Water Management Strategies in Fuel Cell Systems

Abstract The current research status of fuel cells in the space field is first introduced, followed by an analysis of the comprehensive utilization mode of fuel cell energy from three aspects: water, gas, and heat. The fuel evaporated from the liquid hydrogen and liquid oxygen tanks of spacecraft can be used for fuel cell power generation. The heat generated by fuel cells can be used to preheat gases through a dual-channel heat exchanger, achieving thermal energy recovery for hydrogen and oxygen fuels. The water produced by fuel cells can be separated and recovered through static drainage for reuse in heating control or environmental control systems. A prototype of a fuel cell power generation system is designed and relevant performance tests are conducted. When the fuel cell system stably generates 400W of power, approximately 215W of waste heat can be reused. The utilization efficiency of hydrogen and oxygen fuels reaches over 97%, and the water recovery efficiency of the system reaches over 95%.

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Fuel cells, in combination with water electrolyzers and other renewable energy technologies promise to be an attractive near-future alternative to generate electricity in a direct, sustainable, and environmentally-friendly way.

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In recent years, fuel cells have gained prominence as a vital sustainable energy source. proton exchange membrane fuel cells (PEMFCs), utilizing hydrogen for electricity generation, have become especially widespread. However, addressing water management challenges remains crucial. Accumulated liquid water in the reaction area hampers reactant access, impacting the reaction rate and protonic conductivity, making effective water management pivotal for optimal PEMFC performance. The current work reports a comprehensive review of many methods to achieve efficient water management to attain higher fuel cell performance and increase its lifetime. Moreover, optimizing the operating conditions, using novel design configurations for the flow fields, and using new materials with specific surface treatment methods to fulfill this desired mission are discussed. A review of the methods used to visualize or model the water generation inside the flow channels and porous layers of PEMFCs is provided. In addition, the most recent water management methods, techniques, and materials are discussed. The ... Read More

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Regenerative fuel cells can operate alternately as an electrolyzer and as a fuel cell, frequently involving water as a reactant or product. Modifying the electrode surface to manipulate water can prevent electrode flooding and enhance the electrode's mass transfer efficiency by facilitating better contact with gaseous reactants. However, conventional electrodes face difficulties in allowing water droplets to penetrate in a single direction leaving electrodes. In this work to address this issue, a wettability gradient electrode is designed and fabricated for efficient water manipulation in regenerative fuel cells. The findings demonstrate that the water removal strategy in the electrolyzer mode yields the highest ammonia yield and Faradaic efficiency of 3.39 10-10 mol s-1 cm-2 and 0.49 %, respectively. Furthermore, in the fuel cell mode, the discharging process sustains for approximately 20.5 h, which is six times longer than the conventional strategy. The ability to sustain the discharging process for extended periods is particularly advantageous in regenerative fuel cells, as it e... Read More

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Energy Management Strategies for Fuel Cell Vehicles: A Comprehensive Review of the Latest Progress in Modeling, Strategies, and Future Prospects

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This paper investigates fuel cell technology, an efficient and environmentally friendly method for generating electricity by harnessing the energy content of hydrogen or alternative fuels. Fuel cells produce electricity with water, heat, and power as the only by-products when hydrogen is used as fuel, making them a clean and sustainable energy option. Future applications in the hydrogen economy are expected to utilize fuel cells as safe, quiet, and reliable energy sources. Fuel cells exhibit superior efficiency compared to combustion engines, promptly converting fuel energy into electrical energy. Various types and sizes of fuel cells with distinct technological requirements have been developed by scientists and inventors to enhance efficiency. The choice of electrolyte is a critical factor influencing the possibilities available to fuel cell inventors. Beyond exploring the technologys evolution, this paper delves into the diverse applications of fuel cells across different sectors. From transportation to industrial processes and residential power generation, fuel cells play a cruci... Read More

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Abstract This paper introduces the application demands and research progress of fuel cells in the space field. Subsequently, an analysis of the comprehensive energy utilization modes of fuel cells from the aspects of water, gas, and heat is conducted. The fuel evaporated from the liquid hydrogen and liquid oxygen tanks of spacecraft can be used for fuel cell power generation, and the heat generated by fuel cells, together with the low-absorption and low-emissivity thermal control coatings, maintains the temperature of the spacecraft in the shadow area. The product water from fuel cells can be purified for reuse in thermal control, environmental control, and water electrolysis cells. The hydrogen and oxygen produced by electrolyzing water can be recycled for fuel cell power generation, and the oxygen can also be used for environmental control and life support, while the hydrogen can be used for methane production. To reduce system weight and achieve comprehensive utilization of energy and resources, integrated system design and research on regenerative fuel cell system principles are ... Read More

