ABSTRACT The present investigation evaluates the usability of Gd and Nd co‐doped CeO 2 (0.05Gd 0.05Nd) and CeO 2 (0.05Gd 0.05Nd) + SrTiO 3 (60:40) composite synthesized by glycine combustion as electrolytes in medium‐temperature solid oxide fuel cells (SOFCs) through a comprehensive analysis of their ionic conductivity and structural characteristics. The crystal structure and phase analyses of the materials were characterized by x‐ray diffraction (XRD), and it was confirmed that both samples successfully formed the targeted cubic fluorite (CeO 2 ) and perovskite (SrTiO 3 ) phases, and the dopant elements were integrated into the main lattice. Raman spectroscopy was used to study the effect of doping elements on the lattice dynamics and oxygen vacancies. FESEM (field emission scanning electron microscopy) analyses demonstrated that the addition of SrTiO 3 reduced the grain size from 90.45 to 33.39 nm, leading to a more homogeneous and compact microstructure. Conductivity and activation energy were assessed using electrochemical impedance spectroscopy within the temperature range of 400–550°C. In this study, it was observed that the total conductivity values of the prepared materials measured under air atmosphere are higher than the typical values reported in the literature for SOFC electrolytes. This suggests that the conduction cannot be explained solely by oxygen ion transport and may indicate the presence of a possible mixed conduction mechanism in which both ionic and electronic charge carriers are involved. In this context, the obtained findings indicate that the studied system may be considered a potential candidate as a mixed‐conducting electrode material for intermediate‐temperature SOFCs.

ABSTRACT The present work on a novel electro‐mechanical agitation‐based nanocomposite bioanode has been developed to be used in the performance‐based enzymatic biofuel cells (EBFCs). This nanocomposite incorporates zinc‐blende nanodots (ZBNDs), silver nanostrands (AgNS), multiwalled carbon nanotubes (MCNTs), as well as polyaniline (PANi), which is prepared by a green route using a neem ( Azadirachta indica ) leaf extract as the reducing and stabilizing agent. During synthesis, uniform dispersion and controlled formation of nanostructures and increased interfacial synergy among components were made possible by electro‐mechanical agitation, which increased enzyme immobilization and electron transfer. The study methodically assesses the structural features, catalytic performance, stability of operations, and usability of the synthesized nanocomposite. The material was thoroughly characterized by material characterization (FTIR, XRD, EDX, SEM, and TEM) that indicated the creation of a porous, conductive structure, with the electrochemical analysis (CV, EIS, LSV) revealing a maximum current density of 8.56 mA/cm 2 and a power output of 320 mW/cm 2 which was higher than the majority of conventional EBFC bioanodes. There was also great reproducibility and long‐term stability in the use of the bioanode. It is a new synthesis pathway, a synthesis involving agitation‐assisted dispersion of a rarely studied strategy in conductive polymer nanocomposites using green chemistry. The developed bioanode has two potential applications in sustainable energy and biomedical technologies, and in addition to energy harvesting, it can be used in self‐powered biosensing devices.

ABSTRACT Green energy and renewable energy sources (RESs) are between the most important topics in power, energy, and transportation and are crucial for sustainability for next generations. When a hydrogen fuel cell or solar array is used for the electric vehicle (EV), the next step is using an efficient, high power, and simple structure based power electronics converter to storage the energy of these RESs into the battery pack. The integration of artificial intelligence into the control and optimization of DC–DC power converters presents promising opportunities in improving energy management and efficiency in EV sector. This study presents a low‐input current and low voltage stress topology for application in fuel cell to battery charging systems in EVs. A current filter by forming a switched inductor cell at the input side of the converter guarantees a small ripple for input sources that enhances the longevity and long‐life of the FC stacks or solar panels. The application of the switched capacitor circuits at the input and end sides of the converter decreases the voltage stress across the semiconductor devices and enhances the mean time to failure rate of the converter that is between the most important features of a converter. The presented topology enhances the input voltage to 7 and 19 times for duty ratios equal to 0.5 and 0.8, respectively, while the switch experiences three and nine times the input voltage for the same duty ratios, which is considerable. The configuration of the diodes and capacitors in the switched capacitor, by dividing the total voltage stress, results in impressively low voltage ripples. This converter includes one power switch, which minimizes the complexity of the controller and enhances the feasibility. The converter design incorporates a three‐layer, three‐input artificial neural network structure. The regression values were 0.982 for training, 0.983 for testing, and 0.9827 overall, indicating minimal prediction error and confirming the effective training of the neural network model. The laboratory test results for power levels around 200 W have been presented and confirm the correctness of the proposed algorithm and the application of the proposed converter. To obtain 0.5 A for the load under a 350 VDC output voltage, the input source presents an average current equal to 8 A, and the switch experiences around 160 V voltage stress across the drain–source pins. Results show that Inductor L 2 has lower current stress than Inductor L 1 .

