Search Results (44)

This review is focused on FC-BENTEN, an advanced synchrotron X-ray experimental database developed at SPring-8 with support from Japan’s New Energy and Industrial Technology Development Organization (NEDO). Designed to advance polymer electrolyte fuel cells (PEFCs) research, FC-BENTEN addresses challenges in improving efficiency, durability, and cost-effectiveness through data-driven approaches informed by materials informatics (MI). Through standardization of protocols for sample preparation, data acquisition, analysis, and formatting, the database ensures high-quality, reproducible data essential for reliable scientific outcomes. FC-BENTEN streamlines metadata creation using automated processes and template-based tools, enhancing data management, accessibility, and interoperability. Security measures include two-factor authentication, safeguarding sensitive information and maintaining controlled user access. Planned integration with MI platforms will broaden data cross-referencing capabilities, facilitate PEFC applications expansion, and guide future research. This review discusses FC-BENTEN’s architectural framework, metadata standardization efforts, and role in advancing PEFC research through a high-throughput experimental workflow. It illustrates how data-driven methods and standardized practices contribute to innovation, underscoring databases’ potential to accelerate next-generation PEFC technologies development. Full article

The impeding ban on per- and polyfluoroalkyl substances (PFAS) prompted researchers to focus on hydrocarbon-based materials as constituents of next-generation proton exchange membranes (PEMs) for polymer electrolyte fuel cells (PEFCs). Here, we report on the fuel cell performance and durability of fluorine-lean PEMs prepared by the post-sulfonation of co-grafted α-methylstyrene (AMS) and 2-methylene glutaronitrile (MGN) monomers into preirradiated 12 µm polyvinylidene fluoride (PVDF) base film. The membranes were subjected to two distinctly different accelerated stress test (AST) protocols performed at open-circuit voltage (OCV): the US Department of Energy-similar chemical AST (90 °C, 30% relative humidity (RH), H₂/air, 1 bar_a), developed originally for perfluoroalkylsulfonic acid (PFSA) membranes, and the high relative humidity AST (80 °C, 100% RH, H₂/O₂, 2.5 bar_a), designed for aromatic hydrocarbon membranes. We found that doping the grafted membranes with a metalated porphyrin antioxidant can simultaneously reduce membrane aging and improve fuel cell performance. Full article

Monodisperse Pt nanoparticles supported on carbon (Pt/C) were prepared via an impregnation method. By changing the concentration of the platinum precursor in the initial reagent mixture, the average particle size (d) could be controlled to within a narrow range of less than 2 nm. The specific activity (SA) of these materials, when applied to the oxygen reduction reaction (ORR), increased rapidly with d in the range below 1.8 nm, with a maximum SA at d = 1.3 nm. This value is approximately four times that of a commercial Pt/CB catalyst. The electrochemical active area, ECAA (electrochemical surface area (ECSA)/specific surface area (SSA) × 100), decreased drastically from 100% with decreases in d below 1.3 nm. In this study, we present a correlation between SA and ECAA as a means of determining the appropriate d for polymer electrolyte fuel cells (PEFCs) and propose an optimal size. Full article

The shelf-life of catalyst ink for fabricating polymer electrolyte fuel cells (PEFCs) is relevant for large-scale manufacturing with unforeseen production stops. In this study, the storage effects on the physicochemical characteristics of catalyst ink (Pt/C, Nafion, 2-propanol, water) and subsequently manufactured catalyst layers are investigated. Sedimentation analysis showed that catalyst particles are not fully stabilized by charge interaction induced by Nafion. Acetone was found to be an oxidation product, even in freshly prepared ink with platinum catalyzing the reaction. Rotating disk electrode analysis revealed that the electrochemically active surface area is, overall, minimally increased by storage, and the selectivity towards water formation (4-electron pathway) is unharmed within the first 48 h of storage. MEAs prepared from stored ink reach almost the same current density level after conditioning via potential cycling. The open-circuit voltage (OCV) increases due to increased catalyst availability. Scanning electron microscopy and mercury intrusion porosimetry showed that with increasing acetone content, the pore structure becomes finer, with a higher specific surface area. Electrochemical impedance spectroscopy revealed that this results in a more hindered mass transfer but lowered charge transfer resistance. The MEA with the highest OCV and power output and the lowest overall cell resistance was fabricated from catalyst ink stored for a duration of four weeks. Full article

