scholarly journals Performance Optimization of μDMFC with Foamed Stainless Steel Cathode Current Collector

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6608
Author(s):  
Zhengang Zhao ◽  
Fan Zhang ◽  
Yanhui Zhang ◽  
Dacheng Zhang
Keyword(s):  
Stainless Steel ◽  
Flow Field ◽  
Power Density ◽  
Current Collector ◽  
Methanol Solution ◽  
Maximum Power Density ◽  
Type Flow ◽  
Different Types ◽  
Cathode Current ◽  
Total Impedance

The micro direct methanol fuel cell (μDMFC) has attracted more and more attention in the field of new energy due to its simple structure, easy operation, and eco-friendly byproducts. In a μDMFC’s structure, the current collector plays an essential role in collecting the conduction current, and the rational distribution of gas and water. The choice of its material and flow fields would significantly impact the μDMFC’s performance. To this end, four different types of cathode current collector were prepared in this study. The materials selected were stainless steel (SS) and foam stainless steel (FSS), with the flow fields of hole-type and grid-type. The performance of the μDMFC with different types of cathode current collector was investigated by using polarization curves, electrochemical impedance spectroscopy (EIS), and discharging. The experimental results show that the maximum power density of μDMFC of the hole-type FSS cathode current collector is 49.53 mW/cm2 at 70 °C in the methanol solution of 1 mol/L, which is 115.72% higher than that of the SS collector. The maximum power density of the μDMFC with the grid-type FSS collector is 22.60 mW/cm2, which is 27.39% higher than that of the SS collector. The total impedance of the μDMFC of the FSS collector is significantly lower than that of the μDMFC of the SS collector, and the total impedance of the μDMFC with the hole-type flow field collector is lower than that of the grid-type flow field. The discharging of μDMFC with the hole-type FSS collector reaches its optimal value at 70 °C in the methanol solution of 1 mol/L.

scholarly journals Performance optimization of an air-breathing PEM fuel cell

2019 ◽  
Vol 25 (3) ◽  
pp. 289-298
Author(s):  
Levent Akyalçın
Keyword(s):  
Fuel Cell ◽  
Power Density ◽  
Power Output ◽  
Performance Optimization ◽  
Current Collector ◽  
Maximum Power ◽  
Design Parameters ◽  
Membrane Electrode ◽  
Maximum Power Density ◽  
Cathode Current

In this study, Taguchi?s experimental design is used to determine the optimum component combination of a membrane electrode assembly and cathode current collector opening geometry to obtain maximum power density of an airbreathing polymer electrolyte membrane fuel cell at 0.5 V. An analysis of variance was conducted to figure out the optimum levels and significant differences of the effect of the combinations, followed by a performance measurement analysis. Experimental investigations of the effecting parameters enabled the determination of the optimum configuration of the MEA and cathode current collector opening geometry design parameters for maximum power density at a certain cell potential. Effective parameters which enable withdrawal of a maximum power output from an ABPEMFC at 0.5 V are, in order of effectiveness: the amount of platinum on the cathode, the thickness of the Nafion membrane, the cathode current collector opening geometry, and the amount of platinum on the anode. Optimum component combinations are: 0.45 mgPt cm?2 for the platinum loading on the cathode, Nafion 112 for membrane, a vertical cathode opening geometry and 1.78 mg cm?2 for the amount of platinum on the anode. For these component combinations, a 98.5 mW cm?2 power output was obtained from an ABPEMFC at 0.5 V cell voltage.

scholarly journals IDDES Evaluation of Oscillating Hydraulic Jumps

2018 ◽  
Vol 40 ◽  
pp. 05067 ◽  
Author(s):  
Vimaldoss Jesudhas ◽  
Frédéric Murzyn ◽  
Ram Balachandar
Keyword(s):  
Flow Field ◽  
Hydraulic Jump ◽  
Three Dimensional ◽  
Wall Jet ◽  
Hydraulic Jumps ◽  
Vortical Structures ◽  
Instantaneous Flow Field ◽  
Type Flow ◽  
Different Types ◽  
Flow Features

This paper presents the results of three-dimensional, unsteady, Improved Delayed Detached Eddy Simulations of an oscillating and a stable hydraulic jump at Froude numbers of 3.8 and 8.5, respectively. The different types of oscillations characterised in a hydraulic jump are analysed by evaluating the instantaneous flow field. The instability caused by the flapping wall-jet type flow in an oscillating jump is distinct compared to the jump-toe fluctuations caused by the spanwise vortices in the shear layer of a stable jump. These flow features are accurately captured by the simulations and are presented with pertinent discussions. The near-bed vortical structures in an oscillating jump is extracted and analysed using the λ2 criterion.