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Controlling the relative humidity is crucial for improving fuel cell performance in self-humidifying fuel cells. In light of this, this study investigates the influence of humidity variation on Proton Exchange Membrane Fuel Cells (PEMFC) performance through single-cell testing and a two-dimensional two-phase model. In the experiment, different humidity conditions are achieved by adjusting the inlet air temperature, and the effect of relative humidity on cell performance is observed. The research findings indicate that as the relative humidity increases, the performance of the fuel cell gradually improves. Increasing humidity reduces voltage fluctuations, particularly at low flow rates, demonstrating more stable performance. Under different humidity conditions, when the inlet air flow rate exceeds a certain value, the voltage non-uniformity of the cell remains within 1, indicating insignificant voltage fluctuations, attributed to the effects of inlet air flow rate on performance improvement and alleviation of flooding phenomena. Analysis of the two-dimensional two-phase model reveals ... Read More

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Proton exchange membrane fuel cells (PEMFCs) are efficient and zero emission energy conversion technology with promising application prospects towards carbon neutrality. The PEMFC's performance is largely affected by the poor water management, which is a substantial concern for long term durability. Herein, we overview the water management problems in PEMFCs, such as flooding and dehydration of membrane electrode assembly and analyze the causes and their impacts on the device performance. Major problems such as flooding impedes the gas transport and electrode reactions, while dehydration increases the membrane resistance and hinders proton transport. We have thoroughly overviewed several electrochemical and physicochemical diagnostic techniques for water management in PEMFCs. Additionally, material development and optimization approaches for the flow field structural design are explored in order to improve mass transport and wetting characteristics for optimized water management. Therefore, it is anticipated that this review will provide insights into the effective operation of PEMFC... Read More

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Water management is crucial for achieving high-performance proton-exchange-membrane fuel cells (PEMFCs), as it helps keep the electrolyte hydrated while avoiding performance degradation and cell shutdown due to liquid-water accumulation. According to ex-situ measurements [1-3], accumulation of liquid water in gas-diffusion layers (GDLs) of PEMFCs is a transient process that can be accompanied with oscillations in capillary pressure and saturation. To understand how liquid-water accumulation and drainage impact PEMFC performance hysteresis and stability, a transient cell-level model that accounts for electrode structure and composition and is computationally efficient is needed. A number of volume-averaged models that describe the electrode structure through pore-size distribution have been developed in the past [4-7], but they are steady-state and thus cannot predict dynamic PEMFC performance. Existing transient models have also not been used to analyze cyclic liquid-water accumulation [8-10]. In this work, a transient two-phase 2D PEMFC model is developed in the open-source fuel-cel... Read More

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A fuel cell is a promising energy conversion system that will eventually become the first-choice for producing power because of its clean or zero-emission nature. A steady-state, two-dimensional mathematical model with a complete set of governing equations valid in different components of a PEM fuel cell was developed to illustrate the temperature and water content effects on proton exchange membrane (PEM) fuel cell performance. This model considers the transport of species and water along the porous media: gas diffusion layers (GDL) anode and cathode, and the membrane of PEMFC fuel cell. To improve the kinetics of electrochemical reactions at the electrodes and thus reduce the activation overvoltage: increase the gas diffusion electrodes reduce the drop ohmic, especially in the proton conductive membrane through an increase in ionic conductivity. The electrochemical performance of a fuel cell will be strongly depend temperature and water content.

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Water management is an important criterion in the operation of proton-exchange membrane fuel cells to maintain the high performance and reliability of the system. The water content in the cathode air that is supplied to the cathode channel contributes to the membrane humidification and the transport of protons inside the membrane structure. In automotive applications, the supply air is typically driven through an external membrane humidifier to absorb more moisture from the recirculated cathode exhaust. In the literature, humidifiers and fuel cell stacks have been separately investigated without considering whole-system configurations for water management. This study investigates changes in the cathode air characteristics through a membrane humidifier and compares two configurations using a humidifier bypass of the supply flow and exhaust flow to adjust the cathode inlet air relative humidity. Each component in the system was modeled using mathematical relations and converted into blocks of inputs and outputs in MATLAB/Simulink for simulation. The bypass valve was demonstrated to eff... Read More

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Now is the time for hydrogen, it is a new vector of energy independence, which is available to decarbonize several sectors of the world economy. Unfortunately, Hydrogen is only rarely present by electrolysis of water, which is an electrolytic process that, breaks down water (H2O) into di oxygen and hydrogen gas, using an electric current offered by a conventional or a renewable energy source. In fact, thanks to a water electrolyzer and a fuel cell, it is possible to switch from electricity to hydrogen and vice versa, without emitting any pollutant in situ. Beyond the obvious priority goals, such as reliability and lifespan, it can be difficult to predict how fuel cells will be used in the future. Several researches treated this phenomenon, and treated the Fuel cell. In this paper, we illustrate a modeling of an Exchanged Proton Membrane Fuel Cell (PEMFC), using Matlab/Simulink. This modeling will highlight the influence of different parameters on the efficiency of the PEMFC and the electricity produced.

