Mitigating Water Accumulation in Fuel Cells

As polymer electrolyte membrane (PEM) fuel cells progress toward widespread commercialization for automotive applications, achieving enhanced durability heavy-duty vehicle (HDV) use becomes a critical challenge. The urgency of this advancement arises from the increasing demand lightweight, material-efficient, and sustainable energy systems to support zero-emission transportation, where PEM present distinct advantages over traditional battery systems. Among technical hurdles, effective water management is paramount ensuring reliable prolonged operation cells, particularly under high-stress conditions characteristic HDV applications. electrode assembly (MEA), functional core cell, consists two electrodes (anode cathode) separated by Nafion-based ionomer sandwiched between gas diffusion layers (GDLs) on both sides. Key electrochemical processes, including hydrogen oxidation reaction (HOR) at anode oxygen reduction (ORR) cathode, produce as byproduct. To sustain performance prevent degradation, must be efficiently removed avoid accumulation flooding, which could otherwise compromise cell... Read More

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Method for preventing condensate buildup in fuel cell systems used in vehicles like utility vehicles. The method involves injecting dry compressed air from the vehicle's existing compressed air supply into the cathode flow path of the fuel cell system. This displaces any moisture, like condensate, in the air and cathode off-gas, preventing it from accumulating in components like expander stages, bearings, and condensate separators. The compressed air injection is done before starting or after stopping the fuel cell components to dry them out.

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Fuel cell vehicle cooling method that improves evaporative cooling efficiency using recovered condensed water. The method involves spraying condensed water from the fuel cell onto the radiator to cool it. The amount sprayed is initially set based on the fuel cell load. If recovery exceeds evaporation, the spray amount is reduced. If recovery is low, it is increased. This matches the spray to the evaporative efficiency based on recovery feedback. This prevents wasting water and maximizes evaporative cooling efficiency.

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Fuel cells, as one of the most promising alternatives to lithium-ion batteries for portable power systems, still face significant challenges. A critical issue is their substantial performance degradation under low-humidity conditions. To address this, researchers commonly add silica components. This study employs a control variable method systematically investigate impact four parametersgas stoichiometry, temperature, humidity, and contenton fuel cell performance. Initially, effects gas humidity on were examined. Subsequently, hydrophilic was incorporated into membrane electrode assembly (MEA) assess its potential improving in environments. Experimental results reveal that 100% humidification, addition had minimal performance, particularly at high temperatures where improved by only 2.5%. attributed increased water production elevated temperatures, whichwhen combined with silicas retention propertiesexacerbates flooding. However, when reduced 50%, incorporation significantly enhanced At resulted 126.2% improvement, demonstrating efficacy rational strategy

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Condensate water storage device for fuel cell systems in applications like construction vehicles where the condensate water discharge needs to be controlled to prevent contamination and accidents. The device has a storage container with a valve that can be selectively opened to discharge the condensate water. The valve is moved by a driving source outside the container. This allows controlling whether the condensate water is discharged or stays in the container. The valve can have seals and elastic members to prevent leaks. The container can also have overflow holes to prevent overfilling.

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Turbomachine for fuel cell systems with an expander wheel and an air bearing to support the rotor shaft. A flow generator is placed in the flow path between the expander wheel and the air bearing. It generates an air flow towards the expander wheel based on rotor shaft speed. This prevents water condensate from entering the air bearing. As the turbomachine speed increases, the flow generator pushes more air to the expander wheel to counteract the positive pressure there. This avoids water ingress into the bearing as it's already spinning fast enough to generate sufficient air flow.

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Abstract Polymer electrolyte fuel cells (PEFCs) face significant challenges during cold starts, where water phase transitions affect critically cell performance. While previous studies have primarily focused on ice formation and melting behavior, the impact of condensation after breaking through freezing point remains insufficiently understood. In this study, we apply operando synchrotron X-ray computed tomography to visualize transient behavior in a PEFC under three different relative humidity (RH) conditions heating/cooling cycle simulating real-world cold-start conditions. The results revealed localized flooding hysteresis phase. A quantitative layer-by-layer analysis shows that accumulation each component layer strongly depends both RH thermal process. Moderate promote efficient vapor-phase transport minimize while avoiding membrane dehydration. These findings highlight as key factor influencing performance provide new insights into management for more robust strategies toward next-generation systems.

