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This study investigates key performance determinants of air-cooled open-cathode PEMFCs, focusing on cathode channel design, assembly preload, and stack configuration. The anisotropic point structure channel design was found to enhance cell performance, with the staggered arrangement mode outperforming the parallel mode. Optimal bolt torque varies with bipolar plate dimensions, following a linear relationship: a 5 mm reduction in width increases the optimal torque by 2 N·m. An innovative double-stack configuration with a fan was introduced, with the optimal setup being a combination of a larger and smaller stack for maximum performance. These findings offer practical guidance for fuel cell design and assembly, advancing the viability of air-cooled PEMFCs. • The anisotropic point flow shows promise for cathode application in air-cooled. • A reduction of 5 mm with an approximate 2 N·m increase in the optimal preload. • The double stack with a fan has demonstrated feasibility and efficacy. • The larger stack for draw and a smaller for blowing, yielding superior performance. [ABSTRACT FROM AUTHOR]

Currently, the prediction of proton exchange membrane fuel cell (PEMFC) performance is mainly focused on short- and medium-term prediction. Accurate long-term prediction can provide ample time for developing reliable maintenance strategies, which is more conducive to extending the lifespan of PEMFC. Therefore, a long-term prediction model based on wavelet analysis with dynamic time warping and linear enhanced neural network (W-LENN) is proposed. In view of the influence of external environment on PEMFC, wavelet analysis with dynamic time warping is used to obtain global and detailed information of performance while avoiding excessive signal decomposition. To more strongly map the non-linear and linear relationships between the control parameters and the health indicator, linear enhanced neural network is built to predict each sub-waveform. In addition, the durability test under complex dynamic cycle condition is carried out. The effectiveness and superiority of W-LENN were verified in different conditions. The results show that under different conditions, the longer the prediction length, the more pronounced the advantages of W-LENN are compared to other methods. Among them, when the 500H data is used for training under complex dynamic cycle conditions, the RMSE and MAE predicted by W-LENN for the test set are reduced by 80.32% and 83.44% compared with the most basic model. • The voltage data are analyzed by wavelet decomposition with dynamic time warping. • The linear enhanced neural network is built to predict the voltage component. • The durability test under complex dynamic cycle condition is carried out. • The proposed method can be used effectively for long-term prediction. • The proposed method is applied to 3 conditions and its superiority is verified. [ABSTRACT FROM AUTHOR]

In this paper, the latest progress and multi-field application prospect of hydrogen fuel cell technology are reviewed, the basic principle and core structure of hydrogen fuel cell are deeply analyzed, and the development trends of proton exchange membrane fuel cell (PEMFC) and alkaline fuel cell (AFC) are emphatically introduced. It is necessary to focus on developing new polymer materials & structures for PEMs/AEMs, enhancing stability & conductivity. Explore non-Pt catalysts & green preparation methods. Optimize microporous layers for cost & performance. Integrate AI for intelligent water management, ensuring safety & adaptability across diverse environments. [Display omitted] • Summarizing the comparison of PEMFC and AFC in automotive applications. • Analyzing future research direction of important components in hydrogen fuel cells. • Introducing emerging technology to hydrogen fuel cell research. • Analyzing research results of hydrothermal management system in hydrogen fuel cells. [ABSTRACT FROM AUTHOR]

Active thermal management strategies are critical for optimizing fuel cell performance by regulating stack temperature in response to output power variations. However, existing approaches often fail to adequately consider the impact of multi-source perturbations, such as gas supply perturbations or voltage distribution heterogeneity. To bridge this gap, we propose a nonlinear autoregressive exogenous network surrogate model to simulate fuel cell voltage distribution. This model is integrated into an advanced online thermal management control system. The proposed strategy employs an artificial bee colony optimization algorithm and a tube-based robust model predictive control strategy with relaxation factors. It enables real-time regulation of coolant outlet and inlet temperatures in response to variations in load current, reactant gas flow rate and pressure, and voltage distribution characteristics. Experimental results demonstrate that at a current density of 1.0 A/cm2, the strategy increased the average cell voltage by 6.1 mV, reduced the voltage extreme difference by 40.3%, and lowered the voltage standard deviation by 54.9%. The active thermal management strategy significantly enhances the performance of fuel cells under multi-source perturbations. [Display omitted] • Both thermal management system internal and external perturbations are considered. • Voltage with stack temperature and stack temperature difference is modeled. • A constraint relaxation tube-RMPC is designed for fuel cell steady-state processes. • A NARX neural network is constructed to predict fuel cell performance in real time. • The strategy improves both stack performance and voltage consistency. [ABSTRACT FROM AUTHOR]

Accurate economic assessment of proton exchange membrane fuel cell (PEMFC) vehicles is essential for optimizing control strategies in the PEMFC industry, which is largely driven by the need to reduce costs. Traditional data-driven approaches have focused on reconstructing typical driving cycles from real-world speed data, often overlooking the intensity and acceleration of these cycles. These factors are crucial for water and heat management in PEMFCs and can lead to inaccurate estimates of hydrogen consumption. This paper introduces a novel algorithm for typical driving cycles reconstruction based on real-world data, named the improved two-dimensional Markov Chain Monte Carlo (2D MCMC) approach using Metropolis-Hastings (M − H) sampling. The approach innovatively encodes the integration of real-time vehicle speed and acceleration sequences into a hierarchical 2D state transition probability matrix. To optimise both accuracy and computation time, the M − H based sampler is newly introduced to generate typical driving cycle without the computational burden of multiplying large matrices. Moreover, by integrating the agglomerative nesting (AGNES) alongside a comprehensive evaluation system that incorporates simulation and bench testing, the proposed approach effectively weights real-world route conditions in the economic assessment. Case studies involving 10 PEMFC hybrid buses in Shanghai, China, validate the effectiveness and robustness of the proposed method. Comparative analyses show that the relative errors in hydrogen consumption per 100 km between the reconstructed and real-world driving cycles are within 1.20–3.01% for all ten buses in Shanghai, with computation times reduced by up to 12.60% compared to the existing methods. [Display omitted] • Introduces a novel 2D MCMC for PEMFC vehicle driving cycle reconstruction. • Enhances accuracy and speed in hydrogen consumption assessment using Metropolis-Hastings (M − H) sampling. • Effectively incorporates real-world conditions using AGNES. • Demonstrates effectiveness and robustness of the proposed approach on ten PEMFC buses in Shanghai, China. [ABSTRACT FROM AUTHOR]

[Display omitted] • Basic principles and frontier progress of proton exchange membrane fuel cell catalysts are briefly introduced. • Low Pt content catalyst characteristics are analyzed. • Ordered intermetallic Pt-M alloy synthesis concept is described and interpreted. • Difficulty and improvement directions about ordered PtCo 3 are discussed. This review is devoted to the potential advantages of ordered alloy catalysts in proton exchange membrane fuel cells (PEMFCs), specifically focusing on the development of the low Pt content, high activity, and durability ordered PtCo 3 catalyst. Due to the sluggish oxygen reduction reaction (ORR) kinetics and poor durability, the overall performance of the fuel cell is affected, and its application and promotion are limited. To address this issue, researchers have explored various synthetic strategies, such as element doping, morphology adjusting, structure controlling, ordering and support/metal interaction enhancement. This article extensively discussed the Pt related ORR catalysts and follows an in-depth analysis of ordered PtCo 3. The introduction briefly discusses the direction of development of fuel cell catalysts and frontier progress, including theoretical mechanism, practical preparation, and Pt-containing electrode structures, etc. The subsequent chapter focuses on the Pt-Co catalyst, the evolution process of Pt alloy to Pt-Co alloy and the improvement scheme are introduced. The next chapter describes the properties of PtCo 3. Although the ordered PtCo 3 catalyst has a wide range of applicability due to low cost and high activity catalyst. However, besides the common agglomeration and sintering problems of Pt-Co alloy, its commercial application still faces unique problems of oversized crystal size, phase segregation, ordering transformation and transition metal dissolution. Therefore, in Chapter 4, this overview provides some possible improvement methods for three specific functions: crystal refinement, enhancing the effect of support and active substances, and anti-dissolution. [ABSTRACT FROM AUTHOR]

