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A facile method is proposed in this work to prepare a carbon paper (CP) with outstanding properties by doping boron to catalyze graphitization at lower temperature. Boron was introduced into CP by impregnating carbon fiber preform into a boron/phenolic resin/ethanol solution, and then CP was obtained after the consecutive procedures of hot pressing, carbonization, and graphitization. Morphology, microstructure, composition, and physical properties of the doped and undoped CPs were thoroughly investigated via various techniques to exam the effects of boron concentration and graphitization temperature. Furthermore, the boron doped CP was fabricated into fuel cell gas diffusion layer (GDL) and membrane electrode assembly (MEA) to evaluate its performance through the single cell performance. The findings indicated CP doping with 2 wt% boron could lower the graphitization temperature by at least 200 °C. The B-doped GDL had a higher power density in comparison with the undoped GDLs made in our lab or from the commercial brands. • The innovative preparation method for carbon paper with high conductivity. • The effect of boron concentration and graphitization temperature on carbon paper. • The single cell performance of B-doped gas diffusion layer. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cells (SOFCs) can accept a direct feed of biogas for power generation; however, carbon deposition is a major obstacle to their practical application. When a paper‐structured catalyst (PSC) with a dispersion of Ni‐loaded flowerlike Ce0.5Zr0.5O2 (Ni/CZ(F)) was applied to the anode of an electrolyte‐supported cell (ESC), the open‐circuit voltage of the cell directly fed simulated biogas was increased from 0.87 to 0.98 V at 750°C. The rates of cell‐voltage degradation and coke formation of the ESC with the Ni/CZ(F)‐PSC during 100 h of operation were 4.3% kh−1 and 0.43 mg‐C g‐PSC−1 h−1, respectively, which were lower than those of an ESC with a Ni‐loaded PSC without the CZ(F) dispersion (10.4% kh−1 and 8.1 mg‐C g‐PSC−1 h−1, respectively). This performance improvement is attributed to the unique porous morphology and high oxygen storage capacity of CZ(F), which can contribute to the prevention of Ni agglomeration and the removal of coke from the catalyst surface, respectively. Thus, the Ni/CZ(F)‐PSC can function as a practically applicable reforming domain for an internal‐reforming biogas‐fueled SOFC. [ABSTRACT FROM AUTHOR]

Protonic solid oxide fuel cells (P–SOFCs) is an active field in development of intermediate-temperature fuel cells to render high power density and durability. The use of pulsed laser deposition (PLD) to deposit the functional layers and interlayers of P–SOFCs supported on anode substrates offers advantages in reducing both the ohmic and polarization resistances of the cell, which however critically depends on the substrate microstructure. Here we use ashless paper fibers as pore former mixed with NiO and BaCe 0.7 Zr 0.1 Y 0.1 Yb 0.1 O 3-δ (BCZYYb) powders to prepare anode substrates with large, interconnected cylindrical pores, followed by using electrophoretic deposition to deposit NiO-BCZYYb as pore filler to fill the pores exposed on the top surface. With an anode substrate made using 20 wt% paper fiber and PLD-deposited NiO-BCZYYb anode functional layer (AFL), NiO-BCZYYb anode interlayer, and BCZYYb electrolyte layer, the peak power density reaches 550 mW/cm2 at 600 °C, which is 30 % higher than that of the cell with a commercial half-cell composed of NiO-BCZYYb substrate and spin-coated BCZYYb electrolyte layer but the same cathode interlayer and cathode layer. Furthermore, the insertion of a PLD-deposited graded anode interlayer between the AFL and electrolyte layer is found to be critical for high cell durability. [Display omitted] • Ashless paper fiber is used as pore former in fabricating P–SOFC anode substrate. • Paper fiber produces long, thick interconnected pores with higher gas permeability. • Electrophoretic deposition of pore filler effectively fills exposed surface pores. • Graded anode interlayer deposited by pulsed laser deposition raises cell durability. • Cell with 20 wt% paper fiber exhibits the highest cell power density. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cells (SOFCs) are vital for alternative energy, powering motors effi-ciently. They offer fuel versatility and waste heat recovery, making them ideal for various applications. Optimizing interconnector structures is crucial for SOFC advancement. This paper introduces a novel 2D simulation model for interconnector SOFCs, aiming to enhance their performance. We initially construct a single half-cell model for a conventional interconnector SOFC, ensuring model accuracy. Subsequently, we propose an innovative interconnector SOFC model, which outperforms the conventional counterpart in various aspects. [ABSTRACT FROM AUTHOR]