scholarly journals The effectivness of using a non-platinum material combination for the catalyst layer of a proton exchange membrane fuel cell

2016 ◽  
Author(s):  
◽  
Dwayne Jensen Reddy
Keyword(s):  
Fuel Cell ◽  
Flow Field ◽  
Power Density ◽  
Catalyst Layer ◽  
Test Cell ◽  
Maximum Power ◽  
Polymer Electrolyte Fuel Cell ◽  
Membrane Electrode ◽  
Maximum Power Density ◽  
Flow Rates

The effectiveness of using a low cost non - platinum (Pt) material for the catalyst layer of a polymer electrolyte fuel cell (PEMFC) was investigated. A test cell and station was developed. Two commercial Pt loaded membrane electrode assemblies (MEA) and one custom MEA were purchased from the Fuelcelletc store. Hydrogen and oxygen were applied to either side of the custom MEA which resulted in an additional sample tested. An aluminium flow field plate with a hole type design was manufactured for the reactants to reach the reaction sites. End plates made from perspex where used to enclose the MEA, flow field plates, and also to provide reactant inlet and outlet connection points. The developed test station consisted of hydrogen and oxygen sources, pressure regulators, mass flow controllers, heating plate, and humidification units. A number of experimental tests were carried out to determine the performance of the test cells. These tests monitored the performance of the test cell under no-load and loaded conditions. The tests were done at 25 °C and 35 °C at a pressure of 0.5 bar and varying hydrogen and oxygen volume flow rates. The no-load test showed that the MEA’s performed best at high reactant flow rates of 95 ml/min for hydrogen and 38 ml/min for oxygen. MEA 1, 2, 3, and 4 achieved an open circuit voltage (OVC) of 0.936, 0.855, 0.486 and 0.34 V respectively. The maximum current density achieved for the MEAs were 0.3816, 0.284, 15x10-6, and 50x10-6 A/cm2. Under loaded conditions the maximum power densities achieved at 25 °C for MEA’s 1, 2, 3, and 4 were 0.05, 0.038, 2.3x10-6, 1.99x10-6 W/cm2 respectively. Increasing the temperature by 10°C for MEA 1, 2, 3, 4 resulted in a 16.6, 22.1, 1.79, 10.47 % increase in the maximum power density. It was found that increasing platinum loading, flow rates, and temperature improved the fuel cell performance. It was also found that the catalytic, stability and adsorption characteristics of silver did not improve when combining it with iridium (Ir) and ruthenium oxide (RuOx) which resulted in low current generation. The low maximum power density thus achieved at a reduced cost is not feasible. Thus further investigation into improving the catalytic requirements of non Pt based catalyst material combinations is required to achieve results comparable to that of a Pt based PEMFC.

scholarly journals Effect of substrate type and concentration on the performance of a double chamber microbial fuel cell

2019 ◽  
Vol 81 (7) ◽  
pp. 1336-1344 ◽  
Author(s):  
Zia Ullah ◽  
Sheikh Zeshan
Keyword(s):  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Power Density ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Maximum Power ◽  
Maximum Power Density ◽  
Ohmic Losses ◽  
Different Types ◽  
Double Chamber

Abstract The microbial fuel cell (MFC) provides new opportunities for energy generation and wastewater treatment through conversion of organic matter into electricity by electrogenic bacteria. This study investigates the effect of different types and concentrations of substrates on the performance of a double chamber microbial fuel cell (DCMFC). Three mediator-less laboratory-scale DCMFCs were used in this study, which were equipped with graphite electrode and cation exchange membrane. The MFCs were fed with three different types of substrates (glucose, acetate and sucrose) at a chemical oxygen demand (COD) concentration of 1,000 mg/L. The selected substrate (acetate) was studied for three different concentrations of 500, 2,000 and 3,000 mg/L of COD. Results demonstrated that acetate was the best substrate among the three different substrates with maximum power density and COD removal of 91 mW/m2 and 77%, respectively. Concentration of 2,000 mg/L was the best concentration in terms of performance with maximum power density and COD removal of 114 mW/m2 and 79%, respectively. The polarization curve shows that ohmic losses were dominant in DCMFCs established for all three substrates and concentrations.

