Investigation of a Passive DMFC Mini-Stack at Room Temperature

2010 ◽  
Vol 72 ◽  
pp. 271-276 ◽  
Author(s):  
Antonino Salvatore Arico’ ◽  
Vincenzo Baglio ◽  
Alessandro Stassi ◽  
Vincenzo Antonucci
Keyword(s):  
Direct Methanol Fuel Cells ◽  
Operation Mode ◽  
High Energy ◽  
High Energy Density ◽  
Catalyst Loading ◽  
Ambient Conditions ◽  
Electrode Thickness ◽  
Power Sources ◽  
Catalytic Sites ◽  
Direct Methanol

Direct Methanol Fuel Cells (DMFCs) are promising candidates for portable electric power sources because of their high energy density, lightweight, compactness, simplicity as well as easy and fast recharging. Recently, the attention has been focused on portable applications with passive-feed DMFCs. Under this configuration, DMFCs operate without any external device for feeding methanol and blowing air into the cells. An investigation of properties and operating parameters of a passive DMFC monopolar mini-stack, such as catalyst loading and methanol concentration, was carried out. From this analysis, it was derived that a proper Pt loading is necessary to achieve the best compromise between electrode thickness and number of catalytic sites for the anode and cathode reactions to occurs at suitable rates. Methanol concentrations ranging from 1 M up to 10 M (40 vol%) and an air-breathing operation mode were investigated. A maximum power of 225 mW was obtained at ambient conditions for a three-cell stack, with an active single cell area of 4 cm2 corresponding to a power density of about 20 mW cm-2.

Evaluation of the Performance Characteristics of a Direct Methanol Fuel Cell With Multifuels

2010 ◽  
Vol 7 (4) ◽  
Author(s):  
Sujith Mohan ◽  
S. O. Bade Shrestha
Keyword(s):  
Fuel Cell ◽  
Direct Methanol Fuel Cell ◽  
Direct Methanol Fuel Cells ◽  
Operating Temperature ◽  
High Energy ◽  
High Energy Density ◽  
Power Sources ◽  
Transport Losses ◽  
Direct Methanol ◽  
Methanol Fuel Cell

Direct methanol fuel cells are one of the alternate power sources for the field of power electronics because of their high energy density. The benefits of a fuel cell toward the environment can be greatly improved if the fuel used for its application comes from renewable sources. In this study, the performance of a direct methanol fuel cell was investigated under five different methanol concentrations. The effect of methanol concentration on the cell operating temperature is studied. Impedance spectroscopy was conducted to measure the ohmic, activation, and mass transport losses for all concentrations. The cell performance was evaluated using methane and ethanol fuels and this was compared with methanol operation.

Evaluation of the Performance Characteristics of a Direct Methanol Fuel Cell With Multi Fuels

2009 ◽  
Author(s):  
Sujith Mohan ◽  
S. O. Bade Shrestha
Keyword(s):  
Fuel Cell ◽  
Direct Methanol Fuel Cell ◽  
Direct Methanol Fuel Cells ◽  
Operating Temperature ◽  
High Energy ◽  
High Energy Density ◽  
Power Sources ◽  
Transport Losses ◽  
Direct Methanol ◽  
Methanol Fuel Cell

Direct methanol fuel cells are one of the alternate power sources for the field of power electronics because of their high energy density. The benefits of a fuel cell towards the environment can be greatly improved if the fuel used for its application comes from renewable sources. In this study, the performance of a direct methanol fuel cell was investigated under five different methanol concentrations. The effect of methanol concentration on the cell operating temperature is studied. Impedance spectroscopy was conducted to measure the ohmic, activation and mass transport losses for all concentrations. The cell performance was evaluated using methane and ethanol fuels and this was compared with methanol operation.

Anodic engineering towards high-performance direct methanol fuel cells with non-precious-metal cathode catalysts

2020 ◽  
Vol 8 (3) ◽  
pp. 1113-1119 ◽  
Author(s):  
Zhangxun Xia ◽  
Xinlong Xu ◽  
Xiaoming Zhang ◽  
Huanqiao Li ◽  
Suli Wang ◽  
...  
Keyword(s):  
Fuel Cells ◽  
High Performance ◽  
Direct Methanol Fuel Cells ◽  
High Energy ◽  
High Energy Density ◽  
Environmental Friendliness ◽  
Cathode Catalysts ◽  
The Past ◽  
Direct Methanol ◽  
Methanol Fuel Cells

Direct methanol fuel cells (DMFCs) have drawn extensive interest for the past two decades both in scientific research and industrial engineering circles for their advantages of high energy density, environmental friendliness, and easy fuel handling.

