Characteristics Of Fuel Cell Research Articles

Influence of Ionomer Adhesion Ratio of Catalyst Layer on Electrode Characteristics of Polymer Electrolyte Fuel Cell

Influence of Ionomer Adhesion Ratio of Catalyst Layer on Electrode Characteristics of Polymer Electrolyte Fuel Cell

Study on the Electricity Generation Characteristics of Microbial Fuel Cell with Different Substrates

We use anhydrous sodium acetate, glucose, lactose and Colocasia antiquorum Schott as anode substrate to study the periodic curve of battery voltage and stable output voltage of different substrates, The results showed that the four kinds of microbial fuel cells with sodium acetate, glucose, lactose and pretreated Colocasia antiquorum Schott as anode substrate had the following power generation periods: 23.98 d, 20.15 d, 18.84 d and 23.52 d, respectively, and the stable voltage at the two ends of the resistance of microbial fuel cells with four different anode substrates are 0.77 V, 0.75 V, 0.65 V and 0.70 V respectively. We found at the same carbon source concentration, MFC with sodium acetate as the substrate has the best electricity production characteristics. When the pretreated Colocasia antiquorum Schott is used as anode substrate, the time for cell voltage to rise from initial value to stable value is the shortest, and as a carbon source, it can also play a dominant role in the process of electric energy collection and utilization.

Various Flow-Field Designs for Enhancing Fuel the Cell Performance of Proton Exchange Membrane Fuel Cells

The flow-field design is an essential key in the operation of fuel cells, it conducts main functions such as contributing reactants to the membrane electrolyte assembly (MEA) over gas diffusion layers, conductive part, clamping MEA as well as water management & thermal management and so on. As a result, it is necessary to optimize the flow-field design of fuel cells in order to enhance fuel cell operation characteristics. This paper shows numerical analyses of fuel cell characteristics based on 4 configurations of flow-field in order to find out the best design for enhancing fuel cell performance. The results showed that the different design of flow-field for the anode side and the cathode side can contribute to enhancing fuel cell operation characteristics due to their difference in water formation and discharge. Indeed, the fuel cell configuration with the serpentine flow field in anode side and the pin flow field in the cathode side is the best design because it leads to reducing the water flooding in the cathode side and drying in the anode side. The maximum power density of configuration 1-4 is 0.515, 0.528, 0.585, respectively. It means an improvement of 13.6% percentage can be observed. The research results of this research are the foundation of optimizing the design of the flow-field design.

Characteristics of Ascorbic Acid Fuel Cells Using SWCNT and PEDOT*PSS Composite Anodes

Direct ascorbic acid (AsA) fuel cells based on SWCNT and PEDOT*PSS composite anodes were studied. The open circuit voltage was 0.55 V against Pt-black air cathode. The maximum power density (4.9 mWcm−2) using SWCNT alone was enhanced to 11.3 mWcm−2 by coating SWCNT with PEDOT*PSS. Cell performances among various anode materials of SWCNT, carbon powder, Pt-black and composites with PEDOT*PSS are discussed in terms of specific surface areas and roles of conducting polymers.

Analysis of Characteristics of Pem Fuel Cell

In present scenario non conventional energy sources plays an important role in various applications. This paper focuses on study of Proton Exchange Membrane (PEM) fuel cell and verification of its polarization characteristics by using “Matlab Simulation”.

Development of co-sintering process for anode-supported solid oxide fuel cells with gadolinia-doped ceria/lanthanum silicate bi-layer electrolyte

Gadolinia-doped ceria (GDC) and lanthanum silicate (LS) are expected to be promising materials for electrolytes of solid oxide fuel cells (SOFCs) because of their high ionic conductivities at intermediate temperatures. However, performance degradation of SOFCs is caused by current leakage through GDC and poor densification of LS. In the present study, LS was used as a blocking layer for preventing the current leakage of GDC electrolyte. Thermal shrinkage measurements and scanning electron microscopy (SEM) observation suggested that the addition of Bi2O3 in LS electrolyte (LSB) contributed to the decrease in the sintering temperature of the LS and improved densification of the GDC/LS bi-layer electrolyte. Consequently, the open-circuit voltage for the cell with GDC/LS and GDC/LSB bi-layer electrolytes increased effectively in comparison with that of the cell with GDC single-layer electrolyte. The electrical conductivity and fuel cell characteristics were compared among the cells with GDC, GDC/LS, and GDC/LSB electrolytes.

