Search Results (662)

High-Temperature Proton-Exchange Membrane Fuel Cells (HT-PEMFCs) represent a promising clean energy technology and are valued for their fuel flexibility and simplified balance of plant. Their commercialization, however, is critically hindered by the prohibitive cost and resource scarcity of platinum-group metal (PGM) catalysts. The challenge is amplified in the phosphoric acid (PA) electrolyte of HT-PEMFCs, where the severe anion poisoning of PGM active sites necessitates impractically high catalyst loadings. This review addresses the urgent need for cost-effective alternatives by providing a comprehensive assessment of recent advancements in non-precious metal (NPM) catalysts for the oxygen reduction reaction (ORR) in HT-PEMFCs. It systematically explores synthesis strategies and structure–performance relationships for emerging catalyst classes, including transition metal compounds, metal–nitrogen–carbon (M-N-C) materials, and metal-free heteroatom-doped carbons. A significant focus is placed on M-N-C catalysts, particularly those with atomically dispersed Fe-Nx active sites, which have emerged as the most viable replacements for platinum due to their high intrinsic activity and notable tolerance to phosphate poisoning. This review critically analyzes key challenges that impede practical application, such as the trade-off between catalyst activity and stability, mass transport limitations in thick electrodes, and long-term degradation in the harsh PA environment. Finally, it outlines future research directions, emphasizing the need for a synergistic approach that integrates computational modeling with advanced operando characterization to guide the rational design of durable, high-performance catalysts and electrode architectures, thereby accelerating the path to commercial viability for HT-PEMFC technology. Full article

This paper presents a calibrated and dynamically responsive simulation framework for hybrid energy systems that integrate Proton Exchange Membrane Fuel Cells (PEMFCs) and batteries, targeting applications in light commercial vehicles (LCVs). The aim is to support the design and assessment of energy management strategies (EMS) under realistic operating conditions. A publicly available PEMFC model is used as the starting point. To improve its representativeness, calibration is performed using experimental polarization curve data, enhancing the accuracy of the stack voltage model, and the air compressor model—critical for maintaining stable fuel cell operation—is adjusted to reflect measured transient responses, ensuring realistic system behavior under varying load demands. Quantitatively, the calibration results are strong: the R² values of both the fuel cell polarization curve and the overall system efficiency are around 0.99, indicating excellent agreement with experimental data. The calibrated model is embedded within a complete hybrid vehicle powertrain simulation, incorporating longitudinal dynamics and control strategies for power distribution between the battery and fuel cells. Simulations conducted under WLTP driving cycles confirm the model’s ability to replicate key behaviors of PEMFC-battery hybrid systems, particularly with respect to dynamic energy flow and system response. In conclusion, this work provides a reliable and high-fidelity simulation environment based on empirical calibration of key subsystems, which is well suited for the development and evaluation of advanced EMS algorithms. Full article

Proton-exchange membrane fuel cells (PEMFCs) stand out for their exceptional efficiency, high power density, and zero emissions, as they produce merely heat and water as byproducts. Appropriate and robust thermal management is the key to ensuring the maximum efficiency of the fuel cell (FC) as its optimum operating temperature is 70~80 °C. The current study was designed for the parametric evaluation of coolant channels (CCs) based on the multi-pass serpentine flow field (MPSFF) to investigate the relationship between channel geometry and thermal performance in PEM fuel cells, offering novel insights into optimal design configurations for improved thermal management. Six 3D computational models of PEMFCs with varying numbers of coolant channels were created and evaluated using COMSOL 6.2. The acquired results suggested that longer channel lengths with more serpentine turns cause the maximum number of hot spots around turns and offer a maximal pressure drop, whereas increasing the number of channels results in a uniform thermal distribution and leads to a minimal pressure drop. The findings indicate that systematic variations in geometrical configurations of MPSFFs can significantly enhance thermal uniformity and minimize the pressure drop, offering valuable insights for improving the efficiency of PEMFCs. Full article

