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

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.

2019 ◽  
Vol 25 (3) ◽  
pp. 289-298
Author(s):  
Levent Akyalçın

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.


REAKTOR ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 52-58
Author(s):  
Marcelinus Christwardana ◽  
Linda Aliffia Yoshi ◽  
J. Joelianingsih

This study demonstrates the feasibility of producing bioelectricity utilizing yeast microbial fuel cell (MFC) technology with sugarcane bagasse juice as a substrate. Yeast Saccharomyces cerevisiae was employed as a bio-catalyst in the production of electrical energy. Sugarcane bagasse juice can be used as a substrate in MFC yeast because of its relatively high sugar content. When yeast was used as a biocatalyst, and Yeast Extract, Peptone, D-Glucose (YPD) Medium was used as a substrate in the MFC in the acclimatization process, current density increased over time to reach 171.43 mA/m2 in closed circuit voltage (CCV), maximum power density (MPD) reached 13.38 mW/m2 after 21 days of the acclimatization process. When using sugarcane bagasse juice as a substrate, MPD reached 6.44 mW/m2 with a sugar concentration of about 5230 ppm. Whereas the sensitivity, maximum current density (Jmax), and apparent Michaelis-Menten constant (𝐾𝑚𝑎𝑝𝑝) from the Michaelis-Menten plot were 0.01474 mA/(m2.ppm), 263.76 mA/m2, and 13594 ppm, respectively. These results indicate that bioelectricity can be produced from sugarcane bagasse juice by Saccharomyces cerevisiae.Keywords: biomass valorization, biofuel cell, acclimatization, maximum power density, Michaelis-Menten constant


Author(s):  
Jihoon Jeong ◽  
Seung-Wook Baek ◽  
Joongmyeon Bae

The metal-supported solid oxide fuel cell (SOFC) was studied. Hydrocarbon fueled operation was used to make SOFC system. Different operating characteristics for metal-supported SOFC are used than for conventional ones. Metal-supported SOFC was successfully fabricated by a high temperature sinter-joining method and the cathode was in-situ sintered. Synthetic gas, which is compounded as the diesel reformate gas composition and low hydrocarbons was completely removed by the diesel reformer. Metal-supported SOFC with synthetic gas was operated and evaluated and its characteristics analyzed. The performance of hydrogen operation shows 0.4 W·cm−2 of maximum power density. The maximum power density of the synthetic gas operation decreased to 0.22 W·cm−2 and to 0.11 W·cm−2 after 10 hours operation, respectively. Degradation occurred because a large steam quantity made an oxidation atmosphere at high temperature, causing the metallic part damage.


Author(s):  
Jeongwoo Han ◽  
Michael Kokkolaras ◽  
Panos Papalambros

Fuel cells are being considered increasingly as a viable alternative energy source for automobiles because of their clean and efficient power generation. Numerous technological concepts have been developed and compared in terms of safety, robust operation, fuel economy, and vehicle performance. However, several issues still exist and must be addressed to improve the viability of this emerging technology. Despite the relatively large number of models and prototypes, a model-based vehicle design capability with sufficient fidelity and efficiency is not yet available in the literature. In this article we present an analysis and design optimization model for fuel cell vehicles that can be applied to both hybrid and non-hybrid vehicles by integrating a fuel cell vehicle simulator with a physics-based fuel cell model. The integration is achieved via quasi-steady fuel cell performance maps, and provides the ability to modify the characteristics of fuel cell systems with sufficient accuracy (less than 5% error) and efficiency (98% computational time reduction on average). Thus, a vehicle can be optimized subject to constraints that include various performance metrics and design specifications so that the overall efficiency of the hybrid fuel cell vehicle can be improved by 14% without violating any constraints. The obtained optimal fuel cell system is also compared to other, not vehicle-related, fuel cell systems optimized for maximum power density or maximum efficiency. A tradeoff between power density and efficiency can be observed depending on the size of compressors. Typically, a larger compressor results in higher fuel cell power density at the cost of fuel cell efficiency because it operates in a wider current region. When optimizing the fuel cell system for maximum power density, we observe that the optimal compressor operates efficiently. When optimizing the fuel cell system to be used as a power source in a vehicle, the optimal compressor is smaller and less efficient than the one of the fuel cell system optimized for maximum power density. In spite of this compressor inefficiency, the fuel cell system is 9% more efficient on average. In addition, vehicle performance can be improved significantly because the fuel cell system is designed both for maximum power density and efficiency. For a more comprehensive understanding of the overall design tradeoffs, several constraints dealing with cost, weight, and packaging issues must be considered.