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Cooling system for fuel cells in vehicles like aircraft that uses water droplets sprayed into the air cooling the fuel cell to absorb heat. The water droplets evaporate, absorbing more heat than air alone. After the fuel cell, a condenser removes moisture from the air and returns it to the sprayer. This provides more effective cooling with less airflow. It also uses a PCM coolant in the fuel cell channels that evaporates partway to further absorb heat. This allows using smaller cooling components.

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Water extraction system for a fuel cell stack to extract water from the exhaust flow and provide it back to the fuel cell stack to maintain hydration levels. The system uses a condenser to cool the exhaust, an extractor to remove water, a turbine to extract energy from the dehumidified exhaust, and a reheater to transfer heat from the turbine exhaust back to the dehumidified exhaust. This allows extracting water, extracting energy, and transferring heat in a closed loop.

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<title>Abstract</title> In a Proton Exchange Membrane Fuel Cell (PEMFC), the geometry of flow channels plays critical role in mass transport, electrochemical current distribution, and water management. The objective this study is to investigate effect obstacle aspect ratio (AR) cathode channel on cell performance under various operating conditions (temperature 333363 K, pressure 14 atm, anode/cathode relative humidity 0100%). To end, three-dimensional numerical model was developed, governing equations for species energy, electric were solved using computational fluid dynamics (CFD) with finite-volume method. geometric parameters included AR = 0 1 rectangular obstacles both anode channels, boundary corresponding temperature, pressure, simulated independently. results showed that intermediate-sized 0.250.50 significantly enhance oxygen transport reduce concentration losses; example, at mid-range temperatures (343353 K) pressures 12 power density increased by more than 20%. Specifically, 343 K 0.75, rose from 0.3769 0.5289 W/cm. At higher (34 atm), however, be... Read More

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A condensate water drain control system for fuel cells that can accurately drain condensate water from the fuel cell stack even when the water level sensor fails. The system estimates the fuel cell's chemical reaction amount and opens the drain valve based on that. When the valve is open, it closes it again based on the fuel supply state to prevent over-draining. This allows condensate drainage without relying on the sensor.

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&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;This study presents a novel biomimetic flow-field concept that integrates triply periodic minimal surface (TPMS) porous architectures with hierarchical leaf-vein-inspired distribution zone, fabricated through 3D printing. By mimicking natural transport systems, the proposed design enhances oxygen delivery and water removal in proton exchange membrane fuel cells (PEMFCs). The results showed &lt;b&gt;&lt;i&gt;I&lt;/i&gt;&lt;/b&gt;-FF &lt;b&gt;&lt;i&gt;G&lt;/i&gt;&lt;/b&gt;-FF significantly improved mass management compared to conventional CPFF. integrated &lt;b&gt;&lt;i&gt;I&lt;/i&gt;&lt;/b&gt;-FF-LDZ achieves up 32% improvement power density at 1.85 &lt;b&gt;&lt;i&gt;A&lt;/i&gt;&lt;/b&gt;/&lt;b&gt;&lt;i&gt;cm&lt;/i&gt;&lt;/b&gt;&lt;sup&gt;&lt;b&gt;2&lt;/b&gt;&lt;/sup&gt;@0.4 V delays onset of losses. also reveals optimizing volume fraction &lt;b&gt;&lt;i&gt;V&lt;/i&gt;&lt;/b&gt;&lt;sub&gt;&lt;b&gt;&lt;i&gt;f&lt;/i&gt;&lt;/b&gt;&lt;/sub&gt; affects gas penetration, lower (30%) improving performance mass-limited r... Read More

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A fuel cell exhaust system that efficiently separates water from the exhaust gas without additional flow obstructions. The system has a condenser to condense water vapor from the exhaust and a separator with a curved channel surrounded by a chamber. The chamber collects condensed water as it flows through the channel due to centrifugal and gravitational forces. This eliminates the need for further water separation measures in the fuel cell exhaust system.