Compton scattering imaging with intense, high-energy synchrotron X-rays allows us to visualize a light element substance in an operating electrochemical device. In this paper, we report the first experiment of Compton scattering imaging (CSI) on an operating polymer electrolyte fuel cell (PEFC). The novelty of the CSI technique is a non-destructive direct observation of cross-sectional images with a sensitivity to light elements and a capability of simultaneous measurements with fluorescent X-rays of heavy elements. Analyses of the observed images provide the cross-sectional distribution of generated liquid water and its current density dependency. The results show that the amount of generated water increases in the vicinity of the cathode catalyst layer at current densities ranging from 100 to 500 mA/cm², while it remains constant or slightly decreases from 500 to 900 mA/cm². In both the gas diffusion layer and the channel, liquid water is observed near the channel and rib interface above 500 mA/cm², indicating the formation of a liquid water flow path. In addition, simultaneous measurements of fluorescent Pt-Ka X-rays reveal a significant correlation between the generated liquid water and Pt catalysts, using the Pearson correlation coefficient. The result shows that water is dispersed in the catalyst layer without any correlation with the amount of Pt catalysts at low current densities, but water tends to be distributed in the Pt-rich areas at high current densities. This study demonstrates that Compton scattering imaging is one of the unique techniques to characterize the behavior of generated liquid water in an operating PEFC. Full article

A new three-dimensional numerical model of a polymer electrolyte fuel cell (PEFC) with a single straight channel was developed to primarily investigate the important impact of the double-sided microporous layer (MPL) coating on the overall performance of the fuel cell and the distribution of the current and the oxygen concentration within the cathode gas diffusion layers (GDLs). Realistic experimentally estimated interfacial contact resistance values between the gas diffusion layer and each of the bipolar plates and the catalyst layer values were incorporated into the model, and parametric studies were performed. The results showed that the double-sided MPL coating could significantly improve the fuel cell performance by up to 30%. Additionally, it was shown that the neglect of the contact resistance between the MPL and the catalyst layer could overestimate the fuel cell performance by up to 6%. In addition, the results showed that the fuel cell performance and the distribution of the current and oxygen are more sensitive to the porosity of the MPL facing the bipolar plate than the porosity of the MPL facing the catalyst layer. All the above results are presented and critically discussed in detail. Full article

A new method for measuring membrane degradation in polymer electrolyte fuel cells (PEFCs) is proposed. The method is based on the detection of fluoride ions in effluent water from the cathode- and anode outlet of the PEFC using photometry (PM). The fluoride emission rate (FER) is an indicator of the membrane’s state of health (SoH) and can be used to measure the chemical membrane degradation. Commercial catalyst-coated membranes (CCMs) have been tested at 80 °C and 90 °C at 30% relative humidity (RH) to investigate the reliability of the developed method for fuel cell effluent samples. To verify the measurement, a mean-difference plot was created by measuring the same data with a fluorine selective electrode. The average difference was at ±0.13 nmol h⁻¹ cm⁻², which indicates good agreement between the two methods. These new findings imply that PM is a promising method for quick and simple assessment of membrane degradation in PEM technology. Full article

In hydrogen energy systems, the polymer electrolyte fuel cell (PEFC) is an important component. The purpose of this study is to clarify the effect of separator thickness (s.t.) in PEFC on the distributions of mass such as H₂, O₂, H₂O and current density when PEFC is operated at 363 K and 373 K. The relative humidity (RH) of supply gases also impacts the operation. The numerical simulation (using a 3D model) with COMSOL Multiphysics has been conducted to analyze the characteristics of PEFC. It has been observed that the molar concentration of H₂ using s.t. of 2.0 mm is smaller compared with the thinner s.t. cases at the initial operation temperature of a cell (T_ini) = 363 K and 373 K. The molar concentration of O₂ using s.t. of 2.0 mm is smaller compared with the thinner s.t. cases at T_ini = 373 K, as well as the case for the RH of supply gases at the anode of 40%RH and cathode of 40%RH (A40%RH/C40%RH) irrespective of T_ini. Additionally, it has been clarified that the molar concentration of H₂O maintains a low value along with the gas channel at T_ini = 373 K using s.t. of 1.5 mm and 1.0 mm. Moreover, it has been clarified that the current density using s.t. of 2.0 mm is the highest among the different s.t. irrespective of T_ini, which is the most remarkable in the case of A40%RH&C40%RH. Full article