Electrochemical Characteristics of Solid Oxide Fuel Cell Using Gas from Biomass Gasification

Gasification of biomass using autothermal downdraft gasifier and the characteristics of gasification were analyzed. The prepared gasified gas was supplied to the electrolyte-supported solid oxide fuel cells (SOFCs) and their electrochemical characteristics were analyzed. In the gasifier, the biomass was converted to the mixed gas containing H2 and CO at the efficiency of ca. 85 % and its composition was mainly affected by the water gas shift (WGS) reaction in the reduction area. The exchange current densities of anode electrode in hydrogen and model gasified gas were evaluated. In anode electrode by gasified gases, oxidation of H2 rather than CO mainly occurred due to WGS reaction. The maximum power density attained by gasified gas was 68 % of that by H2.

Power Generation Characteristics of Solid Oxide Fuel Cell Fueled by Nitrogenous Compound

We have started working on aqueous-urea-fueled SOFC APU systems for diesel powered vehicles. In the system, aqueous urea solution is thermally hydrolyzed to NH3 and CO2, and NH3 is then supplied to SOFC systems as fuel. Moreover, remaining NH3 in the off-gas from SOFC system can be reused as a denitrifying agent for SCR (Selective Catalytic Reduction) together with aqueous-urea. In this study, SOFC system directly fueled by NH3 was tested and it was confirmed that its polarization test was equivalent to H2 and N2 mixture fuel under fuel utilization of 70% to 75%. And it was also confirmed that NH3 in off-gas was thermally decomposed to almost the same level as the theoretical one at OCV.We will conduct directly fueled NH3 SOFC long-term operation tests and aqueous-urea-fueled SOFC demonstration tests in the near future. Then, we will proceed with the feasibility study of the total system.

The Characteristics of Cermet-Supported Tubular Solid Oxide Fuel Cells Manufactured by Thermal Spraying

Tubular solid oxide fuel cells (SOFCs) with cells in series assembled on a porous cermet-support tube with self-sealing were designed for easy manufacturing by thermal spraying. Such design has distinct features of high power output, good thermal matching of support tube with different functional layers, and low ohmic loss from two electrode leaders. Tubular SOFCs with different numbers of cells (6, 10, and 20) in series were manufactured on the flame-sprayed NiCr-Al2O3 support tube with an insulating interlayer, YSZ electrolyte, Ni-YSZ anode, and La0.8Sr0.2MnO3-based cathode. All components in the tubular SOFC were produced by thermal spray processes. The performance test showed that tubular SOFC presented an open circuit voltage and maximum output power being proportional to numbers of cells in series. For tubular SOFC with 10 cells with a total length of 200 mm, the test yielded a peak power output over 20 W at 800 °C with a maximum power density over 200 mW/cm2. Moreover, it was also found that the tubular SOFC with 20 cells presented a comparable peak powder density. Therefore, it is clearly demonstrated that the cermet-supported tubular design is suitable for thermal spraying manufacturing with a high output performance.

Electrochemical Characteristics of Fuel Cells with CaZr0.9Y0.1O3 – δ Electrolyte Film Supported by Nickel–Cermet Anode

Electrochemical characteristics of fuel cells containing CaZr0.9Y0.1O3 – δ film supported by Ni–CaZr0.95Sc0.05O3 – δ anode are studied. It is shown that the diffusion of nickel from the electrode-support favors the increase in electronic conductivity of the electrolyte. It is found that to provide sufficiently high transport numbers of ions, the thickness of the CZY electrolyte film should not be smaller than 4 µm. The polarization losses on the anode are concluded to be the main reason for the lower power of fuel cells with thin-film electrolyte.

