Special Issue "Fuel Cells"

Guest Editor
Prof. Dr.-Ing. Kai Sundmacher
Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstrasse 1, D-39106 Magdeburg and Otto-von-Guericke-University Magdeburg, Universitätsplatz 2, D-39106 Magdeburg, Germany
Website: http://www.mpi-magdeburg.mpg.de/research/groups/pcp/
E-Mail:
Interests: chemical reaction engineering; separation processes; electrochemical process engineering and fuel cells; precipitation and emulsion processes; modeling and simulation

Summary:

Fuel cells allow the direct conversion of chemically stored energy into electrical energy by means of electrochemical oxidation of gaseous, liquid or solid chemical substances. Depending on the type of electrolyte being used, we distinguish between Alkaline Fuel Cells (AFC), Phoshoric Acid Fuel Cells (PAFC), Proton Exchange Membrane Fuel Cells (PEMFC), Molten Carbonate Fuel Cells (MCFC) and Solid Oxide Fuel Cells (SOFC). The preferred fuel for fuel cells is hydrogen. But since this is not a natural resource, hydrogen has to be produced either externally or internally, i.e. outside or inside the fuel cells. The latter case leads to the very attractive concept of direct fuel cells, which are able to convert hydrocarbons into hydrogen, e.g. via internal reforming. The special issue covers current trends and future developments of fuel cell technology, including both chemical as well as electrical engineering aspects.

Submission

All papers should be submitted to energies@mdpi.org with copy to the guest editor. To be published continuously until the deadline and papers will be listed together at the special websites.

Submitted papers should not have been previously published nor be currently under consideration for publication elsewhere. All papers are refereed through a peer review process. A guide for authors, sample copies and other relevant information for submitting papers are available on the Instructions for Authors page. Energies is an international peer-reviewed quarterly journal published by Molecular Diversity Preservation International.

Please visit the Instructions for Authors page before submitting a paper. Open Access publication fees are 300 CHF per paper. English correction fees (250 CHF) will be added in certain cases (550 CHF per paper for those papers that require extensive additional formatting and/or English corrections).

Article Processing Charges (APC)

Article Processing Charges (APC) will be waived for well prepared manuscripts of invited papers. For the first two volumes of this new journal the APC are of 300 CHF (or 550 CHF per paper for those papers that require extensive additional formatting and/or English corrections).

• AFC
• PAFC
• PEMFC
• MCFC
• SOFC
• hydrogen
• electrochemical energy conversion

Title: Synthesis and Characterization of Metals in Washcoat Catalysts for Autothermal Reforming of Methanol in a Microreactor-A Review
Authors: Kuen-Song Lin and Sujan Chowdhury
Department of Chemical Engineering and Materials Science/Fuel Cell Center, Yuan Ze University, Chung-Li City, 32061, R..O.C., Taiwan; E-Mail: kslin@saturn.yzu.edu.tw
Abstract: Microreactor is a new class of device and in which electrochemical oxidation reaction of higher energy content fuels and chemicals, such as alcohols has taken by the presence of washcoat nanocatalysts. This review paper has been concerned the development of nanocatalysts for production of pure hydrogen from methanol using partial oxidation, steam reforming or a combination thereof in the micro-channel reactors. The work is contributed to understand the morphology, fine structure or catalytic performance of washcoat nanocatalysts using XRD, FE-SEM/EDS, TEM, XPS or PTR. As well, physiochemical properties are considered for the attribution of the catalytic behaviors or reaction pathways. In addition, this review paper is also compared and summarized with a perspective on the future technical trends for the development of the different washcoat nanocatalysts in the autothermal reforming of methanol of microreactors for the fuel cell integrated systems.
Keywords: washcoat catalyst; metal loading; structure characterization; catalyst performance; microchannel; microreactor; micro fuel cell

Title: Direct liquid fuel cells
Author: Nie Luo
Affiliation: Dept. of Nuclear, Plasma and Radiological Engineering, UIUC
Abstract: Fuel cells (FC) were in the past mainly based on gaseous fuels. However, the storage issues associated with a gas, in particular hydrogen, have long been one of major obstacles holding back FC’s commercial applications. To address this problem, direct liquid fuel cells (DLFC) utilizing organic or chemical-hydride compounds rich in hydrogen are being actively investigated. One of the major advantages of a DLFC is the high density in energy storage. The direct use of the fuel at the catalytic electrodes also renders fuel reformers unnecessary. The removal of reformer reduces the mass and size of FC power systems making the DLFC especially attractive to mobile applications. The direct adoption of liquid fuels also generates a few unique issues for FC catalysts, membranes and stacks. This review summarizes the latest developments in this field with special attention on innovative techniques to address those issues. Improvements that may speed up the commercialization of this technology are also discussed.

