排序方式: 共有8条查询结果,搜索用时 26 毫秒
1
1.
《International Journal of Hydrogen Energy》2020,45(53):29259-29270
Symmetrical solid oxide fuel cell (SSOFC) is a simple and very promising cell for the rest of the most important commercialization process, which has been longing for stable and efficient symmetrical electrodes, from single-phase perovskites to reducible perovskites with in-situ exsolved metal nanoparticles. Herein, we present a new-type hybrid symmetrical electrode consisting of two different perovskite phases for SSOFC, which interact by dynamic compositional change and accordingly improve the electrochemical activity. Furthermore, a simple Ce-doping strategy is successfully developed to solve the redox stability issue of the hybrid symmetrical electrode for SSOFC. Typical Gd0.65Sr0.35Co0.25Fe0.75O3-δ (GSCF) consisting of a cubic perovskite phase and an orthorhombic perovskite phase is chosen as a proof-of-concept. Gd0.65Sr0.35(Co0.25Fe0.75)0.9Ce0.1O3-δ (Ce-GSCF) with an optimized Ce content of only 10% exhibit the enhanced chemical and thermal stability, consisting of a cubic perovskite phase, an orthorhombic perovskite phase and an in-situ exsolved cubic fluorite phase (GDC). More importantly, Ce-GSCF exhibits very high stability in H2 at 700 °C and a dramatical reduction of averaged thermal expansion coefficient from 19.5 × 10−6 K−1 to 16.4 × 10−6 K−1. The single-cell with Ce-GSCF hybrid symmetrical electrode reaches a high maximum power density of 224 mW/cm2 at 700 °C, and can work stably for 180 h without any degradation, indicating that the simple Ce-doping strategy is promising to improve stability of hybrid symmetrical electrode for SOFCs. 相似文献
2.
《International Journal of Hydrogen Energy》2019,44(59):31333-31341
Symmetrical solid oxide fuel cell (SOFC) adopting the same material at both electrodes is potentially capable of promoting thermomechanical compatibility between near components and lowering stack costs. In this paper, MnCr2O4–Gd0.1Ce0.9O2-δ (MCO-GDC) composite electrodes prepared by co-infiltration method for symmetrical electrolyte supported and anode supported solid oxide fuel cells are evaluated at a temperature range of 650–800 °C in wet (3% H2O) hydrogen and air atmospheres. Without any alkaline earth elements and cobalt, the co-infiltrated MCO-GDC composite electrode shows excellent activity for oxygen reduction reaction but mediocre activity for hydrogen oxidation reaction. With MCO-GDC as the cathode, the Ni-YSZ (Y2O3 stabilized ZrO2) anode supported asymmetrical cell demonstrates a peak power density of 665 mW cm−2 at 800 °C. The above results suggest MCO-GDC is a promising candidate cathode material for solid oxide fuel cells. 相似文献
3.
《Journal of the European Ceramic Society》2022,42(1):181-192
Novel nanostructured electrodes, La0.98Cr0.75B0.25O3δ (B = Mn, Fe, Ti and Cu), are prepared by a single spray-pyrolysis deposition method directly on the electrolyte and a porous Ce0.9Gd0.1O1.95 (CGO) scaffold. These perovskite-type electrodes without alkaline-earth metals exhibit low ionic/electronic conductivity; however, the polarization resistance is greatly enhanced by microstructural design. The best results are obtained for La0.98Cr0.75Mn0.25O3-δ deposited into a porous CGO-scaffold due to the synergetic effect of CGO, with high ionic conductivity, and doped-LaCrO3 with a predominantly electronic conductivity. The materials are investigated as both air and fuel electrodes for solid oxide fuel cells (SOFCs) by different structural, microstructural and electrochemical techniques. Low values of polarization resistance are achieved for nanostructured La0.98Cr0.75Mn0.25O3-δ-CGO electrodes, i.e. 0.057 Ω cm2 in air at 800 °C, compared to 0.96 Ω cm2 for the same powder electrode obtained by screen-printing deposition. An electrolyte-supported symmetrical cell generates a stable maximum power output of 475 mW cm−2 at 800 °C. 相似文献
4.