We evaluated the power generation characteristics of a polymer electrolyte fuel cell (PEFC) composed of Pt-supported carbon nanowalls (CNWs) and a microporous layer (MPL) of carbon black on carbon paper (CP) as catalyst support materials. CNWs, standing vertically on highly crystallizing graphene sheets, were synthesized on an MPL/CP by plasma-enhanced chemical vapor deposition (PECVD) using inductively coupled plasma (ICP). Pt nanoparticles were supported on the CNW surface using the liquid-phase reduction method. The three types of voltage loss, namely those due to activated polarization, resistance polarization, and diffusion polarization, are discussed for the power generation characteristics of the PEFC using the Pt/CNWs/MPL/CP. The relationship between the height or gap area of the CNWs and the voltage loss of the PEFC is demonstrated, whereby the CNW height increased with the extension of growth time. The three-phase interface area increased with the increase in the CNW height, resulting in mitigation of the loss due to activated polarization. The gap area of the CNWs varied when changing the CH₄/H₂ gas ratio. The loss due to diffusion polarization was reduced by enlarging the gap area, due to the increased diffusion of fuel gas and discharge of water. The secondary growth of the CNWs caused the three-phase interface area to decrease as a result of platinum aggregation, impedance of the supply of ionomer dispersion solution to the bottom of the CNWs, and inhibition of fuel gas and water diffusion, which led to the loss of activated and diffuse polarizations. The voltage losses can be mitigated by increasing the height of CNWs while avoiding secondary growth. Full article

The aim of this study is to clarify the impact of the thickness of a gas diffusion layer (GDL) and a micro porous layer (MPL) on the distributions of gas, H₂O, and current density in a polymer electrolyte fuel cell (PEFC) which is operated at 363 K and 373 K and with various thicknesses of polymer electrolyte membrane (PEM) as well as a relative humidity (RH) of supply gas. These investigations are carried out by numerical simulation using the 3D model with COMSOL Multiphysics. In the case of Nafion 115, which is the thicker PEM, the change in the molar concentration of H₂O from the inlet to the outlet with MPL is larger than that without MPL irrespective of the thickness of GDL, T_ini and RH condition. In the case of Nafion NRE-212, which is the thinner PEM, the change in the molar concentration of H₂O from the inlet to the outlet is larger with MPL than that without MPL in the case of TGP-H-060 (the thicker commercial GDL), while that is smaller with MPL than that without MPL in the case of TGP-H-030 (the thinner commercial GDL). These results exhibit the same tendency as the results of the numerical simulation on the current density. Full article

The New Energy and Industry Technology Development Organization (NEDO) road map (Japan, 2017) has proposed that a polymer electrolyte fuel cell (PEFC) system, which operates at a temperature of 90 °C and 100 °C, be applied for stationary and mobility usage, respectively. This study suggests using a thin polymer electrolyte membrane (PEM) and a thin gas diffusion layer (GDL), at the same time, to achieve better power-generation performance, at a higher temperature than usual. The focus of this paper is to clarify the effect of separator thickness on the distribution of temperature at the reaction surface (T_react), with the relative humidity (RH) of the supply gasses and initial operation temperature (T_ini), quantitatively. In this study, separator thickness is investigated in a system using a thin PEM and a thin GDL. Moreover, this study investigates the difference between the maximum temperature and the minimum temperature obtained from the distribution of T_react as well as the relation between the standard deviation of T_react − T_ini and total voltage, to clarify the effect of separator thickness. The impact of the flow rates of the supply gases on the distribution of T_react is not large, among the investigated conditions. It is noticed that the temperature distribution is wider when a separator thickness of 2.0 mm is selected. On the other hand, it is observed that the temperature increases along with the gas flow through the gas channel, by approximately 2 °C, when using a separator thickness between 1.5 mm and 1.0 mm. The impact of the RH on the distributions of T_react − T_ini is larger at T_ini = 100 °C, when a separator thickness of 1.0 mm is selected. It is revealed that the wider temperature distribution provides a reduction in power-generation performance. This study proposes that the thin separators, i.e., with a thickness of 1.5 mm and 1.0 mm, are not suitable for higher temperature operation than usual. Full article