Title: Advanced Modeling of Fuel Cell Systems
Authors: Sachin Puranik, Ali Keyhani and Farshad Khorrami
Abstract: In this paper, an architecture of a distributed generation system, different types of fuel cell systems, and modeling of 5-kW PEM fuel cell system are presented. As part of control problem, a nonlinear state space model of PEM fuel cell is developed based on physical processes of PEM fuel cell. A nonlinear autoregressive moving average model with external inputs (NARMAX) is also developed using recurrent neural networks. Both models are validated and simulated in MATLAB/Simulink and are used to analyze dynamic behavior of PEM fuel cell. The dynamic model of PEM fuel cell’s power conditioning unit is developed, and necessary control techniques are proposed to achieve desired performance of the overall PEM fuel cell system.

Title: Recent Advances in Enzymatic Fuel Cells: Experiment and Modeling
Authors: I. Ivanov ¹, T. Vidaković ², K. Sundmacher ^1,2
Affiliations: ¹ Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstr. 1, D-39106 Magdeburg, Germany
² Otto-von-Guericke-University Magdeburg, Process Systems Engineering, Universitätsplatz 2, D-39106 Magdeburg, Germany; E-Mail: vidakovi@mpi-magdeburg.mpg.de
Abstract: Enzymatic fuel cells convert the chemical energy of biofuels (e.g. glucose, other sugars, alcohols) into electrical energy. Unlike traditional fuel cell types which are mainly based on metal catalysts, the enzymatic fuel cells employ enzymes as catalysts. This fuel cell type can be used as an implantable power source for a variety of medical devices used in modern medicine to administer drugs, treat ailments and monitor bodily functions. It has some advantages in comparison to conventional fuel cells like a simple fuel cell design and lower cost of the main fuel cell components, but it suffers from severe kinetic limitations mainly due to inefficiency in electron transfer between the enzyme and the electrode surface. In this review article the major research activities concerned with the enzymatic fuel cells (anode and cathode development, system design, modeling) by highlighting the current problems (low cell voltage, low current density, stability) will be presented.

Type of Paper: Article
Title: Current Density Distribution Mapping in PEM Fuel Cells as an Instrument for Operational Measurements
Authors: Martin Geske, Maik Heuer, Günter Heideck and Zbigniew Styczynski
Affiliation: Otto-von-Guericke University Magdeburg, IESY/LENA, Germany; E-Mails: martin.geske@ovgu.de, maik.heuer@ovgu.de, guenter.heideck@ovgu.de, sty@ovgu.de
Abstract: The following work deals with the field of measurement systems for current distribution mapping for proton exchange membrane fuel cells (PEMFC). Taking into account already realized measurement systems, a method was chosen for the development of a measurement system. Hence it follows that a sensor and an electronic device for current distribution mapping was developed and analyzed. The sensor device was integrated in an existing PEM fuel cell stack to prove the functionality of the whole measurement system that is installed in an operating fuel cell system. For the acquisition of the current density distribution a sensor device was designed and installed within a multilayer printed circuit board with integrated sensors based on the chosen shunt resistors. Varying shunt values can be taken into consideration with the developed and evaluated calibration method. To visualize and save measurement data a software application was implemented. Its functionality was verified by operational measurements within a PEMFC system. Possible negative reactions of the sensor device and measurement accuracy are discussed in detail in the following work. The developed system enables operational measurements for different operating phases of PEM fuel cells. Additionally, this can be seen as a basis for new opportunities of optimization.
Keywords: PEM fuel cell; current density measurement device; etc.