Xingbao Zhu

Direct Flame SOFCs with La(0.75)Sr(0.25)Cr(0.5)Mn(0.5)O(3-delta)/Ni Coimpregnated Yttria-Stabilized Zirconia Anodes Operated on Liquefied Petroleum Gas Flame

In the present study, the performances of a single solid oxide fuel cell (SOFC) and a micro-SOFC stack fueled with flame of combusting liquefied petroleum gas (LPG) were studied. La(0.75)Sr(0.25)Cr(0.5)Mn(0.5)O(3-delta) and Ni coimpregnated yttria-stabilized zirconia were used as the anode material of the direct-flame SOFC. The operation temperature of the cell can be sustained at 500-700 degrees C for the combustion of LPG. With the anode facing the LPG flame and the La(0.8)Sr(0.2)MnO(3-delta) cathode freely exposing to ambient air, the single cell exhibited an open-circuit voltage (OCV) of more than 0.85 V and the maximum power density (P(max)) of 238 mW/cm(2). The micro-SOFC stack with three single cells connected in series demonstrated an OCV of 2.5 V and the maximum power output of 64 mW (corresponding to a P(max) of 139 mW/cm(2)). The cell performance was found to be strongly influenced by the cell temperature. And the temperature is determined by cell position and gas composition. Additionally, the cell stability and carbon deposition after operation on the diffusion flame of the LPG were also tested

A preliminary study of the pseudo-capacitance features of strontium doped lanthanum manganite

The intrinsically poor electrical conductivity of transition metal oxides is a critical challenge to obtain high electrochemical performance when these materials are used as the electrode of supercapacitors. In this study, the pseudo-capacitance features of perovskite (La0.75Sr0.25)0.95MnO3−δ (LSM) having a high electric conductivity of 44.9 S cm−1 at room temperature was preliminarily investigated. The easily prepared LSM electrode was characterized by cyclic voltammetry and galvanostatic charge–discharge method to evaluate its electrochemical performances. The results show that LSM has pseudo-capacitance features and the specific capacitance is 56 F g−1 at a scanning rate of 2 mV s−1. This is the first report on the pseudo-capacitance value of LSM. Furthermore, the electrodes show no obvious capacitance degradation after 1000 cycles.

Impregnated La0.75Sr0.25Cr0.5Fe0.5O3―δ-Based Anodes Operating on H2, CH4, and C2H5OH Fuels

An aqueous impregnation method has been developed to incorporate La 0.75 Sr 0.25 Cr 0.5 Fe 0.5 O 3―δ NiO, and Sm-doped CeO 2 phases into a presintered porous yttria-stabilized zirconia (YSZ) anode matrix to form an effective LSCrFe + NiO + SDC + YSZ composite anode, in which the well-sintered YSZ provides a highly connected ion-conducing pathway while a small amount of Ni and SDC acts as catalyst. A single cell with this anode demonstrates the maximum power densities of 1438, 969, and 617 mW cm ―2 at 800°C when flowing oxygen was used as oxidant and H 2 , CH 4 , and C 2 H 5 OH as fuels, respectively, and this anode displays good redox stability.

Ni/SDC Nanoparticles Modified La0.75Sr0.25Cr0.5Fe0.5O3 − δ as Anodes for Solid Oxide Fuel Cells

Fe-doped (La,Sr)CrO 3―δ (LSCrFe) oxide was modified as the anode of solid oxide fuel cells. Through vacuum-assisted impregnation processes, nanosized Sm-doped CeO 2 (SDC) and Ni particles were introduced into an anode backbone. With Ni and SDC coimpregnated LSCrFe anodes, the maximum power densities at 900°C reached 765 and 271 mW cm ―2 with H 2 and CH 4 as fuels, respectively, which were much higher than that with a nonmodified LSCrFe anode. Our results indicated that nanosized Ni particles played a primary role in performance enhancement. No carbon deposition was detected for all tested LSCrFe-based anodes.

Effect of gas supply method on the performance of the single-chamber SOFC micro-stack and the single cells

The effect of gas supply method on the performance of a single-chamber solid oxide fuel cell micro-stack and single cells was studied, and a novel gas supply method with separated gas vents in the gas tube was proposed. The traditional gas supply method was also investigated for comparison. Results showed that the single cells could obtain a uniform open-circuit voltage and power output by using the separated gas supply method. For the traditional gas supply method, the cell at the outlet position yielded inferior performance compared to that of the inlet cell. The gas flow rate showed a significant effect on the performance of the cells. Finally, the stack operated with the separated gas supply method produced a higher power output than that operated with the traditional gas supply method.

Cellular Structure Fabricated on Ni Wire by a Simple and Cost-Effective Direct-Flame Approach and Its Application in Fiber-Shaped Supercapacitors

Cellular metals with the large surface/volume ratios and excellent electrical conductivity are widely applicable and have thus been studied extensively. It is highly desirable to develop a facile and cost-effective process for fabrication of porous metallic structures, and yet more so for micro/nanoporous structures. A direct-flame strategy is developed for in situ fabrication of micron-scale cellular architecture on a Ni metal precursor. The flame provides the required heat and also serves as a fuel reformer, which provides a gas mixture of H2 , CO, and O2 for redox treatment of metallic Ni. The redox processes at elevated temperatures allow fast reconstruction of the metal, leading to a cellular structure on Ni wire. This process is simple and clean and avoids the use of sacrificial materials or templates. Furthermore, nanocrystalline MnO2 is coated on the microporous Ni wire (MPNW) to form a supercapacitor electrode. The MnO2 /MPNW electrode and the corresponding fiber-shaped supercapacitor exhibit high specific capacitance and excellent cycling stability. Moreover, this work provides a novel strategy for the fabrication of cellular metals and alloys for a variety of applications, including catalysis, energy storage and conversion, and chemical sensing.