This paper focuses on the determinants of establishing dominant hydrogen fuel cell technology designs in the maritime industry in Western Europe. By systematically studying the battle between the Solid Oxide Fuel Cell and the Proton Exchange Membrane Fuel Cell, utilizing the best-worst method it arrives at importance for factors for design dominance. It appears that 'fuel cell costs' is the most important factor: it received a global average weight of 0.18. This is the first time that factors for design dominance are studied in the maritime industry and the paper offers novel empirical material from a distinct sector. It also provides a first indication that the Solid Oxide Fuel Cell will have the highest chance to become the dominant design although the Proton Exchange Membrane Fuel cell is a close follower. The paper discusses contributions, implications, and future research recommendations for the literature on dominant designs. • This paper studies factors for hydrogen fuel cell technology design dominance. • Two technologies are compared in a systematic way using the best worst method. • Fuel Cell Costs was seen as most important receiving a global average weight of 0.18. • Solid Oxide Fuel Cell has the highest chance to dominate closely followed by PEMFC. [ABSTRACT FROM AUTHOR]

In this study, we focus on modeling the dynamic system of a fuel cell hybrid vehicle, particularly the stack, to enhance hydrogen utilization efficiency through an adapted energy management control strategy. The fuel cell system is modeled for each balance of plant (BOP) component. In the modeling of the stack, it was designed to enable the calculation of water behavior inside gas diffusion layer. After modeling this vehicle system, we tested three different driving strategies across five driving cycles: HWFET, FTP-75, UDDS, NEDC, and WLTP. The strategies explored were constant power, baseline, and target State of Charge (SOC) change. Our findings reveal that the target SOC change strategy resulted in the lowest hydrogen consumption, with minimal variation in battery SOC at the beginning and end of the drive. Specifically, this strategy led to a hydrogen consumption reduction of approximately 24% in low-load conditions (FTP-75, UDDS, NEDC) and 10% in high-load conditions (HWFET, WLTP). • Dynamic model of fuel cell system is applied for accurate simulation of fuel cell vehicle system. • New target SOC change method proposed and compared with other EMS methods. • Target SOC method minimizes hydrogen use across simulations in five drive cycles. [ABSTRACT FROM AUTHOR]

In order to increase the overall efficiency of the Polymer Electrolyte Membrane (PEM) fuel cell system the recirculation of excess hydrogen from the fuel cell outlet to the inlet can be conducted by a passive hydrogen ejector instead of an electric hydrogen pump. The disadvantage of a hydrogen ejector with a fixed layout is that it does not cover the necessary range of the fuel cell operating conditions from low to high power. Therefore, in this study a new approach for thoroughly analyzing the influence of variable geometric parameters on the recirculation performance of the passive hydrogen ejector is investigated by Computational Fluid Dynamics (CFD) simulations. Based on a sensitivity analysis the nozzle radius has been identified as geometric parameters which has the largest effect on the mass flow and mass flow ratio. A moving needle concept has been selected as most suitable to vary the nozzle cross section. Compared to a passive recirculation unit with a fixed ejector geometry for a fuel cell operation limited to 100 kW the needle concept allows an operation from 17 kW to 100 kW of fuel cell power. An additional optimization with a two-step needle can further reduce the sensitivity of the fuel cell pressure drop from 50 mbar to 70 mbar on the necessary mass flow at low fuel cell power. System simulations of the hydrogen ejector confirm that the variable recirculation unit can be operated also under dynamic operation of the fuel cell system by maintaining the necessary mass flow and mass flow ratio. • A concept for a variable passive hydrogen recirculation unit is developed. • Influence of ejector geometries on recirculation characteristics is evaluated. • Variable recirculation unit maintains required stoichiometry ratios. [ABSTRACT FROM AUTHOR]

This study investigated the development of chopped carbon fiber (CCF)‐reinforced epoxy (EP)/graphite (G) composite bipolar plates (BPs) using a one‐step compression molding process. The primary objective was to fabricate CCF‐reinforced EP/G BPs to enhance their electrical conductivity performance by evaluating the electrical conductivity and compactness of the plate among expanded graphite (EG), carbon black (CB) Vulcan, a combination of EG and CB Vulcan, and CB Ensaco. The results indicated that the EG exhibited the highest electrical conductivity of 9.3 S cm−1 and compactness due to the low surface area. Consequently, CCF‐reinforced EP/G/EG was selected for further optimization using response surface methodology (RSM) to analyze the parameters of EG composition, CCF composition, and temperature for optimizing electrical conductivity and porosity. The optimum conductivity and porosity of the CCF‐reinforced EP/G/EG reached 22.7 S cm−1 and 9.84% with EG composition, CCF composition, and temperature of 7.56 wt.%, 6.63 wt.%, and 186°C, respectively. After optimization, EP/G/EG was connected to a circuit to light up a bulb. It showed a substantial improvement in illumination compared with the samples before optimization. Therefore, the use of CCF‐reinforced EP/G/EG with one‐step compression molding has proven highly successful for converting energy in renewable energy applications, showcasing exceptional performance. [ABSTRACT FROM AUTHOR]

This research aims to assess the integration of different fuel cell (FC) options with battery and waste heat recovery systems through a mathematical modelling process to determine the most feasible retrofit solutions for a marine electricity generation plant. This paper distinguishes itself from existing literature by incorporating future cost projection scenarios involving variables such as carbon tax, fuel, and equipment prices. It assesses the environmental impact by including upstream emissions integrated with the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII) calculations. Real-time data have been collected from a Kamsarmax vessel to build a hybrid marine power distribution plant model for simulating six system designs. A Multi-Criteria Decision Making (MCDM) methodology ranks the scenarios depending on environmental benefits, economic performance, and system space requirements. The findings demonstrate that the hybrid configurations, including solid oxide (SOFC) and proton exchange (PEMFC) FCs, achieve a deduction in equivalent CO2 of the plant up to 91.79% and decrease the EEXI and the average CII by 10.24% and 6.53%, respectively. Although SOFC-included configurations show slightly better economic performance and require less fuel capacity, the overall performance of PEMFC designs are ranked higher in MCDM analysis due to the higher power density. [ABSTRACT FROM AUTHOR]

Purging is widely used in controlling water content during cold starts. High-frequency resistance (HFR) is one of the main methods used to characterize the water state in membrane electrode assemblies (MEA). However, it is difficult to accurately determine the water content inside the fuel cell at shutdown using the HFR alone. Thus, in this study, a method for characterizing the water state of MEA based on the distribution of relaxation times polarization resistance was established. Based on the experiment, the water content variation in each component during shutdown purge was analyzed. Finally, the influence of operating parameters during shutdown purge on the water content was analyzed, showing that purge efficiency in Stage 1 increased with the purge flow rate. While in Stage 2, it was influenced by the coupled effects of temperature and flow rate. Moreover, low relative humidity significantly improved the purge efficiency in Stages 1 and 2. • A method was devised to identify water state in MEA during shutdown purge with load. • Changes in water content of components during shutdown purge were tracked with EIS. • Water state of components during purging process forms three distinct stages. • Flow rates, temperatures, loading currents, and RH affect water state changes. [ABSTRACT FROM AUTHOR]