This study proposes a MPL (microporous layer)–GDL (gas diffusion layer) microstructure reconstruction method based on a novel random reconstruction algorithm. Then the Shan–Chen multi-component and multi-phase lattice Boltzmann method (SC-LBM) is used to systematically describe the influence of different contact angle distributions on the drainage characteristics of the GDL of proton exchange membrane fuel cells (PEMFCs). Meanwhile, the breakthrough time of liquid water, steady-state time, and liquid water saturation are compared. The results show that with the increase in contact angle, the time for the first droplet breakthrough and the steady-state time are significantly shortened, and the saturation of liquid water gradually decreases at the steady state, indicating that increasing hydrophobicity can effectively improve the drainage capacity of the GDL. Several double-gradient and three-gradient contact angle distribution schemes are studied, and it is found that the gradient structure with increasing contact angles along the direction of water flow will lead to prolonged steady-state time and elevated water saturation, which is not conducive to drainage. This study analyzes the drainage process under different wettability gradients considering aspects such as the droplet morphology evolution, flow path, and water distribution mechanism, clarifying the key role of gradient design in GDL water management. This work also provides a theoretical basis and design guidelines for wettability optimization in the GDL of PEMFCs. Full article

Water management is a critical issue for improving both the performance and durability of proton exchange membrane fuel cells (PEMFCs). A gas diffusion layer (GDL), as a porous medium, plays a key role in liquid water removal, reactant supply, and ensuring uniform distribution within the cell. Local perforations in the GDL are known to enhance water management capability. To further improve mass transfer, the effects of the perforation location in the GDL on PEMFC performance were investigated under different flow rates. The performance was compared and analyzed for three cases with GDL on the cathode side: a conventional GDL, a GDL perforated only under the channel, and a GDL with the perforations offset toward the rib by half the channel width. As a result, the offset of the perforations led to improved performance and enhanced uniformity, and the effect of the offset became more significant at higher flow rates. The under-channel and offset cases showed slight performance increases of 3.02% and 3.11% under the cathode stoichiometric ratio (SR_c) of 1.2, but more significant improvements of 4.72% and 5.29% were observed under the SR_c of 3.0. These results suggest the necessity of considering the flow field when designing a perforated GDL. Full article

The optimum degree of sulfonation (DS) for sulfonated poly(ether ether ketone) (SPEEK) membranes is determined by comprehensive characterization results, including proton conductivity, swelling ratio, water uptake, chemical stability, thermal stability, mechanical indicators, and proton exchange membrane fuel cell (PEMFC) performance. The PEMFC with a membrane electrode assembly containing a SPEEK-62 (DS = 62%) membrane realizes the power density of 482.08 mW/cm², surpassing that of commercial Nafion-212 under identical conditions. In the crucial Fenton test for durability, the SPEEK-51 membrane demonstrated outstanding dimensional and chemical stability, with a decomposition time of up to 137 min, far surpassing the durability of SPEEK-62 or other membranes with a higher DS. The results indicate that in comparison to the SPEEK-67 membrane as reported in the literature, SPEEK membranes with a DS = 51~62% hold great potential for future applications in PEMFC, and further modifications of these membranes can be a promising approach to enhance the conductivity while maintaining good chemical stability. Full article

The increasing depletion of fossil fuels and their environmental impact have led to the development of fuel cell hybrid electric vehicles. By combining fuel cells with batteries, these vehicles offer greater efficiency and zero emissions. However, their energy management remains a challenge requiring advanced strategies. This paper presents a comparative study of two developed energy management strategies: a deterministic rule-based approach and a fuzzy logic approach. The proposed system consists of a proton exchange membrane fuel cell (PEMFC) as the primary energy source and a lithium-ion battery as the secondary source. A comprehensive model of the hybrid powertrain is developed to evaluate energy distribution and system behaviour. The control system includes a model predictive control (MPC) method for fuel cell current regulation and a PI controller to maintain DC bus voltage stability. The proposed strategies are evaluated under standard driving cycles (UDDS and NEDC) using a simulation in MATLAB/Simulink. Key performance indicators such as fuel efficiency, hydrogen consumption, battery state-of-charge, and voltage stability are examined to assess the effectiveness of each approach. Simulation results demonstrate that the deterministic strategy offers a structured and computationally efficient solution, while the fuzzy logic approach provides greater adaptability to dynamic driving conditions, leading to improved overall energy efficiency. These findings highlight the critical role of advanced control strategies in improving FCHEV performance and offer valuable insights for future developments in hybrid-vehicle energy management. Full article