Performance Modeling of a DMFC Fueled With Methanol and Ethanol

2014 ◽  
Author(s):  
Sujith Mohan ◽  
S. O. Bade Shrestha
Keyword(s):  
Performance Modeling ◽  
Direct Methanol Fuel Cells ◽  
High Energy ◽  
Power Source ◽  
High Energy Density ◽  
Portable Devices ◽  
Transport Losses ◽  
Direct Methanol ◽  
Improved Performance ◽  
Experimental Values

Direct methanol fuel cells (DMFC) are becoming a choice of a power source in the field of power electronics, and portable devices because of their high energy density. The benefits of using a fuel cell towards the environment will be enhanced if the fuel used for its application comes from renewable sources such as ethanol. A method of modeling of the performance of DMFC was developed and validated with the experimental data obtained from a passive DMFC operated under varying methanol and ethanol concentrations. Impedance spectroscopy was employed to measure ohmic, activation and mass transport losses for all concentrations. Improved performance of the cell was observed when the concentrations of the solutions were closer to stoichiometric values. The model predicted results were compared to the corresponding experimental values and found satisfactory.

The Role of Fuel Cells for Consumer Electronic Products and Toys

2003 ◽  
Author(s):  
B. Banazwski ◽  
R. K. Shah
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Direct Methanol Fuel Cells ◽  
High Energy ◽  
Consumer Products ◽  
Proton Exchange ◽  
Consumer Electronics ◽  
High Energy Density ◽  
Direct Methanol

Batteries have not kept pace with the advancing technology that they power, but they are used in everything from cell phones, laptop computers, and toys to consumer electronics. Compared to the devices that they power, batteries are relatively heavy, expensive per unit power they produce, last a relatively short time and recharging them takes hours. The solution to this less than desired means of a power source is fuel cells. Three fuel cells, also referred to as air breathers, considered are proton exchange membrane fuel cell (PEMFC), direct methanol fuel cells (DMFC), and direct formic acid fuel cells (DFAFC). We will discuss these fuel cells for micro and portable applications within the power range of 0.5 to 20 W for potential replacement of batteries. The reason for developing such fuel cells is to harness the power stored in the high energy density fuels, which provides more power and longer run times for the same packaging volume as batteries. The advantages of each type of fuel cell over batteries, their unique characteristics, technical drawbacks, current and future consumer products, and commercial issues will be outlined in this paper. A growing mobile society and consumer demands will drive the development of fuel cell technology forward as batteries reach their limit.

scholarly journals Enhanced Cell Performance and Improved Catalyst Utilization for a Direct Methanol Fuel Cell with an In-Plane Gradient Loading Catalyst Electrode

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1787
Author(s):  
Zhixin Chang ◽  
Jiajia Zhang ◽  
Weiqi Zhang ◽  
Huaneng Su ◽  
Lei Xing ◽  
...  
Keyword(s):  
Service Life ◽  
Current Density ◽  
Direct Methanol Fuel Cells ◽  
High Energy ◽  
Power Supplies ◽  
High Energy Density ◽  
Commercial Application ◽  
Direct Methanol ◽  
Catalyst Utilization ◽  
Catalyst Electrode

Direct methanol fuel cells (DMFCs) offer high energy density, simple liquid fuel storage, and the ability to operate at ambient temperature. They may be used in a variety of portable mobile power supplies, small civilian power supplies, and automotive power supplies. However, in the process of electrochemical reaction inside a DMFC, because the reactants and products are distributed unevenly, the in-plane concentration of reactants and reaction rate are different; thus, the current density generated in the active area shows a high degree of non-uniformity. The high local current density can easily lead to the acceleration of DMFC aging. As a result, the operating cost of the DMFC is increased and the service life is shortened, which limits the commercial application of DMFCs. In this work, we develop an in-plane gradient loading catalyst. The loading on both the anode and cathode catalysts was lower near the inlet and higher close to the outlet. The experimental results of the single-cell test show that the performance of the gradient loading catalyst electrode was enhanced by up to 19.8% compared with the uniform loading catalyst at 60 °C for the same catalyst loading, especially under high current densities. In addition, the catalyst utilization was improved for the gradient loading catalyst electrode. Hence, the proposed approach shows potential for reducing the cost and increasing the service life of DMFCs.