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<div class="section abstract"><div class="htmlview paragraph">Fuel cells are considered one of the promising technologies as possible replacement of Internal Combustion Engine (ICE) for the transportation sector due to their high efficiency, ultra-low (or zero) emissions and for the higher drive range.</div><div class="htmlview paragraph">The Membrane Electrode Assembly (MEA) is what mainly influences the Fuel Cell FC performance, durability, and cost. In PEMFC the proton conductivity of the membrane is a function of the humidification level of the FC membrane, hence the importance of keeping the membrane properly humidified to achieve the best possible fuel cell performance. To have the optimal water content inside the fuel cells membrane several strategies could be adopted, dealing with the use of external device (such as membrane humidifier) or to adopt an optimal set of parameters (gas flow rate and temperature for example) to use the water produced at fuel cell cathode as humidity source.</div><div class="htmlview paragraph">The aim of this p... Read More

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Water management is a crucial aspect of hydrogen fuel cell operation because inadequate management can lead to significant losses in mass transport, limitations in oxygen diffusion, and membrane durability issues. This study investigates the impact of various operational conditions on the initial formation and evolution of liquid water content and distribution, as well as water evacuation, within a lung-inspired PEM fuel cell with a 50 cm2 active area. A series of experiments were conducted to assess the effects of cell pressure, relative humidity of the reactant (anode and cathode), temperature, and cell current density. Neutron imaging was utilized as it has been shown to be an effective technique for quantitative analysis of water distributions. The results indicate that water initially appears in the sponges located in the central region of the cathode, but due to considerable back-diffusion, water predominantly accumulates in the area of the anode channels in contact with the cathode sponges. The amount of water in the cell increases faster when the relative humidity of the cath... Read More

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Because of its clean or zero-emission nature, the PEM fuel cell is considered a potential energy conversion device for power production. The performance of the PEM fuel cell is known to be influenced by many parameters, such as operating temperature, pressure, and humidification of the reactants. In addition, the operational stability of the PEM fuel cell under these conditions with the purging of water during its operation should also be studied to understand the performance of the PEM fuel cell. Therefore, this paper brings out the effects of cell humidification and cell heating on the performance, especially the operational stability concerning the liquid water removal of the PEM fuel cell. The experiments are conducted on a single PEM fuel cell with mixed flow distributors operating on different cell temperatures and humidification conditions. At dry feed operation of the PEM fuel cell at ambient condition, the cell utilizes around 80.3% of water generated for its membrane hydration, i.e., self-humidification. When the PEM fuel cell is operated at full humidification (100% RH) on... Read More

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A good water management is very important for the operation of PEM fuel cell systems as the proton conductivity is dependent on the membrane water content. In contrast to state of the art approaches, this study focuses on an anode based water management approach of fuel cell systems with an anode recirculation loop. The aim of the anode based water management is to reach a high and homogeneously distributed anode humidity without condensation in all relevant operating conditions. A criterion is defined to evaluate the anode humidity distribution. A macroscopic discrete 2D+1D model was developed that can simulate humidity distributions and the cell voltage for various flow directions of the fluids and operating conditions. The model considers the system behavior including the anode recirculation loop. This study shows that flow directions that support an internal water circulation are beneficial for fuel cell systems without external humidification. Furthermore, the study shows a correlation between the anode humidity distribution at the membrane and the cell voltage. The higher the t... Read More

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Water management is a key factor in the operation of hydrogen fuel cells since its formation may lead to significant mass transport losses, oxygen diffusion limitation and membrane durability issues. In this work, the effect of different operating conditions on the liquid water distribution inside a 50 cm2 active area bio-inspired PEM fuel cell has been studied. Therefore, a set of experiments was designed varying cell pressure, the reactants relative humidity (anode and cathode), temperature, and cell current density. Liquid water distribution for each operating condition was determined using neutron imaging technique as it has been proved to be an excellent technique for this purpose, including quantitative analysis and water profiles in the different areas of the bio-inspired flow field. The results show that high relative humidity of the inlet gas flows, high pressure, low temperatures and low current density favor the accumulation of water in the flow field channels and GDL. Specifically, water accumulates preferentially in the anode side that make contact with the low part of t... Read More

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Fuel gas utilization and water management are particularly challenging integrated engineering problems in hydrogenoxygen proton exchange membrane fuel cell (H 2 /O 2 PEMFC) systems. Herein, a standardized process is adopted to evaluate the performance and investigate the degradation mechanisms of a PEMFC with dual exhaust gas recirculation. The purpose of incorporating recirculation subsystems in the fuel cell is to achieve a high fuel gas utilization rate and realize effective water management inside the stack, which consists of 3Dprinted ejectors and a customized recirculation pump. Evaluation of the electrochemical performance degradation and morphological characterization of the fuel cells under different operating strategies are performed after 50 h durability experiments. At a current density of 400 mA cm 2 , the performance degradation rates of the stack decrease from 16.50% to 7.49% and 0.71% in the ejector and recirculation pump operation strategies, respectively. The results show that using exhaust gas recirculation devices (ejector/pump) in the fuel cell stack can help ... Read More