Degradation is an inevitable companion in the operation of solid oxide fuel cell (SOFC) systems since it directly deteriorates the reliability of the system's operation and the system's durability. Both are seen as barriers that limit the extensive commercial use of SOFC systems. Therefore, diagnosis and prognosis are valuable tools that can contribute to raising the reliability of the system operation, efficient health management, increased durability and implementation of predictive maintenance techniques. Remaining useful life (RUL) prediction has been extensively studied in many areas like batteries and proton-exchange membrane fuel cell (PEM) systems, and a range of different approaches has been proposed. On the other hand, results available in the domain of SOFC systems are still relatively limited. Moreover, methods relying on detailed process models and models of degradation turned out to have limited applicability for in-field applications. Therefore, in this paper, we propose an effective, data-driven approach to predicting RUL where the trend of the health index is modeled by an adaptive linear model, which is updated at all times during the system operation. This allows for a closed-form solution of the probability distribution of the RUL, which is the main novelty of this paper. Such a solution requires no computational load and is as such very convenient for the application in ordinary low-cost control systems. The performance of the approach is demonstrated first on the simulated case studies and then on the data obtained from a long-term experiment on a laboratory SOFC system. From the tests conducted so far, it turns out that the quality of the RUL prediction is usually rather low at the beginning of the system operation, but then gradually improves while the system is approaching the end-of-life (EOL), making it a viable tool for prognosis. [ABSTRACT FROM AUTHOR]

This paper presents an overview of the status and future prospects of fuel-cell electric vehicles (FC-EVs). As global concerns about emissions escalate, FC-EVs have emerged as a promising substitute for traditional internal combustion engine vehicles. This paper discusses the fundamentals of fuel-cell technology considering the major types of fuel cells that have been researched and delves into the most suitable fuel cells for FC-EV applications, including comparisons with mainstream vehicle technologies. The present state of FC-EVs, ongoing research, and the challenges and opportunities that need to be accounted for are discussed. Furthermore, the comparison between promising proton-exchange membrane fuel cell (PEMFC) and solid oxide fuel cell (SOFC) technologies used in EVs provides valuable insights into their respective strengths and challenges. By synthesizing these aspects, the paper aims to provide a comprehensive understanding and facilitate decision-making for future advancements in sustainable FC-EV transportation, thereby contributing to the realization of a cleaner, greener, and more environmentally friendly future. [ABSTRACT FROM AUTHOR]

A solid oxide fuel cell (SOFC) is regarded as the first choice of high-efficiency and clean power generation technology in the 21st century due to its characteristics of high power generation efficiency and low pollutant emission. In this paper, hydrogen is used as a fuel for SOFCs using the EBSILON platform. A sensitivity analysis of the solid oxide fuel cell-gas turbine (SOFC-GT) system with steam reinjection is carried out to investigate the effect of the steam reinjection mass flow rate on the improvement of the electrical efficiency of the system and on the values of the other parameters. The results show that the variation in the steam reinjection mass flow rate has an effect on other parameters. Changes in several parameters affect the electrical efficiency of the system, which reaches 74.11% at a pressure ratio of 10, SOFC inlet temperature of 783.15 K, turbine back pressure of 70 kPa, and steam reinjection mass flow rate of 6.16 kg/s. Future research can optimize the overall parameter selection of the system in terms of economy and other aspects. [ABSTRACT FROM AUTHOR]