During an aging test of a high temperature proton exchange membrane fuel cell (HT-PEMFC) without exhaust pressure control loop, the anode and cathode pressures are dependent on variations in gas flow and atmospheric pressure. The voltage degradation rate is then impacted by atmospheric pressure variations. To extract the aging rate independently of the pressure, a possible solution is to estimate the voltage variation at a given pressure change. In this work, this voltage/pressure sensitivity was estimated in post-processing, by fitting regression planes (on measured voltage data) in the three dimensions: voltage, pressure, and time. It was applied on an aging test of 2753 h at 160 °C, at ambient pressure and at different constant currents (0.2, 0.4, and 0.6 A/cm2) which was carried out on an Advent Technologies Inc. PBI MEA of 45 cm2 active surface. The impact of varying atmospheric pressure on the calculation of degradation rates is then discussed and compared with another method developed in a previous work. It was found that a variation of 6 mV (2.4 % of initial voltage) at 1 A/cm2 during an aging test can be attributed to pressure variation alone, and not to cell degradation. Furthermore, it was observed that the voltage/pressure sensitivity is different depending on the period analyzed, at identical operating conditions (which would indicate that the dependence on pressure varies during aging). Indeed, at 0.2 A/cm2, the voltage response to a variation in pressure was quantified at approximately 50 μV/mbar and 80 μV/mbar at the start and end of life respectively. This method could therefore be used as an on-line diagnostic tool to monitor the fuel cell state of health. [Display omitted] • Aging test of a high temperature proton exchange membrane fuel cell for 2753 h. • Model of the impact of pressure and time on cell voltage. • Obtaining coefficients of the voltage variation against pressure and time. • Degradation rate can significantly be impacted by pressure variations only. • Method for post processing aging tests to correct the voltages against pressure. [ABSTRACT FROM AUTHOR]

Increasing demand for clean energy power generation is a direct result of the rapid depletion of fossil fuel reserves, the volatility of fossil commodity prices, and the environmental damage caused by burning fossil fuels. Fuel cell vehicles, portable power supplies, stationary power stations, and submarines are just some of the applications where proton exchange membrane (PEM) fuel cells are a prominent technology for power generation. PEM fuel cells have several advantages over conventional power sources, including a higher power density, lower emissions, a lower operating temperature, higher efficiency, noiseless operation, ease of design, and operation. The catalyst layer of the membrane electrode assembly is discussed in this paper as a vital part of the proton exchange membrane fuel cell. Along with that, the platinum (Pt)-based catalyst, carbon support, and nafion ionomer found in the catalyst layer often degrade. Catalyst growth, agglomeration, Pt loss, migration, active site contamination, and other microscopic processes are all considered in the degradation process. Employing experimental and numerical research with a focus on enhancing the material properties was suggested as a possible solution to understanding the problem of catalyst layer degradation. Ultimately, this review aims to prevent catalyst layer degradation and lower the high costs associated with replacing catalysts in proton exchange membrane fuel cells through the recommendations provided in this study. [ABSTRACT FROM AUTHOR]

Proton Exchange Membrane Fuel Cells (PEMFCs) are widely regarded as promising clean energy technologies due to their high energy conversion efficiency, low environmental impact, and versatile application potential in transportation, stationary power, and portable devices. Central to the operation and performance of PEMFCs are advancements in materials and manufacturing processes that directly influence their efficiency, durability, and scalability. This review provides a comprehensive overview of recent progress in these areas, emphasizing the critical role of membrane electrode assembly (MEA) technology and its constituent components, including catalyst layers, membranes, and gas diffusion layers (GDLs). The MEA, as the heart of PEMFCs, has seen significant innovations in its structure and manufacturing methodologies to ensure optimal performance and durability. At the material level, catalyst layer advancements, including the development of platinum-group metal catalysts and cost-effective non-precious alternatives, have focused on improving catalytic activity, durability, and mass transport. Similarly, the evolution of membranes, particularly advancements in perfluorosulfonic acid membranes and alternative hydrocarbon-based or composite materials, has addressed challenges related to proton conductivity, mechanical stability, and operation under harsh conditions such as low humidity or high temperature. Additionally, innovations in gas diffusion layers have optimized their porosity, hydrophobicity, and structural properties, ensuring efficient reactant and product transport within the cell. By examining these interrelated aspects of PEMFC development, this review aims to provide a holistic understanding of the state of the art in PEMFC materials and manufacturing technologies, offering insights for future research and the practical implementation of high-performance fuel cells. [ABSTRACT FROM AUTHOR]

Proton exchange membrane electrolyzers are an attractive technology for hydrogen production due to their high efficiency, low maintenance cost, and scalability. To receive these benefits, however, electrolyzers require high power reliability and have relatively high demand. Due to their intermittent nature, integrating renewable energy sources like solar and wind has traditionally resulted in a supply too sporadic to consistently power a proton exchange membrane electrolyzer. This study develops an electrolyzer model operating with renewable energy sources at a highly instrumented university site. The simulation uses dynamic models of photovoltaic solar and wind systems to develop models capable of responding to changing climatic and seasonal conditions. The aim therefore is to observe the feasibility of operating a proton exchange membrane system fuel cell year-round at optimal efficiency. To address the problem of feasibility with dynamic renewable generation, a case study demonstrates the proposed energy management system. A site with a river onsite is chosen to ensure sufficient wind resources. Aside from assessing the feasibility of pairing renewable generation with proton exchange membrane systems, this project shows a reduction in the intermittency plaguing previous designs. Finally, the study quantifies the performance and effectiveness of the PEM energy management system design. Overall, this study highlights the potential of proton exchange membrane electrolysis as a critical technology for sustainable hydrogen production and the importance of modeling and simulation techniques in achieving its full potential. [ABSTRACT FROM AUTHOR]

Fuel cells contribute to decentralized and individually controllable energy supply. The low-temperature polymer electrolyte membrane fuel cell is ideal for both stationary and mobile use due to its low operating temperatures and superiority in discontinuous operation. Thermoplastics can be used as materials for bipolar halfplates, which have the advantage of low-cost manufacturing processes, as the components do not require cost-intensive post-processing due to their excellent corrosion resistance and electrical contacting. But the environmental conditions in operation pose a great challenge to the materials to be used: permanent humidity and sulphuric acid environment at 85°C, high required electrical conductivity and hydrogen impermeability. In order to demonstrate the potential of bio-based materials, adhesives for both sealing and conductive bonding of all joints within a fully bonded fuel cell are being developed and tested in an ongoing project. The epoxy resin systems developed can be both, one and two-component, and have different proportions of sustainable carbon. In addition, the fuel cell components, also consist of sustainable raw materials, so that bonding surfaces also pose a challenge. Results on the lap shear strength of the developed adhesives as well as on the durability of the adhesives under fuel cell environment are presented. Initial functional tests on bipolar plates bonded with proportionally bio-based raw materials show a functionality comparable to that of petroleum-based raw materials for epoxy adhesives. [ABSTRACT FROM AUTHOR]

The metal bipolar plate is a critical component of the hydrogen fuel cell stack used in proton exchange membrane fuel cells. Bipolar plates must have high accuracy micro-channels with a high aspect ratio (AR) between the channel depth and the half periodic width to achieve optimal cell performance. Conventional forming methods, such as micro-stamping, hydroforming, and rubber pad forming, cannot achieve these high ARs given that in these processes, material deformation is dominated by stretch deformation. In micro-roll forming the major deformation mode is bending, and this enables production of channels with higher ARs than is currently possible. However, micro-roll forming uses multiple sets of forming roll stands to form the part and this leads to technological challenges related to tool alignment and roll tool precision that must be overcome before widespread application can be achieved. This study presents a new methodology to achieve tight tool tolerances when producing micro-roll tooling by utilizing wire-EDM and micro-turning techniques. This is combined with a new micro-roll former design that enables high-precision tool alignment across multiple roll stations. Proof of concept is provided through micro-roll forming trials performed on ultra-thin titanium sheets that show that the proposed technology can achieve tight dimensional tolerances in the sub-millimeter scale that suits bipolar plate applications. [ABSTRACT FROM AUTHOR]