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The processes for integrating polymer membrane fuel cells into automobiles are speeding up as a result of the automotive industry's rising investments in hydrogen technology on a daily basis. However, research on fuel cell technology focuses on enhancing its performance and efficiency. In order to counteract the drying effect under specific operating conditions, this study suggests a water management strategy involving active humidification. The membrane humidifier has been removed from the system, and a new water injection model has been developed in order to free the system's relative humidity, which is reliant on the operating point of the fuel cell and the efficiency of the humidifier, from these dependencies. The study investigates metrics such as current density, cell voltage, power, and efficiency against measurements of fuel cell performance, relative humidity, membrane water content, temperature, and water management. The proposed method has been created on the AVL CRUISE M simulation platform and using experimental data from the test bed, it has been observed that the temp... Read More

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The proton exchange membrane fuel cell, as a novel energy device, exhibits a wide array of potential applications. This paper offers a comprehensive review and discussion of modeling and control strategies for fuel cell systems. It commences with a concise introduction to the structure and principles of fuel cells. Subsequently, it outlines modeling approaches for various fuel cell subsystems, encompassing the fuel cell stack, air supply system, hydrogen supply system, thermal management system, and water management system. Following this, it conducts a comparative analysis and discussion of prevalent control strategies for the aforementioned subsystems. Lastly, the paper outlines future research trends and directions in the modeling and control strategies of fuel cells. The aim of this paper is to provide ideas and inspirations for the design and management of membrane fuel cell systems from control aspects.

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Load shedding could be a solution to water accumulation alleviation during the operation of proton exchange membrane fuel cell (PEMFC) engines. In this paper, multiple-step loading reduction strategies based on two laboratory-scale (25 cm2) single PEMFCs (assembled with triple-serpentine and single-serpentine flow field plates on the both electrodes and thus named after cell TS and cell SS respectively) are experimentally discussed and evaluated. The real-time pressure evolution and HFR are recorded, compared and analyzed to characterize water transfer phenomenon among the components. The investigation results suggest that: 1. From the perspective of output voltage and power after load reduction, the number of reduction step has little effect on the output performance; 2. Cell TS exhibits better homogeneous trend of pressure drop although with less water removal quantity comparing with that of cell SS, which is resulted from multi-channel configuration; 3. The cathode pressure drop of cell SS decreases obviously throughout the experiment, indicating the convinced water removal capabi... Read More

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The effective transportation of liquid water is one of the challenges faced by hydrogenoxygen proton exchange membrane fuel cells during operation, which has a significant impact on their performance and working life. In this work, a single cell with parallel flow field is designed for cathode liquid water image acquisition and high-resolution current density mapping based on transparent fuel cell technology combined with printed circuit board segmented fuel cell technology. By varying the loading current, the influence of the liquid water transport process on the local performance was investigated. The results show that the upper limit of the cathode liquid water coverage area in the parallel flow field is about 200 mm2, accounting for 16% of the channel area. In addition, combined with the current density distribution, it is found that the local performance degradation occurs when the liquid water coverage rate reaches 20%, and this phenomenon is more likely to occur downstream of the flow field. The results provide effective guidance for the formulation of reasonable water manage... Read More

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Water management is critical to the desirable and stable performance of a proton exchange membrane fuel cell (PEMFC) stack, especially under ultra-low inlet pressure. The three-dimensional transport characteristics of liquid water inside a PEMFC under different operating pressures are investigated by adopting the transparent single cell synchronous observation. High-speed camera technique based observed results indicate that the slug flow patterns tend to form under low operating pressure, which is challenging to be removed from the flow channels, thus reducing the output voltage under high current densities. However, this dilemma can be alleviated by modifying the contact angles of channel surfaces to get close to 110. Such channels facilitate the formation of liquid film flows, thereby unclogging the pathway for the transfer of reactant gases to the catalyst layer, ultimately enhancing the performance of fuel cells. Consequently, the 1.4 kW fuel cell stack can be operated stably for over 200 hours with a decay rate of less than 0.8% at 1A/cm current density, and the inter-stage o... Read More

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PEM fuel cell systems in automotive applications must provide a low minimum power compared to their maximum power. Especially systems without external humidification require a rather low stoichiometry and elevated pressure at the cathode to avoid dry-out at low load operation. Targeted experiments show that this may cause flooding, as the gas velocity becomes too low for sufficient liquid water drainage. An increase of the gas velocity would cause a membrane dry-out, negatively impacting the cells performance and lifetime. One solution for this issue is proposed in this work: a dynamic operation of the air system, which is periodically switched between one set point for membrane humidification and another one for liquid water drainage. A sophisticated experimental fuel cell system is used to test the proposed solution on a 100kW stack.