Carbon Nano Tube-Polymer Hybrid Nanocomposite Electrodes for Porous Polydimethylsiloxane Sponge-Based Flexible Triboelectric Nanogenerators

2021 ◽  
Vol 21 (9) ◽  
pp. 4680-4684
Author(s):  
Dae-Hyeon Kwon ◽  
Jaebum Jeong ◽  
Yongju Lee ◽  
Jun-Kyu Park ◽  
Suwoong Lee ◽  
...  
Keyword(s):  
Power Density ◽  
Output Voltage ◽  
Maximum Power ◽  
Maximum Power Density ◽  
Flexible Electrodes ◽  
Flexible Devices ◽  
Copper Electrodes ◽  
Polymer Hybrid ◽  
Triboelectric Nanogenerators ◽  
Carbon Nano Tube

Flexible triboelectric nanogenerators (TENGs) have attracted much attention because of its environmentally friendly, practical, and cost-producing advantages. In flexible TENGs, it is important to study the flexible electrodes in order to fabricate the fully flexible devices. Here, we compared electrical characteristics of the sponge porous polydimethylsiloxane (PDMS)-based flexible TENGs with two types of flexible electrodes, copper and carbon nanotube (CNT)-PDMS electrodes. The output voltage and maximum power density of sponge PDMS-based flexible TENGs with copper and CNTPDMS electrodes were compared. The voltage and power density of sponge PDMS-based flexible TENGs with CNT-PDMS electrodes were improved compare to those with copper electrodes. The output voltage and the maximum power density of sponge PDMS-based flexible TENGs with copper and CNT-PDMS electrodes increased 4 times and 7 times, respectively. It is attributed to higher electrical conductivity and stably flow electricity of CNT than those of copper.

Investigation of nitriding treated Ni-free stainless steel as current collector for 5 V-class Li-ion secondary cell

2019 ◽  
Vol 295 ◽  
pp. 1052-1056 ◽  
Author(s):  
Sayoko Shironita ◽  
Neil Ihsan ◽  
Kotaro Konakawa ◽  
Kenichi Souma ◽  
Minoru Umeda
Keyword(s):  
Stainless Steel ◽  
Current Collector ◽  
Li Ion

Influence of Composition of Gd-Doped Ceria Electrolyte on Performance of Solid Oxide Fuel Cell

2012 ◽  
Vol 724 ◽  
pp. 389-392 ◽  
Author(s):  
Yuta Ibusuki ◽  
Yoshihiro Hirata ◽  
Soichiro Sameshima ◽  
Naoki Matsunaga
Keyword(s):  
Power Density ◽  
Open Circuit ◽  
Solid Oxide ◽  
Maximum Power ◽  
Cell Performance ◽  
Excess Oxygen ◽  
Doped Ceria ◽  
Oxide Fuel ◽  
Maximum Power Density ◽  
Oxide Ion Conductivity

Cell performance was measured for four types of Ni (40 vol%)-Gd-doped ceria (GDC) anode-supported solid oxide fuel cells with GDC electrolyte (40-120 μm thickness) of Ce1-xGdxO2-x/2 compositions (x = 0.05, 0.1, 0.15 and 0.2) at 773-1073 K using a H2 fuel. (La0.8Sr0.2)(Co0.8Fe0.2)O3 cathode was printed on the GDC films. The open circuit voltage and maximum power density at 873-1073 K showed a maximum at x = 0.1. The maximum power density at x = 0.1 was 166 and 506 mW/cm2 at 873 and 1073 K, respectively. The excess oxygen vacancy at x = 0.1-0.2, which does not contribute to the oxide ion conductivity, reacts with a H2 fuel to form electrons (H2 + VO 2H+ + VO×, VO× VO + 2e-). This reaction reduces the cell performance.

Experimental Study on Testing Ni-Containing Stainless Steel Protective Coatings by Pulsed Laser Scratching

2010 ◽  
Vol 43 ◽  
pp. 651-656
Author(s):  
Ai Xin Feng ◽  
Yu Peng Cao ◽  
Chuan Chao Xu ◽  
Huai Yang Sun ◽  
Gui Fen Ni ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Power Density ◽  
Laser Power ◽  
Protective Coatings ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Laser Power Density ◽  
The Matrix ◽  
The Impact

In the experiment, we use pulsed laser to conduct discrete scratching on Ni-containing stainless steel protective coatings to test residual stress situation after the matrix is scratched; then to analyze the the impact of the impact stress wave on coating - substrate bonding strength according to the test results, finally to infer the laser power density range within which it occurs coating failure. The study shows that: after laser discrete scratching, the residual stress of the center of the laser-loaded point on matrix surface gradually reduces when the pulsed laser power density increases. The matrix produces a corresponding residual compressive stress under the laser power density reaches a certain value. The actual failure threshold values are 12.006 GW/cm2, 11.829GW/cm2 and 12.193GW/cm2 measured by the three-dimensional topography instrument testing the discrete scratch point of three groups of samples and verified by using a microscope

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