Direct Sodium Hypophosphite Fuel Cell System

The goal of the presented project is development a new type of direct sodium hypophosphite fuel cell (DSHFC) System, with Sodium Hypophosphite direct oxidation at the CoB2O4 based anode. Synthesized CoB2O4 was used as a catalyst of sodium hypophosphate oxidation [1,2]. CoB2O4 was annealed at 280˚C - 350˚C demonstrated best catalytic activity. In X-ray phase analysis of the sample show the X-ray diffraction pattern according to the ASTM standard of СoB2O4 (2.88,2.44, 2.03, 1.86 Å). Sodium Hypophosphite is oxidized in alkaline media. Hypophosphite-ion is adsorbed at metal oxide CoB2O4 surface, hydrogen atom, which is connected with catalyst surface by covalent bond, attenuates P-H bond and finally cleaves it; hydrogen is replaced by hydroxide-ion of water (1, 2) which causes hypophosphite transformation in phosphate. The overall anodic reaction will be (3) H2O=H++OH- (1) H2PO2 -ads + OH-ads = H2PO3 -ads+ H++ 2e- (2) NaH2PO2 + H2O = NaH2PO3 + 2H+ +2e- (3) The DSHFC anode was made by next steps: the CoB2O4 powder and carbon black XC72 powder 1:3 were mixed in isopropanol alcohol, as a binder was used polytetrafluoroethylene suspension and sonicated during 30 min. A carbon felt was used as an anode substrate and catalytic layer was covered bay spry-gun and heated at 250 oC during 5 min. the figure 1 show the DSHFC construction. The fuel Cell is undivided. As a cathode was used ordinary gas diffusion electrode for O2 reduction. The Anode and the cathode geometric surface area was 4 cm2 (2cm X 2cm) The Voltage –Ampere characteristics of the Direct Sodium Hypophosphite Fuel Cell was recorded with various concentrations of electrolyte X NaH2PO2 + Y NaOH, electrolyte was feed in to fuel cell by pump, oxygen to the cathode chamber was feed by air compressor (pressure 35-40 mm.H2O).Test were performed at room temperature. External load was changed from 10 000 Ω to 0.1 Ω. Current and voltage of DSHFC was recorded by multi-meters. In optimal conditions, electrolyte 1M NaH2PO2 + 2 NaOH, external load 1 Ω, the current density was 36 mA cm-1, the suitable power density was 13,5 mwt cm-1, open circuit potential was 1v References [1] Electroless plating: fundamentals and applications edited by G. O. Mallory, J. B. Hajdu [2] P.O. Nikoleishvili, at all, Russian Journal of Electrochemistry, 2015, Vol. 51, No. 7, pp. 665–671 Figure 1

Application of flower pollination algorithm for enhanced proton exchange membrane fuel cell modelling

Modelling of Proton Exchange Membrane Fuel Cell (PEMFC) characteristics assumes importance in view of better understanding, analysis and design of high efficient fuel cell systems. Limited by its complexity, strongly coupled behaviour and multivariate characteristics; optimization techniques are attempted to model PEMFC characteristics. Influenced by convergence speed, computational efficiency, level of complexity, dependency on initial solution and ability to locate global optimum; recently evolved Flower Pollination Algorithm is utilized in this work for PEMFC modelling. This method is applied to derive unknown model parameters of fuel cells having different characteristics and rating. Further, to illustrate the superiority of the method, results obtained are compared with some of the recent works. Moreover, to showcase its efficiency; comprehensive comparison is made in terms of model parameter values, sum of squared error, individual absolute error and relative error values.

Theoretical modeling of the gas humidification effect on the characteristics of proton ceramic fuel cells

Proton ceramic fuel cells are promising electrochemical converters that produce electrical energy by oxidizing hydrogen. Understanding the impact of gas humidification on the characteristics of such fuel cells is pivotal for the development of high-performance devices. This study develops a theory elucidating the effect of hydrogen and air humidity on the output characteristics of fuel cells based on proton-conducting oxide membrane with mixed (proton and hole) conductivity. The theory is based on a self-consistent description of the strong non-uniform distribution of charge carriers inside the membrane and the variation of the gas phase composition along the fuel and air channels. It is shown that the total current density significantly and nonmonotonously depends on humidity of the inlet hydrogen fuel, while humidification of the inlet air has minor effect on the fuel cell characteristics. The influence of the anode and cathode gas humidity on the distribution of the various fuel cell parameters (current densities, resistivity, etc.) along the membrane is also determined. The obtained results reveal the possibility of enhancing the performance of the proton ceramic fuel cells with low polarization losses by optimizing the composition of the inlet hydrogen fuel.

