Guo-Bin Jung

Innovative flow-field combination design on direct methanol fuel cell performance

The flow-field design of Direct Methanol Fuel Cells (DMFCs) is an important subject about the DMFCs performance. Flow-fields play an important role on ability to transport fuel and drive out the products (H2 O, CO2 ). In general, most of fuel cells utilize the same structure of flow-field for both anode and cathode. The popular flow-fields used for DMFCs are parallel and grid designs. Nevertheless, the characteristics of reactants and products are entirely different in anode and cathode of DMFCs. Therefore; the influences of the flow-fields designs on the cell performance were investigated due to the same logic for catalyst used for cathode and anode differently. To get the better and more stable performance of DMFC, three flow-fields (Parallel, Grid and Serpentine) are utilized with different combination were studied in this research. As a consequence, by using parallel flow-field in anode side and serpentine flow -field in cathode, the most and highest power output was obtained.Copyright

Synthesis of Y0.2ZrXCe0.8−XO1.9 Electrolytes From the Sol-Gel Method for Intermediate Temperature URSOFC Application

A series of Y0.2 Zrx Ce0.8−x O1.9 compounds (0 ≤ x ≤ 0.6) had been prepared by the modified sol-gel method and characterized by powder X-ray diffraction, thermo-gravimetric analysis, four-probe resistivity, and Vickers’s hardness studies. The gels from co-precipitation were treated with heated 1-octanol. All of the samples showed fluoride structure after calcined at 600 °C. Sintering the powders of Y0.2 Ce0.8 O1.9 and Y0.2 Zr0.6 Ce0.2 O1.9 at 1300 °C gave the relative density of 95.8% and 99%, respectively. 99% relative density could be obtained for all samples after sintering at 1500 °C. This study showed a much more improved result than that of the previous reports. The hardness was 13.7 GPa for the Y0.2 Zr0.6 Ce0.2 O1.9 pellet, which was twice greater than that for Y0.2 Ce0.8 O1.9 (7.1 GPa). Therefore, the mechanical properties could be improved by the addition of ZrO2 to Y0.2 Zrx Ce0.8−x O1.9 . At 800 °C, the electrical conductivity of Y0.2 Ce0.8 O1.9 and Y0.2 Zr0.6 Ce0.2 O1.9 were 3.3 × 10−2 S/cm and 5.5 × 10−3 S/cm, respectively. The conductivity was decreased by the addition of ZrO2 to Y0.2 Ce0.8 O1.9 . It showed that the conductivity and hardness of Y0.2 Zr0.2 Ce0.6 O1.9 were 1.2 × 10−2 S/cm and 9.6 GPa, respectively, at 800 °C and could be a better electrolyte candidate for “intermediate-temperature” unitized regenerative solid oxide fuel cells.

Investigation of Different Carbon Materials with Different Coating Methods as Micro Porous Layer for Proton Exchange Membrane Fuel Cells

Abstract: In this work, two types of carbon - Vulcan XC-72R, and vapor-grown carbon fiber (VGCF, 7I¼m in length and 100 nm in diameter) were investigated as materials composing a micro porous layer (MPL). These carbon materials were either sprayed or doctor bladed on commercial carbon paper (GDS 340, CeTech Co., Ltd., Taiwan) to form an MPL with various carbon loadings and various polytetrafluoroethene (PTFE) contain ratio. All of the home-made GDLs were assembly with commercial catalyst coated membranes (CCMs, General Optics Corp., Taiwan) for fuel cell performance test. All of the membrane electrode assembly (MEA) samples were investigated by the polarization curve and Electrochemical Impedance Spectroscopy (EIS).

Development of reversible solid oxide fuel cell for power generation and hydrogen production

A reversible solid oxide fuel cell (RSOFC) provides the dual function of performing energy storage and power generation, all in one unit. When functioning as an energy storage device, the RSOFC acts like an electrolyzer in water electrolysis mode; whereby the electric energy is stored as (electrolyzed) hydrogen and oxygen gases. While hydrogen is useful as a transportation fuel and in other industrial applications, the RSOFC also acts as a fuel cell in power generation mode to produce electricity when needed. The RSOFC would be a competitive technology in the upcoming hydrogen economy on the basis of its low cost, simple structure, and high efficiency. This paper reports on the design and manufacturing of its membrane electrode assembly using commercially available materials. Also reported are the resulting performance, both in electrolysis and fuel cell modes, as a function of its operating parameters such as temperature and current density. We found that the RSOFC performance improved with increasing temperature and its fuel cell mode had a better performance than its electrolysis mode due to a limited humidity inlet causing concentration polarization.

Design and Performance Analysis of Innovative Bipolar Direct Methanol Fuel Cell Stacks with 2D Planar Configuration

In this study, an innovative planar stack design employing graphite plate with bipolar structure on the same side to replace current stainless steel is investigated. The design, fabrication, and performance evaluation of a 25 cm 2 , air-breathing, room-temperature, direct methanol fuel cell are described. The cell is completely passive with external pumps for controlling the methanol flow rate. This planar design consists of an open cathode side which allows a completely passive, self-breathing operation of the stack. Single cells with active area of 25 cm 2 showed a maximum power density of 25-40 mW. A three-cell stack was constructed in an innovative planar configuration and it produced a power output of 110 mW at 3 M of methanol concentration at room temperature. In addition, the performance gives rise to 280 mW at 3 M under air-forced mode. The more concentrated methanol solution attains higher power due to instant take away of the methanol crossover through the membrane while the oxygen within the air is ready to react with the proton from the membrane with an appropriate rate and current output.

Innovative Flow Field Combination Design on Direct Methanol Fuel Cell Performance

The flow-field design of Direct Methanol Fuel Cells (DMFCs) is an important subject about the DMFCs performance. Flow-fields play an important role on ability to transport fuel and drive out the products (H2 O, CO2 ). In general, most of fuel cells utilize the same structure of flow-field for both anode and cathode. The popular flow-fields used for DMFCs are parallel and grid designs. Nevertheless, the characteristics of reactants and products are entirely different in anode and cathode of DMFCs. Therefore; the influences of the flow-fields designs on the cell performance were investigated due to the same logic for catalyst used for cathode and anode differently. To get the better and more stable performance of DMFC, three flow-fields (Parallel, Grid and Serpentine) are utilized with different combination were studied in this research. As a consequence, by using parallel flow-field in anode side and serpentine flow -field in cathode, the most and highest power output was obtained.Copyright

Fuel Cell Research and Development in Taiwan

Fuel cells provide a clean and efficient alternative fuel technology for transportation, residential and portable power applications. From political, social, economic, energy, environmental and technological considerations, the emerging fuel cell technology is undoubtedly well worthy of long-term investment in Taiwan. In view of the success and manufacture capability of electronics and IT industries, Taiwan may play an active role in fuel cell manufacturing and is thus conducive for international strategic alliance, both in R&D and manufacturing activities. This article provides an overview of Taiwan’s technological activities and accomplishments in fuel cells, and makes recommendations for the country’s future development and commercialization of fuel cell applications.Copyright