《International Journal of Hydrogen Energy》2023,48(26):9812-9822
Symmetrical solid oxide fuel cells (S-SOFCs) have received considerable attention due to fewer preparation steps in recent years. The PrBaFe2O5+δ (PBF) is a candidate material due to good catalytic activity and electrochemical stability. In this work, Ta-substituted PBF materials (PrBaFe2-xTaxO5+δ, denoted as PBFTx, x = 0, 0.1, 0.2, 0.3) are prepared and evaluated as symmetrical electrodes on GDC(Gd0.1Ce0.9O2-δ)-YSZ(yttria-stabilized zirconia)-GDC three-layer electrolyte. The PrBaFe1.8Ta0.2O5+δ (PBFT0.2) symmetrical cell presents the lowest polarization resistance, and the value is 0.171 Ω cm2 and 0.503 Ω cm2 in air and hydrogen atmosphere at 800 °C, respectively. In addition, the PBFT0.2 cell shows a peak power density of 234 mW/cm2 using humidified hydrogen as fuel gas and air as oxidant at 800 °C, which is enhanced by 68% compared with that of PBF (138 mW/cm2). The results indicate that the strategy of Ta doping can improve the electrochemical performance of PBF and PBFT0.2 is a potential electrode for S-SOFCs. 相似文献
5.
D.A. Osinkin 《International Journal of Hydrogen Energy》2021,46(48):24546-24554
The electrochemical behaviour of a Sr2Fe1.5Mo0.5O6–δ based double-layer electrode decorated with a “symmetric” catalyst by the wet impregnation technique for the simultaneous acceleration of cathodic and anodic reactions was investigated for the first time. As a “symmetric” catalyst, a solution of precursor for the synthesis of praseodymium nickelate (Pr2NiO4+δ) was considered. Since the catalyst consists of NiO and Pr6O11 in an oxidizing atmosphere and of Ni and Pr2O3 in a reducing atmosphere, it effectively accelerates the rate of oxygen reduction at the cathode and hydrogen oxidation at the anode of solid oxide fuel cells with symmetric electrodes. It was shown that the rate of oxygen reduction after introduction of the catalyst into the electrode increased due to an increase in the rate of oxygen interfacial exchange between the electrode and the gas phase. The rate of hydrogen oxidation increased due to an increase in the rate of dissociation of adsorbed hydrogen. During tests of the fuel cell with a 300 μm LaGaO3-based supporting electrolyte and decorated electrodes, a maximum power density of about 0.83 W cm?2 at 800 °C under wet hydrogen/air condition was obtained. 相似文献
6.
7.
《International Journal of Hydrogen Energy》2019,44(59):31394-31405
Symmetrical solid oxide fuel cell (SSOFC) is one of efficient ways to simplify preparation process, reduce manufacturing cost, and improve redox stability and reliability. Here, we report the performance of Sr-deficient Sr1.9FeNb0.9Mo0.1O6-δ (SFNM) double perovskites as symmetrical electrodes for direct-hydrocarbon solid oxide fuel cells and significant improvement of electrochemical performance. The SFNM exhibits good structural stability, suitable thermal expansion coefficient and highly chemical compatibility with Sm0.2Ce0.8O1.9 (SDC) and La0.9Sr0.1Ga0.8Mg0.2O3–δ (LSGM) electrolytes in both air and 5% H2/Ar atmospheres. The area specific resistance of SFNM electrode is decreased by 3.6 and 8.4 times at 800 °C in air and H2, respectively, as compared to the pristine Sr2FeNbO6-δ electrode. The electrochemical performance is further improved by introducing a small amount of Pd to form Pd-impregnated SFNM composite electrode (Pd-SFNM). The SSOFCs with Pd-SFNM after two-time impregnation treatments as the electrodes achieve impressive electrochemical performances in different fuels. The Pd-SFNM symmetrical electrode reveals good electrochemical stability operating on CH4–CO2 mixed gas. 相似文献
8.
1