scholarly journals Standardized Procedures Important for Improving Low-Temperature Ceramic Fuel Cell Technology: From Transient to Steady State Assessment

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1923
Author(s):  
Fan Yang ◽  
Yifei Zhang ◽  
Jingjing Liu ◽  
Muhammad Yousaf ◽  
Xinlei Yang
Keyword(s):  
Fuel Cells ◽  
Steady State ◽  
Fuel Cell ◽  
Power Density ◽  
Polarization Curve ◽  
Strain Curve ◽  
Transient State ◽  
Current Voltage ◽  
Real Performance ◽  
Ceramic Fuel

As the stress–strain curve of standardized metal samples provides the basic details about mechanical properties of structural materials, the polarization curve or current–voltage characteristics of fuel cells are vitally important to explore the scientific mechanism of various solid oxide cells aiming at low operational temperatures (below 600 °C), ranging from protonic conductor ceramic cells (PCFC) to emerging Semiconductor ionic fuel cell (SIFC)/Semiconductor membrane fuel cells (SMFC). Thus far, worldwide efforts to achieve higher nominal peak power density (PPD) at a low operational temperature of over 0.1 s/cm ionic conductivity of electrolyte and super catalyst electrode is the key challenge for SIFCs. Thus, we illustrate an alternative approach to the present PPD concept and current–voltage characteristic. Case studies reveal that the holy grail of 1 W/cm2 from journal publications is expected to be reconsidered and normalized, since partial cells may still remain in a transient state (TS) to some extent, which means that they are unable to fulfill the prerequisite of a steady state (SS) characteristic of polarization curve measurement. Depending on the testing parameters, the reported PPD value can arbitrarily exist between higher transient power density (TPD) and lower stable power density (SPD). Herein, a standardized procedure has been proposed by modifying a quasi-steady state (QSS) characterization based on stabilized cell and time-prolonged measurements of common I–V plots. The present study indicates, when compared with steady state value, that QSS power density itself still provides a better approximation for the real performance of fuel cells, and concurrently recalls a novel paradigm transformation from a transient to steady state perspective in the oxide solid fuel cell community.

Computer Models of Pem Fuel Cells for the Study of Transient Modes in Electrical Power Supply Complexes

2021 ◽  
Vol 64 (3) ◽  
pp. 60-67
Author(s):  
Ivan Vasyukov ◽  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Dynamic Response ◽  
Gradient Descent ◽  
Eddy Currents ◽  
Least Squares Method ◽  
Electrical Power ◽  
Computer Models ◽  
Pem Fuel Cells ◽  
Current Voltage

Static and dynamic computer models of fuel cells are considered. A static model is determined that most ac-curately reproduces the current-voltage characteristic of a real fuel cell. A method for tuning it according to the experimental I - V characteristic by the least squares method is proposed. A method for its adjustment ac-cording to the experimental I - V characteristic by the method of gradient descent is proposed. A modified elec-trical equivalent circuit of a fuel cell has been developed, which simulates its dynamic response, taking into ac-count the damping effect of eddy currents during operation of a stack of fuel cells on a pulse voltage converter. A method is proposed for determining the parameters of the model from the experimental oscillograms of the current and voltage of the stack. A universal model of a stack of fuel cells in LTspice has been developed, which makes it possible to simulate a dynamic response and, if necessary, simulate a real static I – V characteristic of the stack.

scholarly journals STEADY-STATE MODELLING OF PEM FUEL CELLS USING GRADIENT-BASED OPTIMIZER

10.6036/10099 ◽  
2021 ◽  
Vol DYNA-ACELERADO (0) ◽  
pp. [ 8 pp.]-[ 8 pp.]
Author(s):  
SALAH KAMAL ◽  
ATTIA EL-FERGANY ◽  
EHAB EHAB ELSAYED ELATTAR ◽  
AHMED AGWA
Keyword(s):  
Fuel Cells ◽  
Steady State ◽  
Fuel Cell ◽  
Optimization Problem ◽  
Pem Fuel Cells ◽  
Test Cases ◽  
Uncertain Parameters ◽  
Gradient Based ◽  
High Degree ◽  
Exchange Membrane