Spray pyrolysis technique has been applied to deposit a broad range of thin films, which are used in various devices such as solar cells, sensors, and solid oxide fuel cells. Spray pyrolysis is one of the most common, inexpensive, simple, and quite versatile methods used for synthesizing submicron and sphericalshaped luminescent materials multicomponent oxide thin films. In this paper, spray pyrolysis TiO2 thin films has been deposited on glass substrates and kept at different temperature to reveal its optical properties by the help of UV-visible spectroscopy. Refractive index (n) of TiO2 thin films as wide semiconductor has been calculated using optical energy gap (Eg). The calculated values of refractive index from the new relations have been compared with the values reported by different researchers; an excellent agreement has been obtained between them. The material identification was confirmed from X-ray diffraction techniques and first derivative of transmission spectra’s has been plotted that gives band gap value of films respectively. [ABSTRACT FROM AUTHOR]

Aiming at the solid oxide fuel cell (SOFC) applied to the ship DC microgrid in the face of pulse load disturbance is prone to make the SOFC voltage drop too large leading to the DC grid oscillation problem. In this paper, a stability criterion method for SOFC-Li battery DC system based on hybrid potential function is proposed. Firstly, a mathematical model of shipboard DC microgrid with SOFC-Li battery is established and the accuracy of the model is verified. Then, the stability criterion of the system based on the hybrid potential function under large disturbances is constructed. Subsequently, the effects of system stability under impulse load conditions were analysed under different parameters. Based on the constructed criterion, simulation verification of the stability boundary conditions of the SOFC system operating independently or jointly with a lithium battery system is carried out. The experimental results show that the proposed stability criterion and control strategy are effective in accurately predicting the system stability boundary. The experimental results verify the effectiveness of the proposed method in improving the stability of the system and provide a theoretical basis for further research on the dynamic characteristics of SOFC systems under complex load conditions. [ABSTRACT FROM AUTHOR]

Developing high-efficiency and low-carbon propulsion systems is a pressing concern within the aviation field. This paper studies a hybrid power system that combines a solid oxide fuel cell and a gas turbine (SOFC-GT) with propane as fuel, which is easy to store and has a high energy density. The analysis focuses on key parameters such as compressor pressure ratio, fuel utilization rate, and fuel distribution. And a balance between system efficiency and the power-to-weight ratio has been achieved through multi-objective optimization. The conclusions indicate that system efficiency and system weight in the hybrid power system are optimized in opposite directions. Within the design parameters, the hybrid power system's efficiency achieves 0.621, the specific fuel consumption is 115.2 g/kWh, and the power-to-weight ratio is 0.569 kW/kg. Further discussion on the application of this hybrid system in long-endurance unmanned aerial vehicles shows an efficiency of 0.651 during the cruise phase, indicating a promising application prospect of a propane-fueled SOFC-GT hybrid system in the aviation field. [ABSTRACT FROM AUTHOR]

Global warming is a vital problem that many researchers tried to solve with so many solutions such as: reducing electricity production with conventional generators by using renewable energy resources and using hydrogen as an alternative to fossil fuels. The universal Economic crisis came across to cut off certain quantities at scheduled times. This, directly, affects renewable energy sources connected to the grid due to voltage and frequency variations. To solve this dilemma, in this paper, the grid-connected solid oxide fuel cell (SOFC) model which is fed by green hydrogen to produce AC power, is developed by an Adaptive neuro-fuzzy inference system (ANFIS). It is one of the artificial intelligence applications to improve grid-connected SOFC dynamic response. ANFIS is mathematically presented and simulated using MATLAB/SIMULINK. The results show that the ANFIS controller has succeeded in enhancing most of the desired control and operation signals. [ABSTRACT FROM AUTHOR]

