GDC cathode, and 1.31 Ω cm2 for the LSM–YSZ cathode. The performance of the cathode was improved gradually by increasing the ESB content, and the performance was optimal when the amounts of LBSM and ESB were equal in composite cathodes. This study shows that the sintering temperature of the cathode affected performance, and the optimum sintering temperature for LBSM–ESB was 900 °C.
Co-reporter:Xiao-Feng Ye, S.R. Wang, Z.R. Wang, L. Xiong, X.F. Sun, T.L. Wen
Journal of Power Sources 2008 Volume 177(Issue 2) pp:419-425
Publication Date(Web):1 March 2008
DOI:10.1016/j.jpowsour.2007.11.054
Solid oxide fuel cells (SOFCs) operating directly on hydrocarbon fuels have attracted much attention in recent years. A two-layer structure anode running on ethanol was fabricated by tape casting and screen printing technology in this paper, the addition of a Cu–CeO2 catalyst layer to the supported anode surface yielded much better performance in ethanol fuel. The effect that the synthesis conditions of the catalyst layer have on the performances of the composite anodes was investigated. Single cells with this anode were also fabricated, of which the maximum power density reached 566 mW cm−2 at 800 °C operating on ethanol steam. Long-term performance of the anodes was presented by discharging as long as 80 h without carbon deposition.
Co-reporter:Z.R. Wang, J.Q. Qian, S.R. Wang, J.D. Cao, T.L. Wen
Solid State Ionics 2008 Volume 179(27–32) pp:1593-1596
Publication Date(Web):30 September 2008
DOI:10.1016/j.ssi.2008.03.022
Anode-supported electrolyte composite membranes were prepared by a multilayer tape casting and co-sintering procedure. Nickel/yttria-stabilized zirconia (Ni/YSZ), nickel/scandia-stabilized zirconia (Ni/ScSZ) cermets, ScSZ, and Ce0.9Gd0.1O1.9 (CGO) were used as materials of anode substrate, anode functional layer, electrolyte and interlayer. After tape casting and dryness, the green tapes were co-sintered at 1350, 1400, and 1450 °C for 4 h in air. Then the LSCF-CGO composite cathode was deposited on the CGO surface by screen-printing and sintered at 1100 °C for 3 h. The performance of the anode-supported planar single SOFC was investigated in detail.In order to measure the AC impedance spectra, the symmetrical anode-supported cell design was used and also prepared by tape casting and co-sintering techniques.
Co-reporter:Junliang Li, Shaorong Wang, Renzhu Liu, Zhengrong Wang, J.Q. Qian
Solid State Ionics 2008 Volume 179(27–32) pp:1597-1601
Publication Date(Web):30 September 2008
DOI:10.1016/j.ssi.2007.12.088
The electrochemical performance of ESB [(Bi2O3)1 − x(Er2O3) x]–Ag composite material for IT-SOFC cathode was studied on the SSZ [(ZrO2)0.89(Sc2O3)0.1(CeO2)0.01] electrolyte. The influence of different ESB/Ag ratio and erbium-doped content on the performance of the composite cathode was investigated using AC impedance spectroscopy analysis. The investigation showed that there was a low polarization resistance (0.16 Ω cm2 to 0.50 Ω cm2 at temperatures from 750 °C to 650 °C) when the content of 3ESB [(Bi2O3)0.7(Er2O3)0.3] and Ag was equal in composite cathode.
Co-reporter:S. Wang, R. Zheng, A. Suzuki, T. Hashimoto
Solid State Ionics 2004 Volume 174(1–4) pp:157-162
Publication Date(Web):29 October 2004
DOI:10.1016/j.ssi.2004.07.029
Preparation, thermal expansion, electrical conductivity and polarization of La0.6Sr0.4Co1−xGaxO3−δ (LSCG) (x=0.0–0.4) were studied in order to estimate the potential as a new material for cathode of intermediate temperature solid oxide fuel cells (ITSOFC). Within x≦0.4, hexagonally distorted perovskite single phase of La0.6Sr0.4Co1−xGaxO3−δ was obtained. Thermal expansion coefficients (TEC) of the specimens with x<0.3 showed higher values than those of electrolyte materials, such as Ce0.8Gd0.2O1.9 or La0.8Sr0.2Ga0.85Mg0.15O2.825, whereas those of specimens with x=0.3 showed close value. The electrical conductivity decreased with increasing Ga content; however, the conductivity for x=0.4 is still in the order of 102 S/cm at 800 °C. Polarization measurements showed that cathode performance decreased with increasing Ga content; however, the sample with x=0.4 still has sufficient activity as a new cathode material of ITSOFC.
