PEM Fuel Cell Stack Research Articles

Performance Analysis of a PEM Fuel Cell Stack Having 150 cm2 Active Layer by Using Design of Experiments (DOE)

In this study, the effects of operating parameters on power density of a 3-cell PEMFC (Polymer Electrolyte Membrane Fuel Cell) stack with serpentine flow channels having 150 cm2 total active layer have been examined experimentally. Desing Expert, which is the experimental design program (trial version) was used, and the data obtained as a result of the experiments were analyzed by entering this program. A total of 25 experiments were carried out according to the design created with the data entered into the program within the specified operating conditions range. The independent variables were entered which are cell temperature, humidification temperature, H2 flow rate and O2 flow rate, and the response is the power density. In this study, the hydrophobic cell stack which has the highest cell performance of which was previous studies results was used. In the optimization study, keeping the power density and maximum H2 flow to a minimum, the most suitable values are cell temperature 57.826°C, humidification temperature 56.151°C, O2 flow 1.587 L/min. Finally 432.398 mW/cm2 power density value was obtained under these operating conditions.

Micro-cogeneration application of a high-temperature PEM fuel cell stack operated with polybenzimidazole based membranes

High temperature Proton Exchange Membrane Fuel Cells (HT-PEMFC) have attracted the attention of researchers in recent years due to their advantages such as working with reformed gases, easy heat management and compatibility with micro-cogeneration systems. In this study, it is aimed to designed, manufactured and tested of the HT-PEMFC stack based on Polybenzimidazole/Graphene Oxide (PBI/GO) composite membranes. The micro-cogeneration application of the PBI/GO composite membrane based stack was investigated using a reformat gas mixture containing Hydrogen/Carbon Dioxide/Carbon Monoxide (H2/CO2/CO). The prepared HT-PEMFC stack comprises 12 cells with 150 cm2 active cell area. Thermo-oil based liquid cooling was used in the HT-PEMFC stack and cooling plates were used to prevent coolant leakage between the cells. As a result of HT-PEMFC performance studies, maximum 546 W and 468 W power were obtained from PBI/GO and PBI membranes based HT-PEMFC stacks respectively. The results demonstrate that introducing GO into the PBI membranes enhances the performance of HT-PEMFC technology and demonstrated the potential of the HT-PEMFC stack for use in micro-cogeneration applications. It is also underlined that the developed PBI/GO composite membranes have the potential as an alternative to commercially available PBI membranes in the future.

Formation Challenges of Lithium-Ion Battery Manufacturing

David Wood is a Senior Staff Scientist and University of Tennessee Bredesen Center Adjunct Faculty Member at Oak Ridge National Laboratory (ORNL), researching novel electrode architectures, mass transport phenomena, solid-liquid surface chemistry, advanced processing methods, manufacturing science, and materials characterization for low-temperature fuel cells, PEM electrolyzers, and lithium-ion batteries, and has been employed there since 2009. He is also the former ORNL Fuel Cell Technologies Program Manager (2011–2018), the former Roll-to-Roll Manufacturing Team and Group Leader (2015–2017), and a well-known energy conversion and storage researcher with an industrial and academic career that began in 1995. From 1997 to 2002, he was employed by General Motors Corporation and SGL Carbon Group, excelling at applied R&D related to automotive and stationary PEFC technology. Later work (2003–2009) at Los Alamos National Laboratory (LANL) and Cabot Corporation focused on elucidation of key chemical degradation mechanisms, development of accelerated testing methods, and component development. Dr. Wood received his BS in Chemical Engineering from North Carolina State University in 1994, his MS in Chemical Engineering from the University of Kansas in 1998, and his PhD in Electrochemical Engineering from the University of New Mexico in 2007. He was part of two LANL research teams that won the DOE Hydrogen Program R&D Award for outstanding achievement in 2005 and 2009. He was also part of the Cabot Corporation Direct Methanol Fuel Cell team, which won the Samuel W. Bodman Award for Excellence in 2008. Dr. Wood was also the 2011 winner of the ORNL Early Career Award for Engineering Accomplishment and led a team that won both a 2013 R&D 100 award and 2014 Federal Laboratory Consortium (FLC) award with Porous Power Technologies. He has received 19 patents and patent applications, authored 93 refereed journal articles and transactions papers, and authored 2 book chapters. Jianlin Li is a R&D Staff and University of Tennessee Bredesen Center Adjunct Faculty Member at Oak Ridge National Laboratory (ORNL). His research interest lies in materials synthesis, processing and characterization, electrode engineering, and manufacturing for energy storage and conversion. Dr. Li received his BS in Materials Chemistry and his MS in Materials Science from University of Science and Technology of China in 2001 and 2004, respectively, and his PhD in Materials Science and Engineering from the University of Florida in 2009. He is a recipient of several prestigious awards including two R&D 100 awards and one Federal Laboratory Consortium (FLC) award. He has received 14 patents and patent applications and authored 96 refereed journal articles and 3 book chapters. Seong Jin An is a Principal Engineer at Samsung Electronics leading rechargeable battery platforms for smartphone applications and has been employed there since late 2017. He had researched solid electrolyte interphase (SEI) in the lithium-ion battery as a guest at Oak Ridge National Laboratory (ORNL) (2014–2017). He worked at Samsung SDI in South Korea as a senior engineer developing PEM fuel cell stacks (2003–2011) and GS Fuel Cell in South Korea developing fuel processors for PEM fuel cell systems (2001–2003). He received his BS in Chemical Engineering from Seoul National University of Science and Technology in 1999, his MS in Chemical Engineering from Yonsei University, Seoul in 2001, his MS in Mechanical Engineering from Carnegie Mellon University, Pittsburgh in 2014, and his PhD in Energy Science & Engineering from University of Tennessee, Knoxville in 2017. He studied PEM fuel cells and lithium-ion batteries with fellowships during his MS and PhD programs. He has received over 200 patents and authored 21 refereed journal articles and transactions papers.