The accuracy of fuel cell (FC) models is important for the further numerical simulations and analysis at several conditions. The electrical (I-V) characteristic of the polymer exchange membrane fuel cells (PEMFCs) has high degree of nonlinearity comprising uncertain seven parameters as they aren’t given in fabricator's datasheets. These seven parameters need to be obtained to have the PEMFC model in order. This research addresses an up-to-date application of the gradient-based optimizer (GBO) to generate the best estimated values of such uncertain parameters. The estimation of these uncertain parameters is adapted as optimization problem having a cost function (CF) subjects to set of self-constrained limits. Three test cases of widely used PEMFCs units; namely, SR-12, 250-W module and NedStack PS6 to appraise the performance of the GBO are demonstrated and analyzed. The best values of the CF are 0.000142, 0.33598, and 2.10025 V2 for SR-12, 250-W module and NedStack PS6; respectively. Furthermore, the assessment of the GBO-based model is made by comparing its obtained results with the experiential results of these typical PEMFCs plus comparisons to other methods. At a due stage, many scenarios as a result of operating variations in regard to inlet regulation pressures and unit temperatures are performed. The copped reported results of the studied scenarios indicate the effectiveness of the GBO in establishing an accurate PEMFC model.

Improvement in Power Density of Protonic Ceramic Fuel Cells with Yb Doped BaZrO3 Electrolyte

2021 ◽  
Vol 103 (1) ◽  
pp. 1725-1734
Author(s):  
Hiroyuki Shimada ◽  
Yuki Yamaguchi ◽  
Hirofumi Sumi ◽  
Katsuhiro Nomura ◽  
Woosuck Shin ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Power Density ◽  
Ceramic Fuel ◽  
Ceramic Fuel Cells

scholarly journals Measurements Based Analysis of the Proton Exchange Membrane Fuel Cell Operation in Transient State and Power of Own Needs

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 498
Author(s):  
Andrzej Wilk ◽  
Daniel Węcel
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Transient State ◽  
Experimental Tests ◽  
Cell System ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Variable Load ◽  
Exchange Membrane

Currently, fuel cells are increasingly used in industrial installations, means of transport, and household applications as a source of electricity and heat. The paper presents the results of experimental tests of a Proton Exchange Membrane Fuel Cell (PEMFC) at variable load, which characterizes the cell’s operation in real installations. A detailed analysis of the power needed for operation fuel cell auxiliary devices (own needs power) was carried out. An analysis of net and gross efficiency was carried out in various operating conditions of the device. The measurements made show changes in the performance of the fuel cell during step changing or smooth changing of an electric load. Load was carried out as a change in the current or a change in the resistance of the receiver. The analysis covered the times of reaching steady states and the efficiency of the fuel cell system taking into account auxiliary devices. In the final part of the article, an analysis was made of the influence of the fuel cell duration of use on obtained parameters. The analysis of the measurement results will allow determination of the possibility of using fuel cells in installations with a rapidly changing load profile and indicate possible solutions to improve the performance of the installation.

Optimization of the Operating Parameters of a Proton Exchange Membrane Fuel Cell for Maximum Power Density

2005 ◽  
Vol 2 (2) ◽  
pp. 121-135 ◽  
Author(s):  
A. Mawardi ◽  
F. Yang ◽  
R. Pitchumani
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Design Parameters ◽  
Membrane Thickness ◽  
Exchange Membrane

The performance of fuel cells can be significantly improved by using optimum operating conditions that maximize the power density subject to constraints. Despite its significance, relatively scant work is reported in the open literature on the model-assisted optimization of fuel cells. In this paper, a methodology for model-based optimization is presented by considering a one-dimensional nonisothermal description of a fuel cell operating on reformate feed. The numerical model is coupled with a continuous search simulated annealing optimization scheme to determine the optimum solutions for selected process constraints. Optimization results are presented over a range of fuel cell design parameters to assess the effects of membrane thickness, electrode thickness, constraint values, and CO concentration on the optimum operating conditions.