Study on the Uncoupling Characteristics of PEM Fuel Cell by Segmented Cell Technology

Study on the Uncoupling Characteristics of PEM Fuel Cell by Segmented Cell Technology

Pore-Forming Agents for the Supporting Ni-Based SOFC Anode

The effect of the type (semolina, starch, and ashless filter paper) and amount (5 and 10 wt %) of pore-forming agents on the structure of supporting Ni-cermet anodes and characteristics of solid-oxide fuel cells on their basis has been studied. It has been found that the use of paper fibers as the pore-forming agent doubles the open porosity of the anode as compared with equal amounts of semolina or starch. It has been shown that the long cylindrical pores formed by fibers allow fast transport of gases through the anode bulk, which has a positive effect on the fuel cell characteristics.

Visualization technique for time-variant hydrogen concentration distribution in porous materials using hydrogen storage alloy thin film

An understanding of the mechanism whereby hydrogen is transported in porous materials is a key factor when developing hydrogen-utilizing equipment. For instance, studying the start-up and degradation characteristics of Polymer Electrolyte Fuel Cell (PEFC) requires the distribution of the time-variant hydrogen concentration to be measured at times of the order of 10−1 s. However, few studies on time-variant hydrogen transport in porous materials have been reported, and conventional measuring methods are insufficient in terms of their time resolution. This study led to the development of a visualization technique using the characteristics of a MgNi thin film, the reflection rate of which changes along with the hydrogen concentration. The new visualization technique makes it possible to investigate and understand the distribution of the time-variant hydrogen concentration.

Fundamental Characteristics of High Functional Direct Carbon Fuel Cell Composed of Tubular Molten Carbonate Fuel Cell

In order to the solve global warming and the increase of food wastes, we have already proposed the High Functional Direct Carbon Fuel Cell (HF-DCFC) composed of molten salts gasification system and molten carbonate fuel cell (MCFC) since 2011. This gasification system generates CO and H2 by supplying organic wastes into molten salts. The MCFC formed to tubular (T-MCFC) is used as gas pipeline for the gasification system. This paper aimed at the evaluation of the fundamental characteristics of the T-MCFC, and the establishment of the manufacturing method of the T-MCFC stack composed of 2cells. As a result, the T-MCFC was able to obtain a good performance though it was necessary to optimize the electrolyte loading ratio. The basic manufacturing method of the T-MCFC stack was able to be also established.

固体高分子形燃料電池を導入した住宅におけるエネルギー需要と機器稼動特性に関する研究 第3報 燃料電池・ガスエンジン・太陽エネルギー利用システムの総合評価

固体高分子形燃料電池を導入した住宅におけるエネルギー需要と機器稼動特性に関する研究 第3報 燃料電池・ガスエンジン・太陽エネルギー利用システムの総合評価

Performance Characteristics of Solid Oxide Fuel Cells with YSZ/CGO Electrolyte

This paper presents the results of performance evaluation of anode-supported solid oxide fuel cells (SOFC) with magnetron sputtered YSZ/CGO bilayer electrolyte, and composite LSCF-CGO cathode. Deposition of the YSZ/CGO electrolyte with the thickness of up to 14 microns was performed on the commercial anode substrates with dimensions of 5×5 cm2. The LSCF-CGO cathode of the fuel cells was formed by the screen-printing method. The microstructure of the YSZ/CGO bilayer electrolyte and LSCF-CGO cathode was studied by scanning electron microscopy. Comparison of the fuel cells performance with different thicknesses of the YSZ and CGO layers was carried out by measuring current-voltage and power characteristics, and also by testing the long-term stability of cell power at the temperature of 750 °C and voltage of 0.7 V.

High Performance Anode for Direct Cellulosic Biomass Fuel Cells Operating at Intermediate Temperatures

Abstract Cellulosic biomass resources have considerable potential as a renewable energy source that can be used for the cogeneration of electricity and heat. The utilization of these resources generally requires three major systematic processes: gasification, gas processing, and gas utilization. If a power generator could operate using wood resources directly as fuels, then this system could be significantly simplified, thereby reducing initial equipment cost and enhancing application flexibility. An intermediate-temperature fuel cell could possibly realize such an operation; however, the fuel-cell characteristics, especially the catalytic activity of the Pt/C anode, are not sufficient at present. In this study, we attempted to improve the anode activity by alloying Pt with other metals, followed by optimization of the alloy in terms of its atomic ratio and content. The resulting PtFe/C anode yielded higher power densities (37–42 mW cm−2) and energy densities (125–169 Wh kg−1) at 250 °C for fuels composed of cypress, tissue paper, and cotton, compared to those obtained using the Pt/C anode, despite its smaller Pt loading.