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Within the last decades, fuel cells have become the center of attention of research community, industry, and the general public. This is due to the emphasis on the sustainability of the society and the emerging concept of a hydrogen economy. Proton exchange membrane fuel cells (PEM FCs) represent a mature and established fuel cell technology. The flexibility of operation, the high degree of fuel utilization, and the output power density make them suitable for mobile applications such as hydrogen-fueled vehicles or on-site energy generation. Membrane electrode assembly (MEA) is the mainstay of the PEM FCs. The MEA consists of the proton exchange membrane, catalytic layers, and gas diffusion layers (GDLs). Single MEAs are interconnected by bipolar plates with flow field channels homogenously distributing reactants and realizing easy removal of the generated water. Individual cells are compressed together, forming the fuel cell stack. The GDL plays a three-fold role in the performance of PEM fuel cells. It has to offer good electrical conductivity, ensure good reactant distribution alon... Read More

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Water management in fuel cells is important for avoiding the phenomenon of flooding or dehydration in the stack and for maintaining good fuel cell performance and durability. This study focuses on the evaluation of the dynamic performance and behaviour (purge cycle) of the commercial Polymer Electrolyte Membrane (PEM) fuel cell stack towards water transport (water balance) at different operating conditions. The stack was operated at different current loads (010 A) and operating temperature (ambient to 50 C). The results indicated that the measured water accumulation in the stack increased with the increase in current load. The optimal current load was 4 A, with calculated efficiency of 62.8%. The optimal operating temperature was 40 C, resulting in calculated efficiency of 52.3%. At higher temperature, the fuel cell performance decreased, and the measured water balance was not properly distributed, which could be due to the dehydration and low conductivity of the electrolyte membrane. It can be concluded that the behaviour and performance of the stack, as well as the water balance... Read More

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The water content of fuel cell can be controlled by adjusting working conditions. Although the water content cannot be directly observed, the electrochemical impedance spectroscopy (EIS) data can be used to characterise the internal water content. In this paper, the EIS data of fuel cell are obtained through experiments. According to the results, changing the operating temperature has a significant impact on the low-frequency impedance. The temperature should be changed to avoid dehydration or flooding at different current density. The impedance of single cell shows that although the optimised temperature improves performance, there is still an imbalance of water content among the cells. This article also compares the effect of controlling relative humidity and working temperature. The comparison shows that the two solutions have close effects on the impedance. Considering various factors, controlling working temperature is an effective method of fuel cell water management.

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Water management in open-cathode PEM fuel cells is challenging due to direct supply of ambient air. In this contribution, the water transport mechanisms and local water distributions in open-cathode PEM fuel cells are studied using local current measurement and various electrochemical methods. The results show local membrane dehydration occurs and the water distribution is much uneven when current density is lower than 200 mA cm2. As operating current increases, the water content of membrane increases rapidly until the membrane is fully hydrated and the local water distribution also becomes more uniform. Whereas, liquid water begins to accumulate in gas diffusion layer and catalyst layer when the current density is over 700 mA cm2. Furthermore, the effects of operating conditions are investigated. On the one hand, when the current density is lower than 500 mA cm2, improving temperature and air velocity can reduce cell performance as too much water is removed out of fuel cell, leading to membrane dehydration. On the other hand, when the current density is above 600 mA cm2, increas... Read More

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Water management is essential to ensure high performance and stable operation of the proton exchange membrane fuel cell (PEMFC). However, little is known about water management in the hydrogen circulation anode (HCA) mode which can achieve high hydrogen utilization. In this work, the effects of hydrogen circulation rate, a key parameter of HCA mode, on water management and cell performance are experimentally investigated. In particular, transparent fuel cell and printed circuit board segmented fuel cell technologies are used to study the water distribution and the local current density distribution, respectively. Furthermore, the electrochemical properties and PEMFC stability at different hydrogen circulation rates are discussed in detail. The experimental results indicate that increasing the hydrogen circulation rate reduces liquid water in the cathode and anode flow channels, which can effectively alleviate the adverse effects of flooding on overall performance and cell stability. However, subsequent drying of the membrane and catalyst layer results in an increase in ohmic resistan... Read More

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Water management in various components of the proton exchange membrane fuel cell (PEMFC) is a significant and challenging issue affecting output performance. PEMFC utilizing dual ejector-based recirculation has been developed to evaluate and improve the performance and water transport properties. A detailed investigation into the effects of ejector operating conditions, such as primary flow pressure and secondary flow relative humidity, on the performance of PEMFC is conducted. The results show that significant performance improvement of PEMFC can be achieved by increasing the operating pressure. The power density can be increased by 37.8% and 86.5% with ejector primary flow pressures of 300 and 400 kPa, respectively. Furthermore, an optimization strategy integrating PEMFC operating condition is proposed to ensure the stability and lifespan of performance. The water management and integration optimization strategy obtained in this paper can provide valuable insight into options for improving the performance of PEMFC with dead-ended anode and cathode.