In-situ diagnostic tools for hydrogen transfer leak characterization in PEM fuel cell stacks part III: Manufacturing applications

This work describes a novel diagnostic technique for detection and isolation of manufacturing defects in polymer electrolyte fuel cell stacks. Two of the main causes of early stack failure are membrane pinholes and electric shorts. Membrane pinholes result in the local hydrogen crossover from anode to cathode, which reduces fuel utilization. With the growth of the pinhole, the crossed over hydrogen exits the cathode as hydrogen emission. When this emission passes the safe lower explosion limit of 4% hydrogen in air, the stack reaches its end of life (EOL). Alternatively, a low resistive point between the anode and cathode results in current flow through the contact point and local heat generation. This could burn the membrane and result in EOL of the fuel cell stack. A diagnostic technique is proposed to detect cells in which membrane pinholes or electric short occur. The technique allows both failure mechanisms to be isolated by means of a straightforward algorithm. The detection of the failure can be used as a pass/fail criterion during fuel cell stack manufacturing, whereas the isolation of the failure modes can be used to inform suitable repair procedures to be performed on the failed stacks.

The influence of electromagnetic field on the performance and operation of a PEM fuel cell stack subjected to a relatively low electromagnetic field intensity

Fuel cell technology is a promising alternative energy source which can provide cleaner environment and can satisfy part of the required energy demand. The objective of the present work is to investigate the influence of relatively low electromagnetic field (16 and 26 mT) on the operation and performance of a PEM fuel cell stack composite of multiple fuel cells. An electromagnetic coil was designed to enclose the fuel cell in the center of a ring. The magnetic field lines will surround the whole fuel cell stack. In this case the flow direction and the arrangement do not imply a certain direction relative to the fuel or air flow. Accordingly, the effect will extend to cover both cathodes and anodes. The results showed that electricity production of PEM fuel cells could be substantially promoted by applying magnetic fields even at relatively low magnetic strength. The fuel cell stack showed an enhancement in its efficiency by about 10% when exposed to the magnetic force. It was found also that the magnitude of the magnetic intensity has greater impact relative to the magnetic field direction which did not affect the stack performance.

Feature identification using acoustic signature of Ocean Researcher III (ORIII) of Taiwan

Feature identification using acoustic signature of Ocean Researcher III (ORIII) of Taiwan

Performance evaluation of PEM fuel cell stack on hydrogen produced in the oil refinery

The global progress in pushing the clean energy initiatives can be seen both as a challenge and opportunity for energy companies. Inclusion of “Hydrogen” as a value-added product from the refineries and use of fuel cells in the energy mix of an oil company, presents such an opportunity. However, the refinery hydrogen is not a fuel cell grade due to inherent impurities like carbon monoxide, carbon dioxide and methane are associated owing to the hydrocarbon source of production. In this study, a Low-temperature PEM fuel cell stack with 30 cells and active area of 50 cm2 was optimized on neat hydrogen in terms of its operating parameters including temperature, pressure and relative humidity. Upon optimization, the contamination tests were performed by doping various concentrations contaminants for simulating the refinery hydrogen composition. The results of performance evaluation with neat hydrogen and the impact of different contaminants are discussed in this study.