This paper presents a study of the characteristic effects of the physicochemical properties of microcrystalline cellulose and a series of biocarbon samples produced from this raw material through thermal conversion at temperatures ranging from 200 °C to 850 °C. Structural studies revealed that the biocarbon samples produced from cellulose had a relatively low degree of graphitization of the carbon and an isometric shape of the carbon particles. Based on thermal investigations using the differential thermal analysis/differential scanning calorimeter method, obtaining fully formed biocarbon samples from cellulose feedstock was possible at about 400 °C. The highest direct carbon solid oxide fuel cell (DC-SOFC) performance was found for biochar samples obtained via thermal treatment at 400–600 °C. The pyrolytic gases from cellulose decomposition had a considerable impact on the achieved current density and power density of the DC-SOFCs supplied by pure cellulose samples or biochars derived from cellulose feedstock at a lower temperature range of 200–400 °C. For the DC-SOFCs supplied by biochars synthesised at higher temperatures of 600–850 °C, the "shuttle delivery mechanism" had a substantial effect. The impact of the carbon oxide concentration in the anode or carbon bed was important for the performance of the DC-SOFCs. Carbon oxide oxidised at the anode to form carbon dioxide, which interacted with the carbon bed to form more carbon oxide. The application of biochar obtained from cellulose alone without an additional catalyst led to moderate electrochemical power output from the DC-SOFCs. The results show that catalysts for the reverse Boudouard reactions occurring in a biocarbon bed are critical to ensuring high performance and stable operation under electrical load, which is crucial for DC-SOFC development. [ABSTRACT FROM AUTHOR]

The outstanding thermal, chemical, and mechanical properties of ceramic membranes have attracted increasing attention, offering advantages over polymer and metal counterparts. Exploring the specialized applications of ceramic membranes through various preparation methods poses a daunting challenge for contemporary researchers. Traditional preparation methods are essentially unable to meet the requirements of complex membrane structures. For instance, in ceramic fuel cell applications, cells composed of ceramic membrane materials exhibit high resistance and low conductivity, which seriously hinders the progress of new high-performance ceramic fuel cells. Therefore, it is necessary to improve preparation methods to improve the electrochemical performance of devices composed of ceramic membrane materials. In recent years, breakthroughs in various new processing technologies have propelled the performance of ceramic membrane devices. This paper will focus on the following aspects. Firstly, traditional preparation methods and advanced preparation methods of ceramic membrane materials will be discussed. Secondly, high-performance ceramic membrane materials prepared by different advanced preparation methods are introduced, and the electrochemical properties of the devices composed of ceramic membrane materials are elaborated in combination with different testing and characterization methods. Finally, the prospects and future direction of the preparation of ceramic membrane materials by advanced preparation methods are summarized. [ABSTRACT FROM AUTHOR]

The increasing global dependence on fossil fuels for energy has prompted researchers to explore alternative power generation sources that offer higher efficiency, cost-effectiveness, and low environmental impact. Developed countries have been making continuous efforts to reduce their reliance on depleting fossil fuel sources to curb carbon emissions. As a result, hydrogen has gained significant attention among researchers as a potential future fuel that meets all the necessary criteria. Many countries aiming for a hydrogen economy have invested in research on fuel cells. Among various fuel cells, the solid oxide fuel cell (SOFC) has emerged as a commercially viable power source at a small scale. This paper provides an extensive review of the components, materials, design, operation, and integration strategies of SOFCs with existing thermal-based power plants. The performance and prospects of various SOFCs in standalone and hybrid modes are summarized, along with the limitations. Additionally, the research and commercialization efforts that can enhance the potential applications of SOFCs as a sustainable and reliable system in the long term are outlined. [ABSTRACT FROM AUTHOR]

This review discusses the groundbreaking advancements in electric current-assisted sintering techniques, specifically Flash Sintering (FS) and Ultrafast High-Temperature Sintering (UHS), for their application in Solid Oxide Fuel Cells (SOFCs). These innovative sintering methods have demonstrated remarkable potential in enhancing the efficiency and quality of SOFC manufacturing by significantly lowering sintering temperatures and durations, thereby mitigating energy consumption and cost. By providing a detailed overview of the mechanisms, process parameters, and material characteristics associated with FS and UHS, this paper sheds light on their pivotal role in the fabrication of SOFC components such as electrolytes, electrodes, multilayered materials, and interconnect coatings. The advantages, challenges, and prospective opportunities of these sintering technologies in propelling SOFC advancements are thoroughly assessed, underlining their transformative impact on the future of clean and efficient energy production technologies. [ABSTRACT FROM AUTHOR]