ABSTRACT Protonic ceramic fuel cells (PCFCs) have high energy conversion efficiencies and can be employed as next‐generation fuel cells. However, novel cathode materials with high electrochemical performances at low operating temperatures are required to practically apply PCFCs. BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3– δ (BCFZrY) is a promising material for PCFC cathodes owing to its low electrode polarization resistance ( R p ). Herein, instead of Zr doping, BaCo 0.4 Fe 0.4 A 0.1 Y 0.1 O 3– δ (BCF A Y) compounds, where A represents Ti, Mg, or Zn, were evaluated as PCFC cathode materials. BCF A Y ( A : Ti, Mg, or Zn) compounds have a higher oxygen permeability than BCFZrY. The electrochemical properties and power generation performance of the PCFCs with BCF A Y cathodes were measured and compared with those of PCFCs with BCFZrY cathodes. The PCFC with a BCFMgY cathode exhibited the lowest R p , leading to the highest power density, that is, 0.80 W cm −2 at 600°C. In addition, for all PCFCs with BCFY‐based cathodes, the reciprocal area‐specific resistances of R p and oxygen permeability fluxes of the cathode materials had an approximately proportional relationship. Therefore, it was confirmed that PCFC cathodes with a high oxygen permeability had a low cathode polarization resistance, which significantly enhanced the power generation performance of PCFCs.

ABSTRACT Fuel Cell Electric Vehicles (FCEVs) require more capable influence on adaptation schemes to ensure smooth operation and maximum energy utilization. Strong Maximum Power Point Tracking (MPPT) in the systems is challenging due to the fuel cell nonlinearity, dynamic loads, and fluctuating ambient conditions. Conventional MPPT methods are marred by slow convergence, local optimum trapping, and poor tracking of sudden transients. To eliminate these limitations, this manuscript presented a high‐gain interleaved DC–DC converter (HGIDCDCC)‐based optimum MPPT control method with the Starfish Optimization Algorithm (SFOA) and Putterfish Algorithm (PFA). The method benefits from the high voltage gain (VG) and ripple rejection of the interleaved converter, while SFOA–PFA hybrid optimization improves the MPPT displays in terms of higher convergence rate, global search ability, and steady‐state stability. The designed converter structure and MPPT controller enhance the power conversion efficiency, voltage regulation, fuel cell temperature change response, and output power in all validated environments. In addition to FCEVs, the approach is also supportive of hybrid renewable power and storage systems, in which stable voltage, efficiency, and reliability are essential. The accuracy of the proposed approach is 99%.

ABSTRACT The global demand for proton exchange membrane fuel cells (PEMFCs) is rapidly increasing due to their high efficiency, zero carbon emissions, and potential for sustainable energy conversion in transportation and power systems. Compared to internal combustion engines, gas engines, and turbine systems, PEMFCs demonstrate superior energy efficiency. However, achieving consistent and sustainable efficiency remains a key research challenge, driving numerous ongoing investigations. One crucial factor affecting PEMFC performance is heat management, as it significantly influences microscopic and macroscopic particle behavior near and surface of electrode. The present study focuses on analyzing the scattering dynamics of charge particle on the electrode surface (thermal electron) due to surrounding particles (thermal hydrogen) and their impact on PEMFC performance. The research comprises both theoretical and experimental approaches. Theoretically, a relationship was developed between the differential cross‐section (DCS) and various PEMFC parameters, whereas the experimental work aimed to verify the proposed model. The results indicate that DCS decreases with increasing current density, whereas temperature rises with increasing output current. DCS also decreases with the scattering angle, reaches a minimum, and then increases again at different output voltages and efficiencies. Similarly, DCS increases with incident electron energy, attains a maximum, and then decreases as the energy continues to rise. In regions of smaller separation, DCS increases with separation at different voltages and efficiencies. Experimental results confirm that rising temperature reduces the cell's output voltage, verifying the theoretical inverse relationship between DCS and voltage. These findings contribute to enhancing PEMFC performance, supporting the application of advanced technologies such as scanning tunneling microscopy, laser‐induced fluorescence, quantum computing, and nanophotonic sensors for improved efficiency and control.

ABSTRACT Microbial fuel cells (MFC) are gaining popularity as energy solutions because they harness microbial metabolism to transform organic materials directly into electricity. Membrane‐less MFC serve as an alternative to traditional membrane‐based systems, providing benefits like reduced cost, simplified design, minimized fouling, and improved scalability. However, the lack of a membrane in membrane‐less MFC could lead to short‐circuiting of electrochemical reactions along with instability of microbial community over time, resulting in instability, low power production, and decreased efficiency. To improve their performance and long‐term stability, reactor designs and microbial‐electrode interactions must be improved. This review article delivers a thorough analysis of the latest developments, challenges, and applications of electrogenic bacteria within anodic biofilms for energy generation in MFC. It highlights the potential of membrane‐less MFC in advancing this technology by exploring key aspects such as design principles, strategies for improving performance, viable organic substrates, and future outlooks.