Process modeling of an automotive pem fuel cell system

ABSTRACTA system level, steady-state thermodynamics model for an automotive PEM fuel cell system was developed to investigate the effects of vehicle speed and operating pressure on the size of the system components, heat and water formation, fuel consumption, fuel cell, and system efficiency. Moreover, the consequences of the choices of membrane’s thickness and ionic conductivity on thermal and system efficiencies as a function of vehicle speed are analyzed. The model consists of a PEM fuel cell stack model and supplementary models for all necessary auxiliary components. Results show that increasing the system pressure has a significant positive impact on the water balance characteristics of the system, since less water is needed to reach the required relative humidity levels for the reactants. On the other hand, the high-pressure system requires more power in order to operate the compressor, which in turn, decreases the system efficiency. Decreasing air stoichiometry at high operating pressures improves the water management but has no effect at low pressures. Results also show that increasing the membrane’s ionic conductivity and decreasing its thickness enhances the system efficiency especially at higher vehicle speeds. Lastly, it is obtained that the system efficiency decreases as the vehicle speed increases.

Experimental study on performance evaluation of PEM fuel cell by coating bipolar plate with materials having different contact angle

Bipolar plates that have generally been made of graphite or composite materials are a fuel cell component that must be mechanically durable, easy to process, corrosion resistant, electrically and thermal conductive in contact with a gas diffusion layer, which is a porous material. In this study, instead of developing new materials with above features, water management has been improved by coating the bipolar plates and performance review has been carried out experimentally. The flow channels of the bipolar plates were coated with PTFE and SiO2. Physical vapor deposition (PVD) was used as the coating method. After the coating process, 120.2° contact angle with PTFE and 35° contact angle with SiO2 was approximately obtained in the flow channels. Single cell and 3-cell stack tests were performed with bipolar plates coated with these materials and uncoated polymer composite bipolar plates for given variable O2 and H2 flow rate and cell temperature at constant humidification conditions. 3-cell stack were tested after assembly. In PEM fuel cell stack tests, the highest current and power density values were also obtained in the hydrophobic PTFE coated plates. But in hydrophilic fuel cell stack, no voltage and current values could be measured due to the sudden decreases due to excessive flooding of the flow channels. A decrease in power density by 12.53% was observed when the single cell having hydrophobic flow channels with coated PTFE compared to 3-cell stack at the same operating conditions.

Vanadium redox flow batteries application to electric buses propulsion: Performance analysis of hybrid energy storage system

Abstract This paper presents a comparison between different battery energy storage systems (ESS) suitable for an urban electric bus. The investigation starts from a daily energy consumption analysis of a bus route in term of batteries state of charge (SOC). Specifically, three different ESS configurations are modelled basing on experimental data: LiFePO4 battery pack, LiFePO4 battery coupled with PEM fuel cell stack and a hybrid battery system composed by LiFePO4 and vanadium redox flow batteries (VRFBs). Moreover, authors provide an evaluation about the battery life through the application of the rainflow-counting algorithm on the yearly SOC trends of each system. As result, the proposed analysis highlights the favorable effect on the ESS due to the introduction of VRFB in the system. The improvements are found both on the net daily operating hours (one hour longer than the conventional case) and on the life expectancy of the LiFePO4 battery (over 9 years, with a gain factor of 5). The obtained results can be considered as a starting point for a wider study focused both on the ESS sizing and on the routes planning of a city buses fleet.

Online Flooding and Dehydration Diagnosis for PEM Fuel Cell Stacks via Generalized Residual Multiple Model Adaptive Estimation-Based Methodology

<div class="section abstract"><div class="htmlview paragraph">For proton exchange membrane fuel cell (PEMFC) stack, critical issues such as flooding and dehydration, are caused by improper water management. With respect to the water management failure, PEMFC stack outputs power and efficiency decreased. Therefore, proper water management with diagnosis contributes to the reliability and durability. Existing researches establish Electrochemical Impedance Spectroscopy (EIS) measurement to detect and identify different faults, whereas the sophistication, overwhelmed computational consumption of EIS and unaffordable dedicated instrumentation make it’s unsuitable for commercial application. Therefore, EIS is not considered to be a viable solution to online and real-time diagnostic scheme. In this paper, an innovative method based on EIS, is further developed to identify some critical PEMFC fault conditions online, wherein generalized residual multiple model adaptive estimation (GRMMAE) methodology is applied. The diagnosis process consists of multiple equivalent circuit models that represent signature faults separately, such as flooding and dehydration, causing significant variation of model parameters. Applying a small sinusoidal alternating current (AC) as a perturbation signal to various parallel models and measuring the potential response, whilst the noise from perturbation signal and measurement result in utilizing standard Kalman filters (KF) to generate residual signals. The residual signals are used in the GRMMAE methodology to evaluate probabilities in real-time that determine the type of fault. Simulation result shows that the fault conditions can be detected and identified accurately, hence the effectiveness of the proposed method would be indicated.</div></div>