To further enhance the economic performance of fuel cell vehicles (FCVs), this study develops a model-adaptive model predictive control (MPC) strategy. This strategy leverages the dynamic relationship between proton exchange membrane fuel cell (PEMFC) output characteristics and temperature to track its optimal operating temperature (OOT), addressing challenges of temperature control accuracy and high energy consumption in the PEMFC thermal management system (TMS). First, PEMFC and TMS models were developed and experimentally validated. Subsequently, the PEMFC power–temperature coupling curve was experimentally determined under multiple operating conditions to serve as the reference trajectory for TMS multi-objective optimization. For MPC controller design, the TMS model was linearized and discretized, yielding a predictive model adaptable to different load demands for stack temperature across the full operating range. A multi-constrained quadratic cost function was formulated, aiming to minimize the deviation of the PEMFC operating temperature from the OOT while accounting for TMS parasitic power consumption. Finally, simulations under Worldwide Harmonized Light Vehicles Test Cycle (WLTC) conditions evaluated the OOT tracking performance of both PID and MPC control strategies, as well as their impact on stack efficiency and TMS energy consumption at different ambient temperatures. The results indicate that, compared to PID control, MPC reduces temperature tracking error by 33%, decreases fan and pump speed fluctuations by over 24%, and lowers TMS energy consumption by 10%. These improvements enhance PEMFC operational stability and improve FCV energy efficiency. Full article

The geometric design of flow channels in bipolar plates is one of the critical features of proton exchange membrane fuel cells (PEMFCs), as it determines the power output of the fuel cell and has a significant impact on its performance and durability. The function of the bipolar plate is to guide the transfer of reactant gases to the gas diffusion layer and catalytic layer inside the PEMFC, while removing unreacted gases and gas–liquid byproducts. Therefore, the design of the bipolar plate flow channel is directly related to the water and thermal management of the PEMFC. In order to improve the comprehensive performance of PEMFCs and ensure their safe and stable operation, it is necessary to design the flow channels in bipolar plates rationally and effectively. This study addresses the limitations of existing bipolar plate flow channels by proposing a new coupling of serpentine and radial channels. The distribution of oxygen, water concentrations, and temperature inside the channel is simulated using the multi-physics simulation software COMSOL Multiphysics 6.0. The performance of this novel design is compared with conventional flow channels, with a particular focus on the pressure drop and current density to evaluate changes in the output performance of the PEMFC. The results show that the maximum current density of this novel design is increased by 67.36% and 10.43% compared to straight channel and single serpentine channels, respectively. The main contribution of this research is the innovative design of a new coupling of serpentine and radial channels in bipolar plates, which improves the overall performance of the PEMFC. This study provides theoretical support for the design of bipolar plate flow channels in PEMFCs and holds significant importance for the green development of energy. Full article

This study aims to determine the model parameters of proton exchange membrane fuel cells (PEMFC) by employing the Sea Horse Optimization (SHO) algorithm, a novel metaheuristic approach inspired by natural behaviors. Although conventional algorithms in the literature have achieved considerable success in parametric modeling accuracy, many of them suffer from inherent drawbacks, such as premature convergence and entrapment in local minima. The SHO algorithm, with its adaptive and dynamic nature, is designed to overcome these limitations. To further evaluate its performance, a detailed parametric sensitivity analysis is conducted on SHO-specific control parameters. In this work, experimental polarization data from a Ballard Mark V PEMFC is used as a reference to estimate the equivalent circuit model parameters ${ϵ}_1$, ${ϵ}_2$, ${ϵ}_3$, ${ϵ}_4$, $\beta$, $\lambda$, $R_c$. The SHO algorithm achieved a mean absolute error (MAE) of 0.001079 and a coefficient of determination (R²) of 0.999791, with a model-to-experiment fit ratio of 99.92%. Compared to similar studies reported in the literature, the results indicate that the SHO algorithm offers competitive performance. Moreover, the average convergence time is recorded as 1.74 s for 5000 iteration, highlighting the algorithm’s rapid convergence and low computational cost. Overall, the SHO algorithm is demonstrated to be an efficient, robust, and promising alternative to conventional methods for parameter identification in PEMFC modeling. Full article

In this study, the sensitivity of operating parameters such as the hydrogen and air excess coefficient, cathode inlet pressure, intake relative humidity, and coolant inlet temperature and their effects on the performance of single proton exchange membrane fuel cells (PEMFCs) are experimentally assessed. The results revealed that the fuel cell node voltage increases as the hydrogen and air excess coefficient increases, and the impact of the hydrogen and air excess coefficient on the fuel cell node voltage gradually increases as the current density increases. However, a higher hydrogen and air excess coefficient is not always better. The node voltage increases as the intake pressure increases. However, it is not that a higher intake pressure is always better, but rather that there is an optimal intake pressure value to achieve the best overall performance of the fuel cell. The node voltage increases as the coolant inlet temperature increases at most fuel cell current densities. However, the optimum fuel cell operating inlet temperature is not necessarily higher, as the coolant inlet temperature may have a strong coupling relationship with other operating conditions that will also affect the fuel cell performance. The fuel cell operating inlet temperature may have a strong coupling relationship with the intake relative humidity, and both of these parameters must be well-matched to achieve better fuel cell performance. Full article