The flow distribution issue is of significance to the fuel cell stack performance and durability, which herein is studied from a theoretical and practical level. The manifold flow fundamentals are clarified and the pressure‐reconstruction‐based principle to regulate flow distribution is revealed. The prerequisite and corequisite lie in the ratio of pressure drop between headers and the entire manifold, and the pressure recovery in the inlet header. Accordingly, a step‐by‐step manifold design methodology is proposed and further quantified by detailed and organized simulations. A desirable effect on flow uniformity is validated in large‐scale stacks consisting of 300 and 400 cells, and the values of flow uniformity index represented by coefficient of variation (CV) are 3.32% and 2.95%, respectively. Moreover, a novel wedge‐shaped layout of the intake header is proposed for further optimization. The corresponding CV values have notably declined to 1.36% and 1.29%, nearly 60% lower than the conventional rectangular counterparts. [ABSTRACT FROM AUTHOR]

Hydrogen-based electric vehicles such as Fuel Cell Electric Vehicles (FCHEVs) play an important role in producing zero carbon emissions and in reducing the pressure from the fuel economy crisis, simultaneously. This paper aims to address the energy management design for various performance metrics, such as power tracking and system accuracy, fuel cell lifetime, battery lifetime, and reduction of transient and peak current on Polymer Electrolyte Membrane Fuel Cell (PEMFC) and Li-ion batteries. The proposed algorithm includes a combination of reinforcement learning algorithms in low-level control loops and high-level supervisory control based on fuzzy logic load sharing, which is implemented in the system under consideration. More specifically, this research paper establishes a power system model with three DC-DC converters, which includes a hierarchical energy management framework employed in a two-layer control strategy. Three loop control strategies for hybrid electric vehicles based on reinforcement learning are designed in the low-level layer control strategy. The Deep Deterministic Policy Gradient with Twin Delayed (DDPG TD3) is used with a network. Three DRL controllers are designed using the hierarchical energy optimization control architecture. The comparative results between the two strategies, Deep Reinforcement Learning and Fuzzy logic supervisory control (DRL-F) and Super-Twisting algorithm and Fuzzy logic supervisory control (STW-F) under the EUDC driving cycle indicate that the proposed model DRL-F can ensure the Root Mean Square Error (RMSE) reduction for 21.05% compared to the STW-F and the Mean Error reduction for 8.31% compared to the STW-F method. The results demonstrate a more robust, accurate and precise system alongside uncertainties and disturbances in the Energy Management System (EMS) of FCHEV based on an advanced learning method. [ABSTRACT FROM AUTHOR]

The cathode catalyst layer (CCL) provides the core site for the electrochemical reactions that occur in the proton exchange membrane fuel cell (PEMFC). Its composition directly determines the electrochemical and mass transfer performance of the fuel cell. Current experimental and modeling methodologies still have shortcomings in the comprehensive optimization of CCL performance. Therefore, this work proposes a machine learning framework combining a data-driven surrogate model and multi-objective optimization to effectively evaluate the influence of CCL compositions on three novel performance indexes, including voltage (V cell), average value of CCL oxygen concentration (C O 2 ), and water saturation (CCL sat). Firstly, CCL agglomerate model is integrated with the multi-physics PEMFC model to achieve an accurate characterization of performance. Numerical simulations provide a reliable database for training the surrogate model based on back propagation neural network (BPNN). Subsequently, the surrogate model is integrated with non-dominated sorting genetic algorithm-Ⅱ (NSGA-II) to expedite the assessment of fitness value for optimizing three performance indexes. Finally, the optimal CCL composition scheme located on the Pareto frontier is prioritized through the technique for order preference by similarity to an ideal solution (TOPSIS). The results show that the decision-optimal model demonstrates varying degrees of improvement compared to the base model, with a 6.17% improvement in V cell , increases of 5.84% in C O 2 , and reductions of 3.77% in CCL sat at 1 A cm−2. Therefore, a novel integrated optimization framework considering multi-factors and multi-objectives proposed in this study is of great significance in seeking the optimal CCL composition parameters and ultimately enhancing the comprehensive performance of PEMFC to accelerate its commercial application. • Voltage, oxygen concentration, and water saturation are proposed as performance indexes. • The comprehensive PEMFC model is validated by experimental data. • A novel integrated optimization framework for CCL is proposed. • Optimal model demonstrates remarkable improvement and credibility. • An appropriate trade-off between CCL electrochemical and mass transfer performance is revealed. [ABSTRACT FROM AUTHOR]

High-temperature proton exchange membrane fuel cells (HT-PEMFCs) offer solutions to challenges intrinsic to low-temperature PEMFCs, such as complex water management, fuel inflexibility, and thermal integration. However, they are hindered by phosphoric acid (PA) leaching and catalyst migration, which destabilize the critical three-phase interface within the membrane electrode assembly (MEA). This study presents an innovative approach to enhance HT-PEMFC performance through membrane modification using picosecond laser scribing, which optimises the three-phase interface by forming a graphene-like structure that mitigates PA leaching. Our results demonstrate that laser-induced modification of PA-doped membranes, particularly on the cathode side, significantly enhances the performance and durability of HT-PEMFCs, achieving a peak power density of 817.2 mW cm⁻² after accelerated stress testing, representing a notable 58.2% increase compared to untreated membranes. Furthermore, a comprehensive three-dimensional multi-physics model, based on X-ray micro-computed tomography data, was employed to visualise and quantify the impact of this laser treatment on the dynamic electrochemical processes within the MEA. Hence, this work provides both a scalable methodology to stabilise an important future membrane technology, and a clear mechanistic understanding of how this targeted laser modification acts to optimise the three-phase interface of HT-PEMFCs, which can have impact across a wide array of applications. High-temperature proton exchange membrane fuel cells offer efficient solutions to complex fuel cell challenges, including fuel flexibility and heat management. Here the authors demonstrate that laser-scribed membranes improve fuel cell durability and boost peak power density by over 50%, providing a more stable and scalable approach for high performance fuel cells. [ABSTRACT FROM AUTHOR]

This study introduces a novel hybrid system combining direct ammonia-fueled SOFC and PEMFC, incorporating a Pd–Ag membrane for efficient H 2 purification and recirculation at the PEMFC anode. The membrane effectively separates H 2 and N 2 with low energy consumption compared to conventional methods, ensuring a steady H 2 supply to the PEMFC. The N 2 byproduct also offers supplementary revenue potential. A thermodynamic model based on experimental data is developed for the Pd–Ag membrane, and multi-objective optimization is employed to enhance both system efficiency and economic performance. Results show that with H 2 recirculation, the system achieves an electrical efficiency of 67.2%, representing a 4.65% improvement over conventional SOFC-PEMFC setups. Economic analysis estimates an additional annual profit of $309,000 from N 2 recovery, with a payback period of 2.55 years. This research contributes to advancing ammonia-fueled system by introducing a highly efficient and economically viable solution for power generation systems. [Display omitted] • Ammonia fueled hybrid SOFC system with electrical efficiency of 67.2%. • The system is characterized by a Pd–Ag membrane for H 2 purification. • Recycling of H 2 at the PEMFC anode is first achieved in ammonia fueled cell. • Thermodynamic model of the Pd–Ag membrane is constructed. • The recovery of N 2 generates an additional profit of $309,000 per year. [ABSTRACT FROM AUTHOR]