2 kW Modular PEM fuel cell stack for space applications: Development and test for operation under relevant conditions

A polymer electrolyte fuel cell stack of 2 kW of peak power has been designed, manufactured and tested. Such a fuel cell stack has been envisaged to be applied for manned lunar exploration missions, as secondary energy source for both mobile vehicles and fixed power plants. The stack has been bread-boarded in order to test and demonstrate the technology. The following constraints have been considered during the study: (i) operation with pure hydrogen and oxygen (ii) low humidification levels (iii) use of commercial Membrane Electrode Assemblies. The breadboard has been made consisting of two modules, each of 500 W of nominal power. Specific tests have been conducted to prove the effect of gravity on the breadboard performance and verify its ability to follow variable load profiles over time, representative of different lunar surface exploration missions. The bread-board has shown a good performance during the test campaign, even if some failures of the Membrane Electrode Assemblies have been observed. The study has demonstrated the high performance of the developed stack and the potential of fuel cell technology for use in future human lunar exploration missions. At the same time, it has highlighted serious criticalities related to the reliability and robustness of the commercially available Membrane Electrode Assemblies, which need to be investigated further, before the use of this technology in a real space exploration mission can be possible.

Commercial vehicle auxiliary loads powered by PEM fuel cell

The commercial vehicles are in leadership in emission production for on-road vehicles. This high rate of emission is released in highly populated areas where diesel driven internal combustion engines are running in inefficient operating ranges. Except the propulsion, the internal combustion engine is powering the auxiliary devices such as refrigerator unit, etc. The auxiliary units are significant contributor to the overall pollutant production. In this paper the auxiliary load power supply for refrigerator unit is shifted from internal combustion engine to PEM fuel cell. The decrease in CO2 accumulated emissions was estimated by simulation model containing vehicle model (tire, brake, differential, gearbox and driver model), diesel engine model and auxiliary power demand model. Four stroke diesel engine was modeled and investigated. For this investigation the fully filled truck was used for simulating 100% weight load. The gross weight is 7500 kg.The novelty of the approach is the simulation performed on realistic combination of city and urban road cycle. The focus was on modelling the realistic truck driving cycle in order to correctly predict emission and fuel consumption reduction. Since initial investigation are performed on constant load demand of fuel cell, simplified model of PEMFC was applied. PEM fuel cell stack was designed in order to meet the demands of auxiliary consumers. The H2 consumption and size of hydrogen tank was estimated based on assumed 8-h daily drive. Finally, the migration of power supply for auxiliary units on commercial vehicle from internal combustion engine showed potential of fuel savings and CO2 reduction of up to 9% for a given case on this specific test cycle.

Electric motor-glider powered by a hydrogen fuel cell stack

The paper presents the current development of the AOS-H2 electric motor-glider project. The project encompasses the design and manufacture of an electric propulsion system (EPS) and a CF/epoxy airframe to be used as a flying test platform for the designed EPS. A 40-kW electric motor is supplied by a 10-kW PEM fuel cell stack and a Li-ion battery during run-up and ascent and by the fuel cell stack alone during steady flight. The airframe and the EPS have been completed; the results of bench tests of the EPS have proved that it meets the established requirements..

Experimental evaluation of a passive fuel cell/battery hybrid power system for an unmanned ground vehicle

Abstract Unmanned vehicles are increasing the performance of monitoring and surveillance in several applications. Endurance is a key issue in these systems, in particular in electric vehicles, powered at present mainly by batteries. Hybrid power systems based on batteries and fuel cells have the potential to achieve high energy density and specific energy, increasing also the life time and safe operating conditions of the power system. The objective of this research is to analyze the performance of a passive hybrid power system, designed and developed to be integrated into an existing Unmanned Ground Vehicle (UGV). The proposed solution is based on six LiPo cells, connected in series, and a 200 W PEM fuel cell stack, directly connected in parallel to the battery without any limitation to its charge. The paper presents the characterization of the system behavior, and shows the main results in terms of performance and energy management.