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This study investigates the effects of anode and cathode inlet flow rates () on power performance bipolar plates in a polymer electrolyte membrane fuel cell (PEMFC). The primary objective is to derive optimal rate conditions by comparatively analyzing concentration loss IV curve crossover phenomena at anode, thereby establishing that prevent reactant depletion water flooding. A single-cell computational model was constructed assembling commercial plate with gas diffusion layer (GDL), catalyst (CL), proton exchange (PEM). simulates current density generated electrochemical oxidation-reduction reactions. Hydrogen oxygen were supplied 1:3 ratio under five proportional conditions: hydrogen (mH2 = 0.763.77 LPM) (mO2 2.3911.94 LPM). ButlerVolmer equation employed voltage drop due overpotential, while numerical simulations incorporated contact resistivity, surface permeability, porous media properties. Simulation results demonstrated 24.40% increase when raising mH2 from 2.26 3.02 LPM mO2 7.17 9.56 LPM. Further increases 3.77 11.94 yielded 10.20% improvement, indicati... Read More

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Closed loop cooling system for fuel cell stacks that enables efficient water management and cooling without the need for external water injection or exchange columns. The system recycles water from the fuel cell exhaust streams to cool the stack and maintain hydration. It uses a controller to automatically manage the water injection and removal based on stack conditions. This allows optimized water management for performance and reduces contamination compared to external water injection. The controller calculates the water balance and adjusts injection based on stack water generation, stack temperature, and cooling needs.

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Real-time monitoring of water flooding in fuel cells using optical imaging and machine learning to predict cathode pressure drops. The system involves capturing high-speed images of the cathode backing layer during operation and using computer vision techniques to detect water droplets as anomalous pixels surrounded by humidity. A mask is applied to ignore background noise and separate water droplets inside each channel. Machine learning models are trained to predict cathode pressure using the extracted water features. This allows real-time monitoring of water flooding without extensive resources and equipment, as well as estimating the effect of water flooding on oxygen pressure.

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Abstract The porosity of the Gas Diffusion Layer (GDL) has an impact on mass transport within Proton Exchange Membrane Fuel Cells (PEMFC), thus affecting output performance cells. In this research, a three-dimensional (3D) geometric model PEMFC with two-channel serpentine flow field at anode and seven-channel sinusoidal cathode was created. also considered water mechanisms in electrolyte phase change between surrounding pores. Simulations were conducted for GDL porosities 50%, 40%, 30%, 20%, 10%, respectively. results show that medium to high current density range, significantly affects cell performance. As increases, uniformity distribution membrane is enhanced. Under given voltage condition, increasing leads higher power output. Compared 50% peak 40% greater.

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Overhumidification is a critical challenge to the performance and durability of polymer electrolyte fuel cells (PEFCs). This review evaluates current methods for detecting quantifying overhumidification, focusing on simulation, imaging, sensor technologies. Each method assessed based five key criteria: precision, sensitivity, realtime capability, interpretation complexity, validation strength. Physically grounded modeling approaches such as computational fluid dynamics lattice Boltzmann offer high accuracy but are computationally demanding. Imaging techniques, including neutron imaging magnetic resonance provide valuable insight face limitations regarding scalability application. Sensor technologies, from commercial sensors artificial intelligenceenhanced nanostructured platforms, enable monitoring require improved robustness under operando conditions. By comparing these techniques individually collectively, this identifies promising hybrid strategies outlines research priorities achieving intelligent, water management in PEFCs.

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Abstract The flow field in a proton exchange membrane fuel cell is essential for efficiently managing water removal, especially at high current densities. This study designs that facilitates removal and presents considerations its implementation. A 3-path serpentine channel has been adopted as the reference model. When contact resistance not considered, performance of check-pattern superior under all voltage conditions, with maximum increase 5.1 %. considering resistance, similar most conditions; however, densities, checked pattern exhibits performance, improving by 5 to 7.2 larger rib area hinders but reduces resistance. Therefore, should be designed both together.

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The air-cooled fuel cell is a promising energy conversion device. However, the characteristics of forced convection often rapidly expel water from gas diffusion layer (GDL) into flow field, which reduces humidity membrane electrode assembly (MEA). Under low-humidity conditions, proton conductivity exchange (PEM) decreases, thereby impairing performance and durability cell. Inspired by tortuous transport pathways in maze model, we designed GDL with maze-like structure (M-GDL) to extend path, increasing internal We evaporation test verify loss resistance GDL. M-GDL exhibits remarkable loss, rate 0.35 mg min-1 cm-2, significantly lower than 0.79 cm-2 observed for commercial This extended retention capability leads notable increase cell, peak power density 0.77 W more double that GDL, where only 0.4 cm-2. work presents strategy mitigate issue low cells.

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