The current state of mixed ionic–electronic conducting ceramic membrane technology presents significant advancements with potential applications in various fields including solid oxide electrolyzers, fuel cells, hydrogen production, CO2 reduction, and membrane reactors for chemical production and oxygen separation. Particularly in oxygen separation applications, optimal conditions closely align with the conditions of oxygen-rich air streams emitted from the anode of solid oxide co-electrolyzers. This paper describes and analyzes a novel integrated heat recovery system based on mixed ionic–electronic conducting membranes. The system operates in two stages: firstly, oxygen is separated from the anode output stream using mixed ionic–electronic conducting membranes aided by a vacuum system, followed by the heat recovery process. Upon oxygen separation, the swept gas stream is recirculated at temperatures near thermoneutral conditions, resulting in performance improvements at both cell and system levels. Additionally, an oxygen stream is generated for various applications. An Aspen HYSYS® model has been developed to calculate heat and material balances, demonstrating the efficiency enhancements of the proposed system configuration. [ABSTRACT FROM AUTHOR]

Locomotive engines serve as the powering heart of rail transportation which is widely used for massive cargo over long distances. The traditional locomotive engines have depended on the internal combustion engine for decades, operated using fossil fuels that negatively impact the environment. Since more and more commodities are transported by trains, the prime engines need to be improved where the fuels are expected to enhance the engine's performance and alleviate the environmental impact. This paper presents a comparison of three developed locomotive engines with different configurations, such as an internal combustion engine combined with a gas turbine and molten carbonate fuel cell (ICE-GT-MCFC), a gas turbine combined with a solid oxide fuel cell and onboard hydrogen production using aluminum electrolysis cell (GT-SOFC), and a GT combined with sold oxide and proton exchange membrane fuel cells (GT–SOFC–PEMFC). The paper then identifies one hybridized engine, which is GT–SOFC–PEMFC, according to its low weight and better performance to conduct an optimization study to enhance its efficiency, reduce the cost, and lower the environmental impact. The present optimization study is undertaken through a multi-objective particle swarm optimization, involving thermodynamic, exergoeconomic, and exergoenvironmental analyses. The optimized GT–SOFC–PEMFC locomotive engine is improved in power from 5.9 MW to 7.3 MW and improved in performance to 49.1% energetic efficiency and 47.0% exergetic efficiency. Additionally, the optimized GT–SOFC–PEMFC engine has less specific fuel and product cost of 24.9 $/GJ and 34.7 $/GJ, respectively, and less specific exergetic environmental impact of fuel and product of 13.2 Pt/GJ and 16.2 Pt/GJ, respectively. Also, the relative cost difference and relative environmental impact difference are significantly reduced by more than 20% to 39.4% and 22.8%, respectively. The operational conditions of the optimized GT–SOFC–PEMFC engine are improved to achieve better efficiency and better cost effectiveness in a more environmentally-benign manner. • Comparison between three hybridized combined locomotive engines is established. • Optimized GT–SOFC–PEMFC engine has 7.3 MW power and 49% energetic efficiency. • Specific exergetic product cost declined to 51 $/GJ for fuel and 35 $/GJ. • Specific exergetic environmental impact for fuel and product becomes 13 and 16 Pt/GJ. • The relative environmental impact difference becomes 22.8% instead of 44.3%. [ABSTRACT FROM AUTHOR]