Study of Efficiency Characteristics of Interior Permanent Magnet Synchronous Motors

A four-module PEM fuel cell stack was electrochemically characterized prior to its incorporation to a hybrid power plant of an electrical utility vehicle. The 3 kW fuel cell stack, comprised of 4 units of 100 membrane electrode assemblies (MEAs) in an open-cathode and air-cooled configuration, was characterized in order to identify its optimum operational parameters. The open cathode configuration is a common approach to reduce parasitic loads and increase energy efficiency in fuel cells; however, the forced convection derives frequently to internal dehydration. Voltage reversal caused by lack of reactants, many times due to dehydration at the reaction sites (membrane-electrode interface) is a common failure source for this kind of configuration especially at high current demands. Therefore, water management becomes crucial for preventing fuel cell’s performance decrease and permanent failure. Subsequently, a smart water management strategy had to be established prior to the power plant integration into the vehicle for the fuel cell’s performance to be guaranteed during the vehicle duty cycle. For this purpose, a testing protocol was established for testing each module based on linear voltammetries, electrochemical impedance spectroscopy and thermal images in order to observe cell’s voltage and resistance as indicators of internal hydration, reactants concentration, and heat distribution during the stack operation. Polarization curves were obtained for each module and from them, the point (voltage, current, temperature and air vent) for steady operation was identified as the recommended condition for nominal performance during the fuel cell operation in the hybrid power plant of the electrical vehicle.

Hybrid System of Proton Exchange Membrane Fuel Cell (PEMFC) with Battery for Portable Power Supply

Background/Objectives: The combustion of fossil fuels and increased number of advanced technology leads to the global warming and climate change. So, to reduce the greenhouse gas emission and conserve the energy we need to use green energy like fuel cell and Li-ion battery system. This hybrid system consists of PEM fuel cell stack, Li-ion battery and bidirectional step up converter and can be used stationary as well as mobile equipment like vehicles.Methods/Statistical analysis: For the analysis of hybrid PEMFC/ Li-ion battery power supply system, portable embedded motor is proposed in this paper. The modeling, design, implementation and performance of hybrid system are demonstrate by using experimental results as well as MATLAB/Simulink.Findings: The simulation results shows that hybrid fuel cell-battery system could provide the continuous power to the sudden changing load and protect the devices. The results also shows that, bidirectional controller can successfully control the fuel cell output and maintain the state of charge of battery at a constant level which provides the significant efficiency of the hybrid power supply system and increased the life-cycle of the system more than 35%.Improvements/Applications: To improve the fuel cell system performance we need to provide the favorable conditions of temperature, pressure, humidity and control the flow rate of reactant gausses. Similarly, due to internal resistance, temperature, material used in manufacturing process, charging and discharging strategy reduces the efficiency as well as life of the battery pack. By using proper voltage balancing methodology we can maintain the similar voltage and prevent from irregular charging.

Modeling and design of PEM fuel cell stack based on a flow network method

Proton exchange membrane fuel cells are usually connected in series to form a fuel cell stack in order to satisfy the power demand of the practical applications. It is necessary to investigate the designs of the fuel cell stack to achieve the uniformity of reactant distributions and maximize the performance of the fuel cell stack. In this study, a fuel cell stack model is established based on the flow network method. The pressure and mass distributions of the reactant gas and coolant streams are determined by the flow network method incorporating the cross flow effect and the minor losses. The temperature distributions are also considered, and the individual cell performances in the fuel cell stack are obtained. The optimization of the fuel cell stack is also carried out after the stack model is validated by the experimental data. The flow channels are optimized in terms of the stack net power considering the pumping power losses and the cooling channels are optimized in terms of minimum power consumption for the same amount of cooling effect. Finally, the optimal designs for the fuel cell stack are obtained.

PowerCell wins more stack orders, secures bipolar plate supply

PowerCell Sweden has received a repeat order from a Chinese customer, who will test the S2 stack in commercial vehicles, and a prototype order for S3 stacks from an international Tier 1 supplier. The company has also signed an agreement with Dana Inc, securing the supply of high-quality bipolar plates for its PEM fuel cell stacks.

Toyota plans mass production of fuel cell stacks and hydrogen tanks, 10-fold increase from 2020

Toyota Motor Corporation has unveiled plans for two major new facilities in Aichi Prefecture, Japan to accelerate its production of fuel cell electric vehicles. A newly constructed building at the Honsha Plant in Toyota City will house PEM fuel cell stack production, while the Shimoyama Plant (No. 3) in neighbouring Miyoshi City will add a new line dedicated to mass production of high-pressure hydrogen storage tanks.