Glucose Oxidation by Nano-Fibrous Anodes in a Fuel Cell

2008 ◽  
Author(s):  
Pinchas Schechner ◽  
Eugenia Bubis ◽  
Hana Faiger ◽  
Eyal Zussman ◽  
Ehud Kroll
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Peak Power ◽  
Open Circuit Voltage ◽  
Volume Ratio ◽  
Open Circuit ◽  
High Area ◽  
Micrometer Size ◽  
Oxidation Of Glucose

This work adds more experimental evidence regarding the feasibility of using glucose to fuel fuel-cells with anodes that have a high area-to-volume ratio. Electrospinning was used to fabricate sub-micrometer size fibrous electrocatalytic anode membranes for the oxidation of glucose in an alkaline fuel cell (AFC). The fibers of the membranes were made of polyacrylonitrile (PAN) and coated with silver by electroless plating. The anodes were tested while installed in a membranless fuel cell. The results presented include the open circuit voltage, OCV, the polarization curve, the power density as a function of the current density, and the peak power density, PPD. The measurements were performed with constant concentrations of glucose, 0.8 M, and KOH electrolyte solution, 1M. The performance of the anodes was found to improve as the diameter of the silver-plated fibers decreased. The highest PPD of 0.28 mW/cm2 was obtained with an anode made of plated fibers having a mean fiber diameter of 130 nanometers. We conclude from the results that saccharides in general, and glucose in particular, can serve as fuels for fuel cells, and that silver-plated polymeric electrospun electrodes have advantages due to their large surface area.

scholarly journals Using Shewanella Oneidensis MR1 as a Biocatalyst in a Microscale Microbial Fuel Cell

2013 ◽  
Author(s):  
Jie Yang ◽  
Sasan Ghobadian ◽  
Reza Montazami ◽  
Nastaran Hashemi
Keyword(s):  
Power Generation ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Power Density ◽  
Microbial Fuel Cells ◽  
Shewanella Oneidensis ◽  
Proton Exchange ◽  
Carbon Cloth ◽  
Anode Chamber

Microbial fuel cell (MFC) technology is a promising area in the field of renewable energy because of their capability to use the energy contained in wastewater, which has been previously an untapped source of power. Microscale MFCs are desirable for their small footprints, relatively high power density, fast start-up, and environmentally-friendly process. Microbial fuel cells employ microorganisms as the biocatalysts instead of metal catalysts, which are widely applied in conventional fuel cells. MFCs are capable of generating electricity as long as nutrition is provided. Miniature MFCs have faster power generation recovery than macroscale MFCs. Additionally, since power generation density is affected by the surface-to-volume ratio, miniature MFCs can facilitate higher power density. We have designed and fabricated a microscale microbial fuel cell with a volume of 4 μL in a polydimethylsiloxane (PDMS) chamber. The anode and cathode chambers were separated by a proton exchange membrane. Carbon cloth was used for both the anode and the cathode. Shewanella Oneidensis MR-1 was chosen to be the electrogenic bacteria and was inoculated into the anode chamber. We employed Ferricyanide as the catholyte and introduced it into the cathode chamber with a constant flow rate of approximately 50 μL/hr. We used trypticase soy broth as the bacterial nutrition and added it into the anode chamber approximately every 15 hours once current dropped to base current. Using our miniature MFC, we were able to generate a maximum current of 4.62 μA.

Controlling fuel crossover and hydration in ultra-thin proton exchange membrane-based fuel cells using Pt-nanosheet catalysts

2014 ◽  
Vol 2 (39) ◽  
pp. 16416-16423 ◽  
Author(s):  
Rujie Wang ◽  
Wenjing Zhang ◽  
Gaohong He ◽  
Ping Gao
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Exchange Membrane

A fuel cell with a 9 μm thick proton exchange membrane bearing Pt-nanosheet catalysts delivered 200% more power density as compared with a fuel cell with commercial Nafion® 211 membrane.

scholarly journals Application of platinum-cobalt-boron as the anode material for sodium borohydride-hydrogen peroxide fuel cells

Chemija ◽  
2018 ◽  
Vol 29 (4) ◽  
Author(s):  
Aldona Balčiūnaitė ◽  
Zita Sukackienė ◽  
Loreta Tamašauskaitė-Tamašiūnaitė ◽  
Rimantas Vaitkus ◽  
Eugenijus Norkus
Keyword(s):  
Hydrogen Peroxide ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Anode Materials ◽  
Peak Power ◽  
Anode Catalysts ◽  
Fuel Cell Performance ◽  
Peak Power Density ◽  
Density Values