This study systematically investigated the physicochemical properties and proton exchange membrane fuel cell (PEMFC) performance of perfluorosulfonic acid (PFSA) membranes with different thicknesses, which were prepared based on the resins produced by Dongyue (China) in comparison with commercial Nafion membranes. It was found that the water uptake of Dongyue membranes is significantly higher than that of Nafion, showing a significant upward trend with the thickness increase. The ion exchange capacity (IEC) of these membranes is ca. 1 mmol·g⁻¹. Moreover, the tensile strength of the Dongyue membrane was positively correlated with the thickness and was significantly higher than that of recast Nafion. Under 80 °C, all Dongyue membranes with various thicknesses (15~45 μm) exhibited PEMFC single-cell performance superior to that of Nafion. The maximum power density is observed with a thickness of 25 μm, reaching 851.76 mW·cm⁻², which is higher than that of Nafion (635.99 mW·cm⁻²). However, the oxidative stability of the prepared Dongyue PFSA series membranes exhibits a slight deficit compared to commercial Nafion membranes. Subsequently, the modification and optimization of preparation processes can be employed to improve the mechanical and chemical stability of Dongyue PFSA membranes. Full article

Proton Exchange Membrane Fuel Cells (PEMFCs) are seen as an alternative for heavy-duty transportation electrification. Powered by a green hydrogen source, they can provide high efficiency and low carbon emissions compared to traditional fuels. However, to be competitive, these systems require high reliability when operated in real-life conditions, as well as safe and efficient operating management. In order to achieve these goals, the X-in-the-loop (also called model-based design) methodology is well suited. It has been largely adopted for PEMFC system development and optimisation, as they are complex multi-component systems. In this paper, a systematic analysis of the scientific literature is conducted to review the methodology implementation for the design and improvement of the PEMFC systems. It exposes a precise definition of each development step in the methodology. The analysis shows that it can be employed in different ways, depending on the subsystems considered and the objectives sought. Finally, gaps in the literature and technical challenges for fuel cell systems that should be addressed are identified. Full article

This study focuses on addressing the issues of water flooding and mass transfer limitations in proton exchange membrane fuel cells (PEMFCs) under high current density conditions. A multi-scale gradient pore gas diffusion layer (GDL) is designed to enhance fuel cell performance. The pore structure is precisely controlled using a self-assembled mold, resulting in the fabrication of a GDL with a gradient distribution of pore diameters ranging from 80 to 170 μm. Experimental results indicate that, with the optimized gradient pore GDL, the peak power density of the fuel cell reaches 1.18 W·cm−², representing a 20% improvement compared to the traditional structure. A mechanism analysis reveals that this structure establishes a concentrated water transport pathway through channels while enabling gas diffusion and transport driven by concentration gradients, thereby achieving the collaborative optimization of gas–liquid transport. This approach offers a novel solution for managing water in PEMFCs operating under high current density conditions, and holds significant implications for advancing the commercialization of PEMFC technology. Full article

This study investigates the chemical stability and leaching behavior of two environmentally sustainable EPDM elastomers filled with circular carbon black (CCB) and recycled carbon black (RCB) when exposed to acidic, fuel cell-like environments. Accelerated aging tests were conducted in sulfuric acid solutions of varying concentrations (1 M, 0.1 M, and 0.001 M) at 90 °C for 1000 h to simulate long-term degradation in proton exchange membrane fuel cell (PEMFC) sealing applications. Complementary hot water extraction tests (HWET) were performed at 80 °C for up to 168 h to evaluate ionic leaching via conductivity measurements. HPLC-DAD analysis was used to assess organic leachates, while surface changes were examined by SEM and thermal transitions by DSC. Results revealed lower leaching and improved surface preservation in the CCB-filled EPDM, which remained below the critical 5 µS/cm ionic conductivity threshold for longer durations than its RCB counterpart. HPLC results showed filler-dependent trends in organic compound release, with CCB EPDM exhibiting higher leaching only under strong acid exposure. SEM confirmed greater surface damage and porosity in RCB EPDM. Overall, both materials demonstrated adequate chemical resistance, but the CCB formulation exhibited superior long-term stability, supporting its use in sustainable PEMFC sealing applications. Full article