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Water management is critical in optimizing anion exchange membrane fuel cell (AEMFCs) performance and durability. The role of membranes on determining cell water balance in AEMFCs has received limited study. A more thorough understanding of membrane water transport parameters is necessary for thorough cell optimization. In this study, a novel method for probing limiting current based on water flux across an AEMFC is presented for the first time. The water limiting current has been investigated as a function of relative humidity of anode and cathode streams, cathode backpressure and cell operating temperature. From these studies, it is clearly shown that water diffusion through the membrane from the anode is the most critical mechanism for achieving high current density performance and durability. The developed method can act as a novel screening technique that focuses on the impacts of water transport parameters and helps identify promising membrane materials based on their water transport properties. A critical but underappreciated facet of AEMFC performance and durability.

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Exposing anion exchange membrane (AEM) fuel cells to ambient air is known to decrease fuel cell efficiency significantly due to the presence of CO 2 .

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Hydrogen energy and fuel cell technology are critical clean energy roads to pursue carbon neutrality. The proton exchange membrane fuel cell (PEMFC) has a wide range of commercial application prospects due to its simple structure, easy portability, and quick start-up. However, the cost and durability of the PEMFC system are the main barriers to commercial applications of fuel cell vehicles. In this paper, the core hydrogen recirculation components of fuel cell vehicles, including mechanical hydrogen pumps, ejectors, and gaswater separators, are reviewed in order to understand the problems and challenges in the simulation, design, and application of these components. The types and working characteristics of mechanical pumps used in PEMFC systems are summarized. Furthermore, corresponding design suggestions are given based on the analysis of the design challenges of the mechanical hydrogen pump. The research on structural design and optimization of ejectors for adapting wide power ranges of PEMFC systems is analyzed. The design principle and difficulty of the gaswater separator are s... Read More

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<p>Seiring peningkatan kebutuhan listrik di Indonesia serta menipisnya jumlah energi fosil dilakukan pengembangan energi baru terbarukan yang bebas polusi salah satunya yakni pemanfaatan energi hidrogen. Mesin fuel cell merupakan aplikasi pengembangan energi hidrogen yang dapat mengubah energi kimia menjadi energi listrik. Proton Exchange Membrane (PEM) fuel cell merupakan salah satu jenis fuel cell yang mampu beroperasi pada temperatur rendah dan menghasilkan efisiensi sekitar 40-60%. Pada penelitian sebelumnya kinerja dari mesin PEM fuel cell kurang maksimal, sehingga perlu dilakukan modifikasi pada bagian komponen HHO generator yakni dengan mengubah dari tipe wet cell menjadi dry cell. Pengubahan ini didasari kelemahan tipe wet cell dimana hasil debit gas hidrogen rentan tercampur dengan uap air akibat kenaikan temperatur pada larutan elektrolit sehingga menyebabkan terjadinya penguapan. Hasil dari modifikasi ini yakni debit gas hidrogen yang mana setelah dilakukan modifikasi pada arus masukan 20 A dan konsentrasi KOH 0,5 M terjadi peningkatan debit sebesar 0,306 mL/s, kemud... Read More

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Electricity is generated by the fuel cell device mounted in the vehicle, and the vehicle that powers the vehicle is called a fuel cell vehicle (FCV). Proton Exchange Membrane Fuel Cell (PEMFC) is currently the best performance among all fuel cells, which has high specific energy, low operating temperature, fast starting, no leakage, and other characteristics. This paper sorts out the research direction of proton exchange membrane and the principle of a fuel cell system and summarizes the technical characteristics of fuel cell vehicles, including safety systems, water management systems, power electronic systems, and dynamic topology optimization. It is concluded that there are still many technical problems and systems to be solved so far, and more suitable optimization and monitoring methods need to be explored. Finally, the application of this type of fuel cell vehicle is discussed, and its impact on the atmospheric environment and the life cycle of the manufacturing stage are evaluated. Fuel cell vehicles play an important role in improving the environment, but their development is... Read More

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This work is designed to study the energy management of a Proton Exchange Membrane Fuel Cell (PEMFC), which is based on the activity and management of water and its effect on the electrolyte membrane (FC) as a function of the influx of hydrogen and oxygen, by taking into account the influence of humidification on the implementation of this electrical system to avoid drying and flooding that can cause deterioration of the FC. The cell voltage and system efficiency are also influenced by current density and operating temperature, and simulation results on Matlab / simulink are discussed.