2005 ◽  
Vol 2 (4) ◽  
pp. 234-237 ◽  
Author(s):  
A. Verma ◽  
A. K. Jha ◽  
S. Basu

The performance of an alkaline fuel cell (AFC) is investigated using three different fuels, e.g., methanol, ethanol, and sodium borohydride. Pt∕C∕Ni was used as anode, whereas MnO2∕C∕Ni was used as standard (Electro-Chem-Technic, UK) cathode for all the fuels. Fresh mixture of electrolyte, potassium hydroxide (5M), and fuel (2M) was fed to AFC and withdrawn at a rate of 1ml∕min. The anode was prepared by dispersing platinum and activated carbon in Nafion® (DuPont USA) dispersion and placing it onto a carbon paper (Lydall, USA). Finally prepared anode material was pressed onto Ni mesh and sintered to produce the required anode. The maximum power density of 16.5mW∕cm2 is obtained at 28mA∕cm2 of current density for sodium borohydride at 25°C, whereas methanol produces 31.5mW∕cm2 of maximum power density at 44mA∕cm2 of current density at 60°C. The results obtained showed that the AFC could accept multifuels.


RSC Advances ◽  
2016 ◽  
Vol 6 (55) ◽  
pp. 50201-50208 ◽  
Author(s):  
Wenbin Hao ◽  
Yongli Mi

A direct carbon fuel cell with a CuO–ZnO–SDC composite anode was demonstrated. The maximum power density was 130 mW cm−2 at 700 °C. The results indicate that CuO–ZnO can be used as a nickel-free anode material for direct carbon fuel cells.


2002 ◽  
Vol 756 ◽  
Author(s):  
Vincenzo Baglio ◽  
Alessandra Di Blasi ◽  
Antonino S. Arico' ◽  
Vincenzo Antonucci ◽  
Pier Luigi Antonucci ◽  
...  

ABSTRACTComposite Nafion membranes containing various amounts of TiO2 (3%, 5% and 10%) were prepared by using a recast procedure for application in high temperature Direct Methanol Fuel Cells (DMFCs). The electrochemical behaviour was compared to that of a membrane-electrode assembly (MEA) based on a bare recast Nafion membrane. All the MEAs containing the Nafion-titania membranes were able to operate up to 145°C, whereas the assembly equipped with the bare recast Nafion membrane showed the maximum performance at 120°C. A maximum power density of 340 mW cm-2 was achieved at 145°C with the composite membrane in the presence of oxygen feed, whereas the maximum power density with air feed was about 210 mW cm-2.


2011 ◽  
Vol 64 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Yifeng Zhang ◽  
Lola Gonzalez Olias ◽  
Prawit Kongjan ◽  
Irini Angelidaki

A submersible microbial fuel cell (SMFC) was utilized to treat sewage sludge and simultaneously generate electricity. Stable power generation (145 ± 5 mW/m2, 470 Ω) was produced continuously from raw sewage sludge for 5.5 days. The maximum power density reached 190 ± 5 mW/m2. The corresponding total chemical oxygen demand (TCOD) removal efficiency was 78.1 ± 0.2% with initial TCOD of 49.7 g/L. The power generation of SMFC was depended on the sludge concentration, while dilution of the raw sludge resulted in higher power density. The maximum power density was saturated at sludge concentration of 17 g-TCOD/L, where 290 mW/m2 was achieved. When effluents from an anaerobic digester that was fed with raw sludge were used as substrate in the SMFC, a maximum power density of 318 mW/m2, and a final TCOD removal of 71.9 ± 0.2% were achieved. These results have practical implications for development of an effective system to treat sewage sludge and simultaneously recover energy.


2005 ◽  
Vol 3 (2) ◽  
pp. 131-136 ◽  
Author(s):  
G. Q. Lu ◽  
C. Y. Wang

A silicon-based micro direct methanol fuel cell (μDMFC) for portable applications has been fabricated and its electrochemical characterization carried out. A membrane-electrode assembly (MEA) was specially fabricated to mitigate methanol crossover. The cell with active area of 1.625cm2 demonstrated a maximum power density of 50mW∕cm2 at 60°C. Since the silicon wafer is too fragile to compress for sealing, and a thicker layer of gold has to be coated on the silicon wafer to reduce contact resistance, further development of micro DMFCs for high power application was carried out using stainless steel as bipolar plate in which flow channels were fabricated by photochemical etching technology. The maximum power density of the micro DMFC reaches 62.5mW∕cm2 at 40°C and 100mW∕cm2 at 60°C with atmospheric pressure. An 8-cell air-breathing DMFC stack has been developed. Mass transport phenomena such as water transport and oxygen transport were investigated. By using a water management technique, cathode flooding was avoided in our air-breathing DMFC stack. Furthermore, it was found that oxygen transport in the air-breathing cathode is still very efficient. The DMFC stack produced a maximum output power of 1.33W at 2.21V at room temperature, corresponding to a power density of 33.3mW∕cm2. A passive DMFC using pure methanol was demonstrated with steady-state output power of 20-25mW∕cm2 over more than 10h without heat management.


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