The electroless deposition and galvanic displacement methods were used for the fabrication of cobalt–boron (CoB) catalysts modified with small amounts of platinum crystallites in the range of 9.8 to 14.4 μgPt cm–2. The prepared catalysts were studied as the anode materials for direct borohydride–hydrogen peroxide (NaBH4/H2O2) fuel cells at temperatures of 25–55°C. Polarization curves have been recorded with the aim to evaluate the fuel cell performance using the prepared CoB and that modified with Pt crystallites as the anode catalysts. For all catalysts (pure CoB and PtCoB) investigated, the peak power density values increase consecutively with the increment in temperature from 25°C up to 55°C. The values from 86–146 mV cm–2 and 146–234 mV cm–2 were determined for pure CoB and PtCoB catalysts, respectively. The highest specific peak power density of 21.5 kWgPt–1 was achieved at 55°C temperature when the PtCoB catalyst with the Pt loading of 9.8 μgPtcm–2 was employed as the anode catalyst in the NaBH4/H2O2 single fuel cell.

scholarly journals PENGARUH JENIS ELEKTRODA TERHADAP POWER DENSITY PADA MICROBIAL FUEL CELL DENGAN PENAMBAHAN GRANULAR ACTIVATED CARBON

2020 ◽  
Vol 12 (2) ◽  
pp. 1-9
Author(s):  
Vidia Wahyu Meidy Safitri ◽  
Tuhu Agung Rachmanto
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Power Density ◽  
Microbial Fuel Cells ◽  
Liquid Waste ◽  
Electrical Energy ◽  
Organic Content ◽  
Energy Utilization ◽  
Pre Treatment

ABSTRAK Limbah cair tahu mengandung kandungan organik tinggi dengan konsentrasi COD 1408 mg/l, TSS 191 mg/l dan pH 4,46.  Salah satu penelitian dengan pemanfaatan limbah dan energi yaitu Microbial Fuel cell (MFC). Energi Kimia senyawa organik dari mikroorganisme akan dirubah menjadi energi listrik dengan reaksi katalik dari mikroorganisme dalam keadaan anaerob merupakan proses microbial fuel cells. Salah satu tantangan untuk mengembangkan sistem MFC adalah dengan memilih elektroda yang tepat. Elektroda yang digunakan harus memiliki daya konduktifitas listrik tinggi, pemukaan yang luas, non korosif, biokompatibel, stabil. Penelitian ini bertujuan untuk memgetahui jenis elektroda optimum dalam menghasilkan power density dengan variasi elektroda karbon grafit, seng dan tembaga, variasi waktu 0, 48, 96, 144, dan 192 jam. Dilakukan pre-treatment koagulasi flokulasi. Hasil penelitian menunjukkan bahwa MFC dengan elektroda karbon grafit dan karbon grafit menghaslikan power density sebesar 2292,994 mW/m2. MFC juga menurunkan konsentrasi COD hingga 88%. Waktu pengolahan dapat mempengaruhi efisiensi penyisihan COD.   Kata kunci: limbah tahu, microbial fuel cell, power density   ABSTRACT   Tofu liquid waste contains high organic content with a COD concentration of 1408 mg / l, TSS 191 mg / l and pH 4.46. One of the researches related to waste and energy utilization is Microbial Fuel cell (MFC). Chemical energy organic compounds from microorganism will be converted into electrical energy by the catalytic reaction of microorganism in anaerobic conditions is a process of microbial fuel cells. One of the challenges to developing an MFC system is to choose the right electrodes. The electrodes used must have high electrical conductivity, a wide surface, non-corrosive, biocompatible, stable. This study aims to find out the most optimum type of electrode in producing power density with variations of carbon graphite, zinc and copper, variations of 0, 48, 96, 144, and 192 hours. The pre-treatment are Coagulation-flocculation. The results showed that MFC with carbon graphite and carbon graphite electrodes produced a power density of 2292,994 mW/m2. MFC also reduces COD concentrations up to 88%. Processing time can affect the efficiency of COD removal.   Keywords: Tofu Liquid Waste, Microbial Fuel Cells, power density

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