Straight parallel graphite-based flow fields are experimentally assessed to evaluate the effect of geometrical parameters on the performance of polymer electrolyte membrane fuel cell. A 1+1D fuel cell model is exploited to evaluate the local operating conditions occurring along various positions of the flow field channel for different load requirements. The estimated operating conditions are implemented in a zero-gradient hardware to perform a broad experimental campaign, conducting tests under controlled and uniform operating conditions. The achieved experimental results depict the impact of the flow field geometry along different positions of the flow field channel under real operating conditions, identifying the individual contributions of the geometric parameters on water transport, oxygen transport and electrical resistance. The proposed methodology provides detailed information on the local operation of a large-area bipolar plate using a small-area sample, demonstrating the effect of rib and channel geometrical parameters on real-world operation of a PEMFC. [Display omitted] • Development of a novel methodology for optimizing bipolar plate geometry. • Evaluation of local real-world operating conditions within a fuel cell stack. • Experimental optimization of flow field geometry using zero-gradient hardware. • Effect of channel and rib dimensions on local fuel cell stack performance. • Impact of flow field geometry on electrical contact and mass transport resistance. [ABSTRACT FROM AUTHOR]

The article is devoted to the development of simulation model in the MATLAB Simulink software environment of an electric vehicle hybrid traction drive based on fuel cells and lithium battery. The applied topologies of battery and hybrid traction drives are considered. A traction drive model has been synthesized, in which the main energy source is a fuel cell (FC) with a proton exchange membrane (PEM), and the unevenness of the transport load is smoothed out by a high-power buffer storage unit (BSU) based on a lithium-titanium-oxide (LTO) battery. The dependence of the required BSU capacity on the power of the primary source, reduced to a ton of vehicle weight, was obtained. Based on this, the optimal range of hybrid power plant parameters was determined (FC power from 5 to 11 kW/t, LTO battery capacity from 6 to 10 Ah/t) when driving according to the WLTC load cycle. The calculated fuel consumption in this case was 0.56 kg/(km-t), and the time of included state of FC was 94.53%. [ABSTRACT FROM AUTHOR]

Recirculation of the unconsumed anodic gas present in the exhaust stream of Proton Exchange Membrane Fuel Cells (PEMFC) represents a solution frequently used for improving the utilization efficiency of hydrogen. The design of an anodic recirculation system (ARS) can include an ejector that carries the recuperated hydrogen stream directly into the fuel supply line. Compared to pumps, ejectors have no moving parts and do not require power to work, thus increasing the overall efficiency of the cell. On the other hand, they are sensitive to load changes and need an attentive design process. Nozzle diameter and position, convergent and divergent angle, the ratio between nozzle and mixing chamber diameters are several parameters that are usually optimized by trial and error. In this work the development and validation of a 3D CFD model for an ejector to be used on a 5000 W PEMFC was performed. In addition, three new geometries of ejectors to be coupled with 3000 W, 1000 W and 300 W fuel cells were designed. Finally, the scalability and convenience of an ejector for different static power requests were assessed. • Validation of a 3D CFD model for and ejector used in a PEMFC recirculation system. • Definition of scaled versions of the original ejector using optimal "rule of thumb" ratio from literature. • Discussion on feasibility of the prototyping and mass production of this family of ejector with additive manufacturing. [ABSTRACT FROM AUTHOR]

Determining the State-of-Health (SoH) of fuel cell systems during operation is vital for implementing model-based control strategies that aim to minimize degradation and extend the fuel cell lifetime. This paper introduces a novel observer architecture designed to estimate the internal states as well as the SoH of fuel cell systems in real time. The proposed observer offers three key advantages: (1) it decouples the dynamics of internal states from SoH, thus enhancing numerical stability, (2) by incorporating multiple measurement points, assessing the SoH for various components within the fuel cell (e.g. membrane, catalyst layer) becomes possible, and (3) in combination with the used physical real-time capable model, the observer architecture facilitates real-time evaluation of the SoH during dynamic operation. The observer's benefits are demonstrated through simulations and measurement data. • Decoupled estimation of internal states and State-of-Health parameters. • Physically meaningful estimation of internal states and State-of-Health. • State-of-Health estimation of multiple PEM fuel cell components (e.g. membrane). • Real-time evaluation for a wide range of operating points during dynamic operation. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: Fe–Mn dual-atom catalysts exhibit superior oxygen reduction reaction (ORR) activity and stability, with high half-wave potentials in both alkaline and acidic conditions. Synergistic Mn incorporation effectively anchors Fe atoms, mitigates the Fenton reaction, and enhances the durability of ORR catalysts. Advanced characterization and density-functional theory calculations reveal Mn-induced electronic structure modifications, promoting superior ORR kinetics and active site performance. (FeMn-DA)-N-C catalysts show remarkable potential for practical fuel cell applications. The ability to unlock the interplay between the activity and stability of oxygen reduction reaction (ORR) represents an important endeavor toward creating robust ORR catalysts for efficient fuel cells. Herein, we report an effective strategy to concurrent enhance the activity and stability of ORR catalysts via constructing atomically dispersed Fe–Mn dual-metal sites on N-doped carbon (denoted (FeMn-DA)–N–C) for both anion-exchange membrane fuel cells (AEMFC) and proton exchange membrane fuel cells (PEMFC). The (FeMn-DA)–N–C catalysts possess ample dual-metal atoms consisting of adjacent Fe-N4 and Mn-N4 sites on the carbon surface, yielded via a facile doping-adsorption-pyrolysis route. The introduction of Mn carries several advantageous attributes: increasing the number of active sites, effectively anchoring Fe due to effective electron transfer to Mn (revealed by X-ray absorption spectroscopy and density-functional theory (DFT), thus preventing the aggregation of Fe), and effectively circumventing the occurrence of Fenton reaction, thus reducing the consumption of Fe. The (FeMn-DA)–N–C catalysts showcase half-wave potentials of 0.92 and 0.82 V in 0.1 M KOH and 0.1 M HClO4, respectively, as well as outstanding stability. As manifested by DFT calculations, the introduction of Mn affects the electronic structure of Fe, down-shifts the d-band Fe active center, accelerates the desorption of OH groups, and creates higher limiting potentials. The AEMFC and PEMFC with (FeMn-DA)–N–C as the cathode catalyst display high power densities of 1060 and 746 mW cm−2, respectively, underscoring their promising potential for practical applications. Our study highlights the robustness of designing Fe-containing dual-atom ORR catalysts to promote both activity and stability for energy conversion and storage materials and devices. [ABSTRACT FROM AUTHOR]

The correction notice for the paper "Integrating Fiber Sensing for Spatially Resolved Temperature Measurement in Fuel Cells" in Energies addresses errors in author affiliations, figure legends, table details, and missing citations. The study focuses on enhancing temperature control and health monitoring in fuel cells using fiber optic sensors integrated into bipolar plates. The research aims to mitigate hotspots, improve performance, and prolong the service life of fuel cells through precise temperature monitoring. Further advancements are needed to address technical challenges and optimize fuel cell technology for efficient thermal management. [Extracted from the article]

Hydrogen fuel cell water-thermal management systems suffer from slow response time, system vibration, and large temperature fluctuations of load current changes. In this paper, Logistic chaotic mapping, adaptively adjusted inertia weight and asymmetric learning factors are integrated to enhance the particle swarm optimization (PSO) algorithm and combine it with fuzzy control to propose an innovative improved particle swarm optimization-Fuzzy control strategy. The use of chaotic mapping to initialize the particle population effectively enhances the variety within the population, which subsequently improves the ability to search globally and prevents the algorithm from converging to a local optimum solution prematurely; by improving the parameters of learning coefficients and inertia weight, the global and local search abilities are balanced at different stages of the algorithm, so as to strengthen the algorithm's convergence certainty while reducing the dependency on expert experience in fuzzy control. In this article, a fuel cell experimental platform is constructed to confirm the validity and efficiency of the recommended strategy, and the analysis reveals that the improved particle swarm optimization (IPSO) algorithm demonstrates better convergence performance than the standard PSO algorithm. The IPSO-Fuzzy-PID management approach is capable of providing a swift response and significantly diminishing the overshoot in the system's performance, to maintain the system's safe and stable execution. [ABSTRACT FROM AUTHOR]