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It is widely acknowledged that the water balance issue is extremely important for improving the performance and durability of the proton exchange membrane fuel cell. In the presented paper, the visualization platform of the single fuel cell and the water balance model were built to investigate the water transport mechanisms. A transparent 25 cm2 single fuel cell with serpentine flow channels was adopted. Based on the experimental data, firstly, the change rate of water content in the fuel cell was calculated quantitatively and the reliability of the water balance model was rigorously validated. Then, the water state in the fuel cell as the qualitative finding was observed online to assist the research of water transport mechanisms. Finally, the effects of inlet gas temperature, inlet gas humidity, and hydrogen/air stoichiometry on the EIS, the voltage, and the water content in the fuel cell were studied quantitatively, respectively. The corresponding relationship between the performance and the water content in the fuel cell was obtained.

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Effective water management plays a significant role in improving the performance and lifetime of proton exchange membrane fuel cells (PEMFCs). The ejector can take full advantage of the huge pressure potential between the high-pressure fuel tank and the PEMFCs to realize fuel gas recovery, and it is usually adopted for the auxiliary drainage of hydrogen/oxygen stacks. In this study, the dynamic behavior of liquid water droplets in the cathode flow channel of a PEMFC operating in ejector-based recirculation mode was numerically investigated. The effects of the operating current density of the fuel cell as well as the pore size of the water inlet boundary on the droplet behavior were studied, and the number of contact surfaces between the droplet and the flow channel were investigated. The results show that the speed of water removal from the flow channel with ejector-based recirculation can be increased by 37.5% when the fuel cell operates at 1.0 A cm2. Moreover, the hydrophobic side and top surfaces are more suitable for water slug removal when the PEMFC operates at a high current d... Read More

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The water management is critical for the operation of PEM fuel cells and has a strong impact on its performance and durability. The aim of this work is the simulation-based investigation of the operation of a PEM fuel cell system with the special focus on its water management. In order to analyze these dependencies correctly, a 2-D + 1-D PEM fuel cell stack model has been developed, which on the one hand has a high level of modelling details and on the other hand meets high requirements concerning its runtime, to enable acceptable simulation times for fuel cell system simulations. The fuel cell model is integrated into an AVL Cruise-M fuel cell system simulation. An analysis is presented comparing a system operation with a fuel cell in co- and counter-flow configuration with a special focus on the local and overall water management.

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One of the products of the interaction between hydrogen and oxygen in a fuel cell is water. The presence of this product can reduce the efficiency of the fuel cell and causes problems in its operation. The present study aims to introduce a water level control system that can prevent the loss of reactant gases, such as hydrogen and oxygen, by improving the process of separation of water from these gases. Thus, unused gases are returned to the fuel cell, and as a result, the costs of using the reactant gases for producing electric power will be reduced. Although the process of a control system has been described qualitatively in previous studies, this paper is intended to quantify this procedure with respect to fuel cell specifications and construction limitations. This system consists of mechanical (venturi) and control units and is designed based on different reactant gases such as air and oxygen. The fuel cell pressure drop and maximum wasted volume of gases when using this system are less than 0.001 bar and 0.5% in each cycle, respectively. This system is simulated based on differe... Read More

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Water management is an important issue to be addressed to maintain the stable and efficient operation of a proton exchange membrane fuel cell (PEMFC). Gas purging is commonly performed to remove accumulated water in a PEMFC, especially in a dead-ended fuel cell system. A 3D dynamic model with a user-defined inlet boundary condition is proposed to study the effect of gas purging with different purge durations in an H2/O2 PEMFC. The results show that the performance immediately deteriorates and then recovers to the original level during gas purging. Purging has a significant effect on the flow and mass transfer in the flow channel, and it leads to efficient removal of water from the PEMFC. The voltage variation tendency is consistent with the water content of the membrane. Membrane dehydration is the main reason for the performance degradation. Notable variations could be observed with increments in the purge duration. Water in a PEMFC is more sensitive and responsive to changes of operating conditions than the reactants. In addition, the performance is significantly deteriorated at a ... Read More

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The hydrogen proton exchange membrane (PEM) fuel cell is a mature and widely used fuel cell technology widely used in automotive powertrains, distributed generation, and unmanned aircraft, and in the military in the future. As a beginning to this book, this chapter introduce the fundamentals, including the operation principle, PEM fuel cell structure, thermodynamics, electrochemical reaction kinetics, PEM fuel cell performance, and PEM fuel cell efficiency. Water and thermal management is a critical part of PEM fuel cell studies. Its main research areas can be summarized as a deeper understanding of transport phenomena in PEM fuel cells. It presents the optimal design of each component to control the internal transport process effectively to improve performance, reduce costs and enhance durability.

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The AEM layer content in a bipolar interface fuel cell enables the opportunity to regulate the influx rate of water into the porous layer.