ABSTRACT This study employs an integrated approach combining three‐dimensional multiphase numerical simulations with experimental validation. A refined single‐channel proton exchange membrane fuel cell (PEMFC) model, verified for grid independence, was developed. User‐defined functions (UDFs) were implemented to accurately describe key processes, including electrochemical reactions, water phase change (liquid/ice), and transport phenomena. A systematic simulation analysis was conducted to elucidate the influence of operating temperature (50–70°C), anode/cathode inlet humidity (50–100% relative humidity), and gas diffusion layer (GDL) porosity (0.4–0.8) on cell output characteristics (polarization curves, power density) and internal mass transport dynamics. Concurrently, cyclic voltammetry (CV) and linear sweep voltammetry (LSV) experiments were performed to deeply investigate the electrochemical performance degradation and microstructural evolution of electrodes with varying water contents under freeze–thaw cycling. The results demonstrate that elevating the operating temperature to 60–70°C significantly enhances cell performance, primarily attributable to increased membrane conductivity and optimized water management. A synergistic optimization effect was identified between reactant gas humidity and GDL porosity. At 60°C, a combination of 75% anode humidity and 100% cathode humidity achieved an optimal balance between output performance and operational stability. Increasing GDL porosity to 0.6–0.8 effectively enhanced reactant gas transport and liquid water removal, reducing current density decay during cold start (−10°C) by approximately 50% and significantly mitigating mass transport blockage and performance degradation caused by ice formation. Freeze–thaw cycling experiments further revealed that electrode water content is a critical factor determining its durability. Flooded conditions exacerbated structural damage from freezing, leading to persistent performance decay, whereas lower water content conditions effectively preserved electrode structural integrity and catalytic activity. This research elucidates the interactive mechanisms of water–thermal–mass transport under multiphysics coupling, providing a theoretical foundation and practical design guidelines for optimizing performance and enhancing the durability of PEMFCs under complex operating conditions.

ABSTRACTIn the present study, a strongly coupled three‐dimensional thermal‐electric‐fluid‐mass model was developed, and the thermal‐electric performance of the solid oxide fuel cell (SOFC) with a zigzag channel under various operating conditions was analyzed. The results indicated that increasing the operating temperature and the anode inlet Reynolds number could enhance the output power density of the SOFC, whereas the temperature gradient within the SOFC also increased accordingly. The enhancement of these parameters led to an increase in the electrical performance (characterized by power density) of the SOFC while concurrently diminishing its thermal performance (characterized by temperature gradient). Under the same conditions, the SOFC with a zigzag channel exhibited superior electrical performance compared to the SOFC with a conventional parallel channel, albeit with slightly inferior thermal performance. Keeping the flow parameters constant (Re = 1.0) and the temperature maintained at 1123 K, the electrical performance of the SOFC with a zigzag channel was 8.6% higher than that of the SOFC with a parallel channel, whereas the thermal performance was 4.2% lower. Keeping the temperature parameter constant (T = 1073 K) and the anode inlet Reynolds number maintained at 1.7, the output power density of the SOFC with a zigzag channel was 5.9% higher than that of the SOFC with a parallel channel, whereas the temperature uniformity was 2.6% lower. The issue of internal temperature non‐uniformity caused by the zigzag channel design of the SOFC could be balanced by adopting the co‐flow operation condition. At a working temperature and flow condition of T = 1073 K and Re = 1.0, the thermal performance of the SOFC with a zigzag channel in a co‐flow configuration was 5% higher than that in a counter‐flow configuration, whereas its electrical performance decreased by only 0.2% compared to the counter‐flow configuration.

ABSTRACTA growing interest in operating proton exchange membrane fuel cells at intermediate temperatures (80°C–120°C) has emerged due to the aim of implementing fuel cells in demanding applications like aviation and heavy‐duty automotive uses. Operating at intermediate temperatures has several advantages, such as reduced cooling demand and increased kinetics. This is particularly important for applications that frequently experience high‐load conditions, where power usage and heat production are high. However, the impact of these temperatures on the degradation of membrane electrode assemblies (MEAs) is not well understood. Here, we show performance degradation of four automotive type MEAs at 80°C, 100°C, and 120°C, studied using electrochemical characterization and electron microscopy. Higher operating temperatures leads to increased performance degradation, increased Pt growth and larger electrochemical surface area (ECSA) losses for all samples. However, neither ECSA losses nor increased resistance are sufficient to explain the severe performance loss observed for most samples at 120°C. These results highlight the importance of optimizing catalyst layers for specific operation conditions and show that the cathodic catalyst layer has a large impact on the increased degradation at intermediate‐temperature operation. This study helps to understand the effects of intermediate temperature operation on the catalyst layer.