Although metal‐organic frameworks (MOFs) and metalo hydrogen‐bonded organic frameworks (MHOFs) are designed as promising solid‐state proton conductors by incorporating various protonic species intrinsically or extrinsically, design and development of such materials by employing the concept of proton conduction through coordinated polar protic solvent is largely unexplored. Herein, we have constructed two proton‐conducting materials having different solvent coordinated metal cationic species: In‐H2O‐MOF, ({[In(H2O)6][In3(Pzdc)6] ⋅ 15H2O}n; H2Pzdc: pyrazine‐2,3‐dicarboxylic acid) with coordinated water molecules from hexaaquaindium cationic species, and MHOF‐4, ([{Co(NH3)6}2(2,6‐NDS)2(H2O)2]n; 2,6‐H2NDS: 2,6‐naphthalenedisulfonic acid) with coordinated ammonia from hexaammoniacobalt cationic species. Interestingly, higher proton conductivity was achieved for In‐H2O‐MOF (1.5×10−5 S cm−1) than MHOF‐4 (6.3×10−6 S cm−1) under the extreme conditions (80 °C and 95 % RH), which could be attributed to enhanced acidity of coordinated water molecules having much lower pKa value than that of coordinated ammonia. Greater charge polarization on hydrogen atoms of In3+‐coordinated water molecules than that of Co2+‐coordinated ammonia led to the high conductivity of In‐H2O‐MOF, as evident by quantum chemical studies. Such a comparative study on metal‐coordinated protic polar solvents in achieving proton conduction in crystalline solids is yet to be made. [ABSTRACT FROM AUTHOR]

Inorganic-organic composite proton exchange membranes (PEMs) are promising substitutes in proton exchange membrane fuel cells. To improve the compatibility between inorganic fillers and polyelectrolytes, along with alleviating filler aggregation, a series of composite PEMs incorporating both sulfonated titanium dioxide nanotubes (sTiNT) and graphitic carbon nitride nanosheets (g-C 3 N 4) into sulfonated poly (aryl ether sulfone) s (SPAES) have been prepared. The distinct morphology of sTiNT and g-C 3 N 4 , coupled with their respective sulfonic acids and amine/imine functionalities, endow the fillers with exceptional compatibility and dispersivity within SPAES. The obtained SPAES/sTiNT/g-C 3 N 4 membranes exhibit superior thermal, size and mechanical stability, robust oxidative resistance, together with high proton conductivity. The SPAES/sTiNT/g-C 3 N 4 (1/3) membrane particularly exhibits proton conductivity of 202 mS/cm and swelling below 10% (90 °C), a hydrogen fuel cell output of 512 mW/cm2 (80 °C), which is 1.6 times of the SPAES membrane. The results suggest the great potential of multi-filler compositing strategy for alternative PEMs exploration. [Display omitted] • Sulfoalkoxyl-functionalized titanium nanotubes (sTiNT) have been synthesized. • STiNT and g-C 3 N 4 nanosheets are co-doped into SPAES matrix to prepare PEMs. • 1D/2D fillers co-doped PEMs exhibit exceptional compatibility and dispersivity. • Enhanced dimensional stability and conductivity result from co-doping strategy. • SPAES/sTiNT/g-C 3 N 4 (1/3) has 1.2 times higher σ and 1.6 times better power output. [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cell (PEMFC) technology is vital for a cleaner and more sustainable future, offering high efficiency, quiet operation, fuel flexibility, and zero‐emission energy production with versatile applications. The drawbacks of PEMFC include its high cost, susceptibility to degradation, and challenges in scaling up production for commercial use. The gas diffusion layer (GDL), the catalyst layer (CL), and the polymer electrolyte are all very important parts of fuel cell technology. Through the optimization of these components, researchers may strive to develop fuel cells that are more efficient, cost‐effective, durable, and high‐performing, therefore enabling the provision of clean and sustainable energy. In this article, we have reviewed the various components of GDL, CL, and polymer electrolyte materials and their impact on the performance of PEMFC. The various characteristics of the GDL such as porosity, hydrophobic/hydrophilic, polytetrafluoroethylene (PTFE), and carbon materials, are fully discussed in this review article. These topics also cover the CL's properties, including the catalyst, carbon support, ionomer, and solvent. Explore the different polymer electrolytes that are based on aliphatic Nafion and aromatic hydrocarbons‐based membrane. Finally, this review paper gives suggestions for the way forward in regard to creating electrodes and electrolytes for PEMFCs that are cost‐effective, efficient, and durable. [ABSTRACT FROM AUTHOR]

Inspired by natural bifurcated systems, a bionic microchannel system with tree-like topological structure is proposed, and applied for thermal management of proton exchange membrane fuel cell (PEMFC). The tree-like microchannel is optimized based on the minimization of flow resistance under steady laminar and pulsating flow conditions, respectively. Finite element simulations and microfluidic experiments are carried out for pulsating flow in the tree-like microchannel to determine its heat transfer performance. The results show that the optimized successive diameter ratio for the pulsating flow in a symmetric and dichotomous tree-like network is 0.707 (≈2−1/2), which is different from that of steady laminar flow (0.794≈2−1/3) known as Murray's law. Compared with steady flow, the application of sinusoidal-wave and rectangular-wave pulsating flow in a tree-like microchannel can further improve both the heat transfer efficiency and temperature uniformity. The tree-like microchannel with a length ratio of 2−2/3≈0.630 and diameter ratio of 2−1/3≈0.794 shows best performance under steady and pulsating flow modes. The present work has important theoretical significance for understanding the mechanism of natural bifurcated systems, and may provide theoretical basis and technical support for the industrial applications of bionic tree-like microchannel in thermal management of fuel cell and microelectronic device cooling etc. [Display omitted] • Bionic tree-like microchannel is designed for thermal management of PEMFC. • Optimized successive ratio of tree-like microchannel with pulsating flow is derived. • Thermal-hydraulic performance of bionic microchannel is investigated by FEM. • Mathematical model of bionic microchannel is validated by microfluidic experiment. [ABSTRACT FROM AUTHOR]

Green hydrogen (H2) is an essential component of global plans to reduce carbon emissions from hard‐to‐abate industries and heavy transport. However, challenges remain in the highly efficient H2 production from water electrolysis powered by renewable energies. The sluggish oxygen evolution restrains the H2 production from water splitting. Rational electrocatalyst designs for highly efficient H2 production and oxygen evolution are pivotal for water electrolysis. With the development of high‐performance electrolyzers, the scale‐up of H2 production to an industrial‐level related activity can be achieved. This review summarizes recent advances in water electrolysis such as the proton exchange membrane water electrolyzer (PEMWE) and anion exchange membrane water electrolyzer (AEMWE). The critical challenges for PEMWE and AEMWE are the high cost of noble‐metal catalysts and their durability, respectively. This review highlights the anode and cathode designs for improving the catalytic performance of electrocatalysts, the electrolyte and membrane engineering for membrane electrode assembly (MEA) optimizations, and stack systems for the most promising electrolyzers in water electrolysis. Besides, the advantages of integrating water electrolyzers, fuel cells (FC), and regenerative fuel cells (RFC) into the hydrogen ecosystem are introduced. Finally, the perspective of electrolyzer designs with superior performance is presented. [ABSTRACT FROM AUTHOR]