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In this study, water removal is observed through a transparent fuel cell, and the relationships between it and the responses of voltage and impedance are analyzed. The water flows in the channel are accompanied by voltage soaring. For all studied cases, water flow appearances increase as GDL flooding is induced by supplying more vapor; for example, under a stoichiometry ratio of 2.0, the number of water flow appearances is 0, 3, and 25 for 1800 s as relative humidity increase to 30, 50, and 100%. The average voltage is calculated, and a positive relationship between it and the frequency of water flows is determined. The results reveal that frequent flooding-induced water removal could be one strategy to enhance fuel cell performance.

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Effective water management is particularly critical for fuel cells fed by hydrogen/oxygen. An ejector is an optimal device for the gas recirculation subsystem of a proton exchange membrane fuel cell (PEMFC) and is usually adopted for the auxiliary drainage of hydrogen/oxygen stacks. To explore the performance degradation of the fuel cells operating in dual ejector-based recirculation mode for both the anode and cathode, the dynamic characteristics of gas purging of the PEMFC was studied experimentally and the effects of the electrolyte and gas management strategy of the fuel cell on performance degradation were investigated in detail by using the measurement of polarization curves, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and scanning electron microscopy (SEM) images of membrane electrode assembly (MEA) cross sections. The results indicated that the fuel cell with Nafion 212 operating in the dual ejector-based recirculation mode has a better performance than that operating in the dead-ended mode, with total electrochemical surface area (ECSA) degradatio... Read More

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Fuel cells are not a new technology, but they are gaining in popularity and are being intensively developed. The article presents and characterizes various types of fuel cells that are currently of interest to research and development centers dealing with environmental protection issues. These include: alkaline fuel cell (AFC), phosphoric acid fuel cell (PAFC), solid oxide fuel cell (SOFC), molten carbonate fuel cell (MCFC), proton exchange membrane fuel cell (PEMFC), including direct methanol fuel cell (DMFC). The operating parameters of the previously mentioned fuel cells were compared. The principle of operation of a fuel cell was described. The growing interest in devices using hydrogen as a fuel also results from the development of Power to Gas technology (P2G). Furthermore, the article presents the potential directions of development and use of fuel cells in various fields and sectors of the economy. Fuel cells can be used in transport. The characteristic of motor vehicles fleet by fuel type in usage in the European Union was presented. The technical specification of commercial... Read More

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Proton exchange membrane fuel cells (PEMFCs) are promising power-generation sources for mobile, stationary, and emergency backup power applications. Proper water management within the cell is crucial for the optimum performance and durability of PEMFCs. Excessive water leads to the flooding of the cathode compartment, while dehydration of the membranes results in increasing resistive losses. Therefore, water management is critical to the successful implementation of PEMFCs. To optimize the water balance, various designs have been proposed and tested. These approaches include the use of more complex diffusion media and microporous layers, liquid water injection, wicking of liquid water, and the use of different flow-field pathways 1 . The latter two approaches seek to enable self-humidification of the PEMFCs system, thereby decreasing the cost and parasitic power losses of external components such as humidifiers. In this study, a porous hydrophilic bipolar plate with different pore structures were designed and characterized. Methods and compositions to produce fuel cell bipolar plates... Read More

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A passive regulation system for the water content has been developed and evaluated for a proton exchange membrane fuel cell. It is of particular relevance for micro-fuel cells, whose volume, weight and extra-consumption of fuel and power for subsidiary components must be kept to a minimum. This solution consists of a self-regulating humidity system implemented at the anode chamber that allows free water exchange with the environment through the surface of a gas-tight membrane. The micro-fuel cell, which is designed according to the patent WO2015025070A1, has been assembled and operated under completely passive conditions. The behavior of the anode humidity regulation system has been analyzed externally and in situ. The external part of the anode, where the humidity exchange with the environment takes place, has been isolated in a closed chamber and a hygrometer has been used to register the relative humidity in the zone near to the water exchange film. The results obtained from the operation of this innovative system are discussed in the light of the water permeation behavior of diff... Read More

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Abstract The presence of water in the flow field greatly affects the performance of PEM fuel cell. One of the problems is caused by the water imbalance in the PEM fuel cell. If the water content is too high it causes flooding in the PEM fuel cell stack. As a result, the distribution flow of raw materials (hydrogen and oxygen) flowing into the stack is blocked. Conversely, if it is too dry it will cause the membrane to crack. Both cases resulted in a decrease in the performance of the PEM fuel cell system. The method used for water management in the flow field of a bipolar plate flow Computating Fluids Dynamics (CFD) software. The results showed that the highest water content occurred in the spiral flow field at a flow rate of 4 x 10 -8 kg/s with a water content of 0.75 g/g. The lowest water content occurs in the multiple channel serpentine flow field at a flow rate of 4 x 10 -8 kg/s with the water content of 0.47 g/g. In this condition the performance of PEM fuel cell is relatively stable in the single channel serpentine flow field with a flow rate of 4 x 10-8 kg/s and a depth of 0.3... Read More

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