Reversible solid oxide fuel cell (RSOC) has gained widespread attention due to their potential for high efficiency in implementing multi‐energy distributed systems. When high power demand is required, RSOC can operate in the solid oxide fuel cell (SOFC) mode, directly converting the chemical energy from hydrogen or other renewable fuels into electricity. When excess electricity is available, RSOC can operate in the solid oxide electrolysis cell (SOEC) mode, producing fuels through the electrolysis of water or co‐electrolysis of water and carbon dioxide. The reversible operation of RSOC enables the direct conversion between chemical energy and electricity, offering a promising solution for clean and sustainable energy with low cost and high round‐trip efficiency. This paper introduces the research background and working principles of RSOC, provides a detailed overview of the current research status of electrolyte, fuel electrode, and oxygen electrode materials, discusses the optimization design of RSOC stacks and energy utilization strategies in the system. In addition, the future development directions of RSOC were also explored, which is of significant importance for the commercialization of RSOC. [ABSTRACT FROM AUTHOR]

This paper introduces a novel five-port, three-input, dual-output isolated bidirectional dc-dc converter (FPIBC) topology with an effective controller for power-sharing and voltage-balancing in bipolar dc microgrids (BPDCMGs). The proposed converter acts as the interface for the integration of a hybrid generation system comprising a solid oxide fuel cell (SOFC), a photovoltaic (PV) system, and a battery into BPDCMGs. It employs a reduced number of circuit elements compared with similar multiport converter topologies suggested for BPDCMG applications. Symmetrical bipolar output voltages are ensured by a voltage-balancing circuit composed of a fully controlled switch and four diodes. The FPIBC is equipped with different controllers for output voltage regulation and balancing, power sharing, maximum power point tracking of the PV, the optimum operating region of the SOFC, and constant-current, constant-voltage charging of the battery. To verify the viability and effectiveness of the proposed system, a simulation model was developed with a 4.2 kW SOFC, a 3.7 kW PV, and a 140 V 10.8 Ah battery in MATLAB/Simulink. The performance of the FPIBC was evaluated through extensive case studies with different operational modes, including battery charge/discharge states and SOFC and PV parameter changes under varying load conditions. In addition, the proposed system was examined using a daily dynamic load profile. According to the simulation results, a peak efficiency of 97.28% is achieved and the voltage imbalance between the output ports is maintained below 0.5%. It is shown that the FPIBC has advantages over previous converters in terms of the number of ports, number of circuit elements, bipolar output voltage, bidirectional power flow, and efficiency. [ABSTRACT FROM AUTHOR]

This paper examines the current and prospective greenhouse gas (GHG) emissions of e-fuels produced via electrolysis and Fischer–Tropsch synthesis (FTS) for the years 2021, 2030, and 2050 for use in Germany. The GHG emissions are determined by a scenario approach as a combination of a literature-based top-down and bottom-up approach. Considered process steps are the provision of feedstocks, electrolysis (via solid oxide co-electrolysis; SOEC), synthesis (via Fischer–Tropsch synthesis; FTS), e-crude refining, eventual transport to, and use in Germany. The results indicate that the current GHG emissions for e-fuel production in the exemplary export countries Saudi Arabia and Chile are above those of conventional fuels. Scenarios for the production in Germany lead to current GHG emissions of 2.78–3.47 kgCO2-eq/L e-fuel in 2021 as the reference year and 0.064–0.082 kgCO2-eq/L e-fuel in 2050. With a share of 58–96%, according to the respective scenario, the electrolysis is the main determinant of the GHG emissions in the production process. The use of additional renewable energy during the production process in combination with direct air capture (DAC) are the main leverages to reduce GHG emissions. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of the reduction in the huge energy demand of hospitals and health care facilities. The sharp increase in the natural gas price, due to the Ukrainian–Russian war, has significantly reduced economic savings achieved by combined heat and power (CHP) units, especially for hospitals. In this framework, this research proposes a novel system based on the integration of a reversible CHP solid oxide fuel cell (SOFC) and a photovoltaic field (PV). The PV power is mainly used for balancing the hospital load. The excess power production is exploited to produce renewable hydrogen. The SOFC operates in electrical tracking mode. The cogenerative heat produced by the SOFC is exploited to partially meet the thermal load of the hospital. The SOFC is driven by the renewable hydrogen produced by the plant. When this hydrogen is not available, the SOFC is driven by natural gas. In fact, the SOFC is coupled with an external reformer. The simulation model of the whole plant, including the reversible SOFC, PV, and hospital, is developed in the TRNSYS18 environment and MATLAB. The model of the hospital is calibrated by means of measured data. The proposed system achieves very interesting results, with a primary energy-saving index of 33% and a payback period of 6.7 years. Therefore, this energy measure results in a promising solution for reducing the environmental impact of hospital and health care facilities. [ABSTRACT FROM AUTHOR]