Bipolar plates are one of the main components of proton exchange membrane fuel cells (PEMFCs). Their functions include distributing reactants, supporting the cell, and conducting heat and electricity. They account for a significant proportion of the fuel cell stack's weight and volume. The main materials currently used for bipolar plates are graphite and stainless steel. Aluminium has a much lower density than steel and is easier to form than both steel and graphite. Its use, therefore, would allow fuel cells with higher power densities but is hindered due to it being prone to corrosion. This work focused on the development of corrosion-resistant and conductive coatings to address this issue. Carbon coatings with Ti and Cr adhesion layers were deposited on aluminium substrates using closed-field unbalanced magnetron sputtering. These coatings were tested for corrosion properties and performance on the cathode side of a single-cell fuel cell. Coated aluminium samples were also tested for their ability to maintain their corrosion protection after being formed. Coating with a Cr adhesion layer outperformed that with a Ti adhesion layer in both forming and fuel cell tests, demonstrating much lower performance degradation after accelerated stress testing. [ABSTRACT FROM AUTHOR]

By utilizing a chemical method, carbon nanotubes (CNTs) were mixed with polyvinylpyrrolidone (PVP) to prepare a nanomembrane intended for use as a proton exchange membrane in PEM fuel cells. Various tests were conducted to characterize the nanomembrane, including the examination of its morphology using a scanning electron microscope (SEM) and the analysis of its physical properties using XRD. An electrolyzer unit was developed to supply hydrogen gas to the PEM fuel cell, and electrochemical parameters such as the relationship between hydrogen volume and current, as well as the correlation between voltage and current, were investigated. Through electrochemical modeling and optimization of the nanomembrane, impressive results were achieved with a cell voltage of 1.24V and a current of 2.5A. [ABSTRACT FROM AUTHOR]

Pt on carbon black (Pt/C) has been widely used as a catalyst for both ORR and hydrogen oxidation reaction (HOR), but its stability is compromised due to carbon corrosion and catalyst poisoning, leading to low Pt utilization. To address this issue, this study suggests replacing carbon black with graphene in the catalyst layer. The importance of this work lies in the detailed examination of novel electrocatalysts with high electrocatalytic activity for large-scale power generation. In this paper, we discuss the use of regulatory techniques like structure tuning and composition optimization to construct nanocatalysts impregnated with noble and non-noble metals on graphene supports. Finally, it highlights the limitations and advantages of these nanocatalysts along with some future perspectives. Our objective is that this summary will help in the research and rational design of graphene-based nanostructures for efficient ORR electrocatalysis. The results of this study showed that the performances of graphene-based catalysts show high electrochemical active surface areas for Pt-Fe/GNPs and Pt-Ni/GNPs catalysts (132 and 136 m2 g−1, respectively) at 100 operating cycles. Also, high current densities and power densities were observed for Pt3-Ni/G and Pt-Co/G catalysts used at the cathode. The values for current density were 1.590 and 1.779 A cm−2, respectively, while the corresponding values for power density were 0.57 and 0.785 W cm−2. [ABSTRACT FROM AUTHOR]

Extending the operation of proton exchange membrane fuel cells (PEMFCs) at high temperature (i.e., 120 °C) and/or low relative humidity (< 50% RH) remains a significant challenge due to dehydration and subsequent performance failure of the Nafion electrolyte. We approached this problem by integrating the Nafion matrix with a novel hybrid nanofiller, created through direct growth of TiO2 nanoparticles on the surface of carbon nanotubes. This synthetic approach allowed to preserve an effective nanodispersion of Titania particles in the hosting matrix, thereby boosting dimensional stability, hydrophilicity, and physiochemical properties of the Nafion/MWCNTs-TiO2 (NMT-x) nanocomposites compared to parental Nafion. At optimal concentration (i.e., 3 wt% with respect to the polymer), the nanocomposite membrane exhibited high transport characteristics with impressive water retention capabilities, resulting in a proton conductivity of 8.3 mS cm− 1 at 80 °C and 20% RH. The Titania nanoparticles plays a key role in retaining water molecules even under dehydrating conditions, while also directly contributing to proton transport. Additionally, the long carbon nanotubes promote the formation of additional paths for proton conductivity. These combined features enabled the NMT-3 membrane to achieve a maximum power output of 307.7 mW/cm2 in a single H2/air fuel cell (5 cm2 active electrode area and 0.5 mg Pt/cm2 at both electrodes) under very challenging conditions, specifically at 120 °C and 30% RH. This represents a significant advancement towards overcoming the limitations of traditional Nafion membranes and opens up new possibilities for high-temperature, low-humidity H2/air fuel cell applications. [ABSTRACT FROM AUTHOR]

This article is focused on the construction of a stand-alone residential 5-kW hybrid power system to feed different domestic loads at a typical house in Thi-Qar City, Iraq, including lighting loads, Table fan, Smartphone charger, TV, Microwave and Cooler. The stand-alone residential 5-kW hybrid power system consists of PV generator, PEMFC, storage batteries, Electrolyzer and hydrogen tank. The battery and hydrogen subsystem, composed of a fuel cell (FC), electrolyzer, and hydrogen storage tank, act as energy storage and support systems. The research in steps includes the design of the hybrid system. A program has been used in MATLAB to size system components in order to match the load of the site in the most cost-effective way. Evaluation of the economic feasibility of the same hybrid system when using a solar tracking system for photovoltaic cells. The simulation results demonstrate the hybrid system's ability to supply the required electrical energy to the loads, as well as the increase in hydrogen production when using the solar tracking system, which makes it possible to store excess hydrogen in the long term for later use when the photovoltaic energy decreases according to the seasons of the year. [ABSTRACT FROM AUTHOR]

Hydrogen technologies have the potential to reduce aviation's CO2 emissions but come with many challenges. This paper introduces a scalable hydrogen fuel cell model tailored for system integration analysis in early aircraft design phases. The model focuses on Proton Exchange Membrane Fuel Cells (PEMFCs) and is based on thermodynamic equations and empirical data to simulate performance under different ambient and operating conditions; it also includes a simplified model of the Balance of Plant (BOP) systems and is implemented in OpenModelica. The model performance is validated through a comparison of the simulated polarization curves with real datasheet data. A case study highlights the peculiarities of this model by studying the sizing of the fuel cell stacks for a modified ATR 72 aircraft. The developed model effectively supports the early design exploration of the aircraft with a greater level of detail for system integration studies, essential to better explore the potential of aircraft featuring hydrogen-based power systems. [ABSTRACT FROM AUTHOR]

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An ionomer strategy is introduced to deal with two major performance‐limiting issues for the proton exchange membrane fuel cells (PEMFCs) operating under low platinum (Pt) and low humidity. Specifically, the highly hydrophilic multiple‐valence Anderson‐type polyoxometalate (POM) cluster, [MnMo6O18(OH)6]3−, is chosen to covalently graft the perfluorinated polymer, substituting for sulfonate groups as proton carriers in perfluorosulfonic acid (PFSA). The structural and electrochemical characterizations indicate that this POM cluster, with large size, charges delocalization among multiple terminal oxygen atoms, and high hygroscopicity, can prevent the ionomer adsorption, which is believed to induce dense backbone crystallization to hinder O2 permeation at Pt/PFSA interface, and lead to ionomer assemblies with large and well‐connected hydrophilic domains, which are recognized as the channels for efficient oxygen transport as well as proton conduction. Besides, the involvement of redox Mn ions in POM clusters makes the ionomer have capability to scavenge peroxides, which are known as the major chemical agents to degrade the MEA components. Consequently, fuel‐cell cathodes using the POM‐grafted ionomers exhibit significantly lower local O2 transport resistance and higher proton conductivity as compared with the PFSA‐based electrodes; and accordingly, the fuel cells exhibit much‐increased output performance at 50% relative humidity and impressive performance stability. [ABSTRACT FROM AUTHOR]