Optimization of the structure of cathode catalyst layers (CCLs) for promoting the transfer of reactants and products in polymer electrolyte fuel cells (PEFCs) is important for improving the cell performance. In this study, using theoretical equations, we confirmed that the shortened proton conduction path in the ionomer layer (IL) with a 3D-patterned structure, compared to that in the IL with a flat-patterned structure, can improve the cell performance. We experimentally investigated the effect of the IL with a 3D-patterned structure included in the CCLs on the cell performance. Based on the combination of the flat- or 3D-pattern of the IL and the catalyst layer (CL), the samples were categorized as Str. 1 (3D-patterned CL without IL), Str. 2 (flat-patterned IL and CL), Str. 3 (3D-patterned IL and flat-patterned CL), and Str. 4 (3D-patterned IL and CL). All of the samples had different morphologies. According to the I–V curves and impedance spectra data acquired at 80 °C and 40% relative humidity, Str. 4 showed superior cell performance relative to those of the other CCLs. These results indicate that the structure of Str. 4 enhanced the proton conductivity at a low humidity at which proton conduction is usually poor, thereby resulting in improved cell performance. Full article

In this report, a 5 kW PEFC system running on dry hydrogen with an appropriately sized Balance of Plant (BoP) was used to conduct experimental studies and analyses of gas supply subsystems. The improper rating and use of BoP components has been found to increase parasitic loads, which consequently has a direct effect on the polymer electrolyte fuel cell (PEFC) system efficiency. Therefore, the minimisation of parasitic loads while maintaining desired performance is crucial. Nevertheless, little has been found in the literature regarding experimental work on large stacks and BoP, with the majority of papers concentrating on modelling. A particular interest of our study was the anode side of the fuel cell. Additionally the rationale behind the use of hydrogen anode recirculation was scrutinised, and a novel anode purging strategy was developed and implemented. Through experimental modelling, the use of cathode air blower was minimised since it was found to be the biggest contributor to the parasitic loads. Full article

In this study, we investigated the effect of silica (SiO₂) layer included in a cathode catalyst layer (CL) on the performance for polymer electrolyte fuel cells (PEFCs). Porous carbons such as Ketjen black (KB) have been widely used as a support for Pt catalysts in PEFCs. Such KB-supported Pt catalyst (Pt/KB) was used as a cathode CL with low ionomer content (a condition of low proton conductivity). The Pt/KB was then coated with SiO₂. In addition, the Pt/KB and SiO₂-coated Pt/KB (SiO₂-Pt/KB) were measured and analyzed under relative humidity (RH) conditions (100% and 20%). The catalyst ink of SiO₂-Pt/KB showed higher stability and dispersion compared to Pt/KB, due to the hydrophilic surface characteristics of SiO₂, which act as a binder-like ionomer. The performance of the SiO₂-Pt/KB at 100% RH, was significantly lower than that of Pt/KB, whereas the performance of the Pt/KB at 20% RH, was significantly improved by SiO₂ coating. This is due to an increase in the proton conductivity, which can be attributed to the hydrophilic properties of SiO₂. Based on these results, the effect of SiO₂ coating on performance, depending on carbon supports of SiO₂-coated Pt/Carbon catalysts, could be evaluated. Full article

The development of green energy conversion devices has been promising to face climate change and global warming challenges over the last few years. Energy applications require a confident performance prediction, especially in polymer electrolyte fuel cell (PEFC), to guarantee optimal operation. Several researchers have employed optimization algorithms (OAs) to identify operating parameters to improve the PEFC performance. In the current study, several nature-based OAs have been performed to compute the optimal parameters used to describe the polarization curves in a PEFC. Different relative humidity (RH) values, one of the most influential variables on PEFC performance, have been considered. To develop this study, experimental data have been collected from a lab-scale fuel cell test system establishing different RH percentages, from 18 to 100%. OAs like neural network algorithm (NNA), improved grey-wolf optimizer (I-GWO), ant lion optimizer (ALO), bird swarm algorithm (BSA), and multi-verse optimization (MVO) were evaluated and compared using statistical parameters as training error and time. Results gave enough information to conclude that NNA had better performance and showed better results over other highlighted OAs. Finally, it was found that sparsity and noise are more present at lower relative humidity values. At low RH, a PEFC operates under critical conditions, affecting the fitting on OAs. Full article