Performance Modeling of a Direct Methanol Fuel Cell Fueled With Methanol and Ethanol

2014 ◽  
Vol 11 (6) ◽  
Author(s):  
S. O. Bade Shrestha ◽  
Sujith Mohan
Keyword(s):  
Fuel Cell ◽  
Direct Methanol Fuel Cells ◽  
High Energy ◽  
High Energy Density ◽  
Portable Devices ◽  
Transport Losses ◽  
Direct Methanol ◽  
Improved Performance ◽  
Experimental Values ◽  
Methanol Fuel Cell

Direct methanol fuel cells (DMFCs) are becoming a choice of a power source in the field of power electronics, and portable devices because of their high energy density. The benefits of using a fuel cell toward the environment will be enhanced if the fuel used for its application comes from renewable sources such as ethanol. A method of modeling of the performance of DMFC was developed and validated with the experimental data obtained from a passive DMFC operated under varying methanol and ethanol concentrations. Impedance spectroscopy was employed to measure ohmic, activation and mass transport losses for all concentrations. Improved performance of the cell was observed when the concentrations of the solutions were closer to stoichiometric values. The model predicted results were compared to the corresponding experimental values and found satisfactory.

High-pressure new phase of AgN3

2021 ◽  
pp. 2150386
Author(s):  
Shifeng Niu ◽  
Ran Liu ◽  
Xuhan Shi ◽  
Zhen Yao ◽  
Bingbing Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
Energy Density ◽  
Density Functional ◽  
High Energy ◽  
High Energy Density ◽  
Detonation Properties ◽  
Ambient Conditions ◽  
Structure Search ◽  
Enthalpy Difference ◽  
High Energy Density Material

The structural evolutionary behaviors of AgN3 have been studied by using the particle swarm optimization structure search method combined with the density functional theory. One stable high-pressure metal polymeric phase with the [Formula: see text] space group is suggested. The enthalpy difference analysis indicates that the Ibam-AgN3 phase will transfer to the I4/mcm-AgN3 phase at 4.7 GPa and then to the [Formula: see text]-AgN3 phase at 24 GPa. The [Formula: see text]-AgN3 structure is composed of armchair–antiarmchair N-chain, in which all the N atoms are sp2 hybridization. The inherent stability of the armchair–antiarmchair chain and the anion–cation interaction between the N-chain and Ag atom induce a high stability of the [Formula: see text]-AgN3 phase, which can be captured at ambient conditions and hold its stable structure up to 1400 K. The exhibited high energy density (1.88 KJ/g) and prominent detonation properties ([Formula: see text] Km/s; [Formula: see text] GPa) of the [Formula: see text]-AgN3 phase make it a potentially high energy density material.

Mg-based composites as effective materials for storage and generation of hydrogen for FC applications

2021 ◽  
pp. 53-80
Author(s):  
D. Korablev ◽  
◽  
A. Bezdorozhev ◽  
V. Yartys ◽  
J. Solonin ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Hydrogen Generation ◽  
High Energy ◽  
High Energy Density ◽  
Hydrolysis Reaction ◽  
Preparation Technique ◽  
Power Sources ◽  
Safety Issues ◽  
Renewable Power ◽  
Physical And Chemical

Today, hydrogen is considered as an ideal choice for storing and carrying energy produced by renewable power sources since it is renewable, eco-friendly and has a high energy density. However, due to the low hydrogen storage capacity, high cost and safety issues of the conventional storage methods, several challenges need to be resolved to effectively use hydrogen in mobile applications. Solid-state hydrogen storage in atomic form in hydrides is a promising method of storage for this purpose, particularly because a double amount of hydrogen can be produced via hydrolysis reaction of chemically active hydrides. Among the metal hydrides, magnesium hydride (MgH2) is considered to be one of the most attractive candidates. However, the hydrolysis reaction is rapidly hindered by the passivation layer formed on the surface of MgH2. In order to improve MgH2 hydrolysis efficiency various approaches have been applied. This paper reviews recent progress on the modifications of MgH2-based materials by adding different type of additives, including metals, oxides, hydroxides, halides and surfactants. The introduced additives possess different catalytic properties due to their intrinsic physical and chemical characteristics, and therefore can strongly influence the hydrolysis reaction of MgH2. The most promising results were obtained for various salt additives showing that the reaction rate depends mostly on the additive type rather than on concentration. The effect of preparation technique on the hydrolysis of MgH2 – MgCl2 composites was studied in detail. The obtained results indicate that efficient hydrolysis performance can be achieved by ball milling of the freshly synthesized MgH2 with 5 wt.% MgCl2 and 1 wt.% TiC–2TiB2 additives. The combination of the applied approaches exhibited a notable synergistic effect on the hydrogen generation.

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