The performance of hydrogen production by methanol steam reforming and high temperature proton exchange membrane fuel cells on drone lacks the comparison of experimental data, resulting in the overall performance improvement of the system is difficult to evaluate. Therefore, the energy management strategy of methanol reforming high temperature proton exchange membrane fuel cell hybrid power system and state machine is designed and optimized. The performance of this system is analyzed and compared with the flight experiment data of a proton exchange membrane fuel cell hybrid UAV. The results show that the SOC of the system can be stabilized between 70 and 80 during the long cruise phase. The test results show that the maximum hydrogen storage mass density of the hydrogen supply system is increased by 67.6%. The flight time of the system under economic cruise flight of the drone is improved by 29.1%–44.9% with different quality of fuel. Under the maximum flight speed of a certain wind speed, the system can meet the flight requirements and increase the flight time by 31.9% and 17.6% respectively under the wind speed of 1.5 m/s and 4 m/s. Its flight time has been greatly improved, and it has great potential as a drone system. [Display omitted] • Test the performance of system with real flight test data of experimental drone. • The SOC can be stabilized between 70 and 80 during the cruise phase. • The flight time has been improved from 29.1% to 44.9% under economic flight. • The flight time is increased by 31.9% and 17.6% at different wind speeds. [ABSTRACT FROM AUTHOR]

The loss of platinum (Pt) electrochemically active surface area (ECSA) is a critical degradation mode that often becomes a limiting factor for heavy‐duty proton exchange membrane fuel cell vehicles. High surface area carbon supports have been shown to improve Pt dispersion and limit detrimental ionomer‐electrocatalyst interactions due to their large interior pore volume. In this work, using automated scanning transmission electron tomography, the degradation of nanoparticles located on the interior versus exterior surfaces of the carbon support is compared following a catalyst‐specific accelerated stress test (AST) of 90,000 voltage cycles between 0.6 V to 0.95 V. The results reveal a notable increase in median particle size for both interior and exterior Pt catalyst particles, with a slightly higher increase in particle size distribution and loss of specific surface area for the particles located on the exterior carbon surface. The fraction of Pt nanoparticles that reside within the interior of the carbon support also increased following the AST test, accompanied by evidence of an increase in average carbon mesopore size. The results shed light on the degradation mechanisms affecting electrochemical properties and the enhanced particle accessibility at lower relative humidity. [ABSTRACT FROM AUTHOR]

Accurate prediction of the remaining useful life (RUL) of proton exchange membrane fuel cells (PEMFCs) is essential for maximizing their operational lifespan. However, existing methods often face limitations in two key areas: long-term prediction (beyond 168 h, or one week) and adaptability to varying operating conditions. To address these challenges, we propose a novel self-adaptive digital twin (SADT) model for RUL prediction of PEMFCs. Our approach uniquely integrates a deep convolutional neural network to generate robust health indicators (HIs) that maintain consistent monotonicity across diverse operating conditions. Additionally, we introduce a novel quantile Huber loss (QH-loss) function to enhance prediction accuracy and incorporate a transfer learning technique to improve adaptability under varying operational scenarios. Experimental results on PEMFC degradation datasets demonstrate that our method outperforms state-of-the-art techniques in long-term prediction accuracy, highlighting its potential to significantly extend fuel cell lifetimes. • A novel self-adaptive digital twin for predicting RUL of the PEMFC. • Transfer Learning enhanced RUL prediction accuracy and adaptability. • Universal monotonic HI applicable to various PEMFC operating conditions. [ABSTRACT FROM AUTHOR]

The fuel cell vehicle is one of the essential directions for developing new energy vehicles. But heat dissipation is a critical technical difficulty that needs to be solved urgently. Nano-coolant is a promising coolant that can potentially replace the existing coolant of a fuel cell. However, its thermal conductivity has a significant impact on heat dissipation performance, which is closely related to nanoparticles' thermal conductivity, nanoparticles' volume fraction, and the nano-coolant temperature. Many scholars have created the thermal conductivity models for nano-coolants to explore the mechanism of nano-coolants' thermal conductivity. At present, there is no unified opinion on the mechanism of the micro thermal conductivity of the nano-coolant. Hence, this paper proposed a novel model to predict the thermal conductivity of ethylene glycol/deionized water-based nano-coolants. A corrected model was designed based on the Hamilton & Crosser model and nanolayer theory. Finally, a new theoretical model of nano-coolant thermal conductivity suitable for fuel cell vehicles was constructed based on the base fluid's experimental data. [ABSTRACT FROM AUTHOR]

Power characteristics are important indicators of fuel cell performance. In the actual operation of fuel cells, changes in operating conditions lead to variations in their power characteristics. Therefore, it is imperative to explore the impact of operating conditions on power characteristics. This paper analyzes the factors influencing fuel cell power and uses sensitivity analysis to investigate how different factors affect fuel cell performance. The operating parameters are optimized using a Bayesian-optimized Gaussian process regression model. The research results indicate that temperature has the greatest impact on fuel cell power, followed by stoichiometry and backpressure. The Bayesian-optimized Gaussian process regression model performs the best, reducing its RSME from 0.1 to 0.0556. Residual analysis and regression characteristic analysis verify the optimized model's improved fitting and regression characteristics. Based on the Bayesian–Gaussian process regression model, the optimized operating parameters are obtained for maximum power: a temperature of 80 °C, stoichiometry of 4, and backpressure of 1.7 bar. This paper provides theoretical support for improving fuel cell performance. [ABSTRACT FROM AUTHOR]

Fuel cells are the most promising energy source for the future energy demand. The automobile industry is looking at the integration of fuel cells with electric vehicles (EV). This integration comes with many challenges like dynamic operational behaviors. For operating the fuel cell with maximum efficiency, this work proposes an Adaptive Neuro Fuzzy Inference System (ANFIS) based Maximum Power Point Tracking (MPPT) method. The hydrogen flow rate, pressure and stack temperature are the parameters considered to track the maximum power point of the fuel cell. The ANFIS-MPPT algorithm has been integrated with the 1.26 kW fuel cell in MATLAB/Simulink® and validated in different scenarios like dynamic variation in hydrogen pressure, stack temperature, load variation. The performance has been observed and compared with the conventional MPPT algorithms of Perturb and Observe (P&O) algorithm and Incremental Conductance (InC) algorithm. The proposed ANFIS-MPPT algorithm improves the power stability by 10–15% than the P&O and InC methods. Also, the proposed ANFIS-MPPT has 30% faster response as compared to the P&O algorithm, and 23% than the InC algorithm. From the analysis, it is observed that the ANFIS, P&O and InC methods are having the response time of 2.5 s, 3.6 s and 4.5 s respectively. Also the ANFIS method delivers the maximum power output of 1.26 kW, whereas the P&O and InC deliver 1.13 kW, 1.19 kW respectively. The detailed simulation analysis and results are presented in this paper. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is an advantageous polymer due to its renewable nature, low cost, environmental compatibility, biocompatibility, biodegradability, chemical stability, and ease of modification. With these advantages, BC is an interesting candidate for the development of novel eco-friendly materials for proton-exchange membrane (PEM) applications. However, its practical applications have been limited by its relatively high dispersion in water, which usually occurs during the operation of proton-exchange membrane fuel cells (PEMFCs). In addition, the proton conductivity of bacterial cellulose is poor. In this study, functionalized BC modified with 3-aminopropyltriethoxysilane (APTES) was prepared using a solvent casting method to enhance its performance. The results showed that the water stability of the modified BC membrane was significantly improved, with the contact angle increasing from 54.9° to 103.3°. Furthermore, the optimum ratio of BC and APTES was used to prepare a proton-exchange membrane with a maximum proton conductivity of 62.2 mS/cm, which exhibited a power generation performance of 4.85 mW/cm2 in PEMFCs. It is worth mentioning that modified BC membranes obtained by combining an alkaline proton carrier (-NH2) with BC have rarely been reported. As fully bio-based conductive membranes for PEMFCs, they have the potential to be a low-cost, eco-friendly, and degradable alternative to expensive, ecologically problematic fluoric ionomers in short-term or disposable applications, such as biodegradable electronics and portable power supplies. [ABSTRACT FROM AUTHOR]