Previous studies have found that in ceramic fuel cells using Ni 0·8 Co 0·15 Al 0·05 LiO 2 (NCAL) as the electrode, lithium compounds such as LiOH generated by reduction of NCAL anode by H 2 diffuse into oxide electrolyte membranes such as Gd 0.1 Ce 0·9 O 2 (GDC), and the "GDC-lithium compounds" composite electrolyte formed online is an excellent proton conductor. In this paper, the low-temperature electrolysis performance of proton conductor type solid oxide electrolysis cell (P-SOEC) with GDC as electrolyte and NCAL as electrode for direct electrochemical conversion of H 2 O into H 2 was investigated. It is found that at operation temperature of 550 °C, the current density of the SOEC prepared in this paper can reach 2.263 A cm−2 at 1.6 V. The composite electrolyte in the electrolysis cell reaches an ionic conductivity of 0.572 S cm−1 in the SOEC mode. The excellent hydrogen production performance proves that this new type of electrolysis cell with lithium compounds as electrodes is a promising and potential proton conductive low-temperature SOEC. • SOEC with NCAL electrodes was fabricated. • Proton conductivity of the composite electrolyte reaches 0.572 S cm−1 at 550 °C. • The electrolytic current density of the SOEC reaches 2.263 A·cm−2 at 1.6 V. • Provided a new type of SOEC and related electrolytic cell material. [ABSTRACT FROM AUTHOR]

An alkaline electrolyzer is a traditional equipment to generate hydrogen. Improving the yield of electrolyzers has recently captured much attention. In this regard, the utilization of carbon-coated nanomaterial structures is a state-of-art method. On the other hand, considering the current crisis of fossil energies, the exploitation of renewables and green technologies is necessary and unavoidable. Additionally, the design and development of integrated energy systems with two or more output products and the maximum usage of thermal losses to enhance productivity can increase the flexibility and acceptability of the energy system. In this regard, the current paper develops a framework for the performance of a new solar and biomass energies-driven multigeneration system (MGS). The main units installed in MGS are three electric energy generation units based on a gas turbine process, a solid oxide fuel cell unit (SOFCU) and an organic Rankine cycle unit (ORCU), a biomass energy conversion unit to useful thermal energy, a seawater conversion unit into useable freshwater, a unit for converting water and electricity into hydrogen energy and oxygen gas via a nanomaterial-based alkaline electrolyzer, a unit for converting solar energy into useful thermal energy (based on Fresnel collector), and a cooling load generation unit. The planned MGS has a novel structure and layout that has not been considered by researchers in previous papers. The current article is based on presenting a multi-aspect evaluation in order to investigate thermodynamic-conceptual, environmental and exergoeconomic analyzes. The outcomes indicated that the planned MGS can produce about 6.31 MW of electrical power and 0.49 MW of thermal power. Furthermore, MGS is able to produce various products such as potable water (∼0.977 kg/s), cooling load (∼0.16 MW), hydrogen energy (∼1.578 g/s) and sanitary water (∼0.957 kg/s). The overall energy and exergy productivities were measured as 78.13% and 47.72%, respectively. Also, the total investment and unit exergy costs were 47.16 USD per hour and 11.07 USD per GJ, respectively. Further, the content of carbon dioxide released from the planned system was equal to 10.59 kmol per MWh. A parametric study has been also developed to identify influencing parameters. • The nanomaterial-based alkaline electrolyzer is utilized for hydrogen production. • The system is tested by thermodynamic and environmental aspects. • The developed system was capable of generating 1.578 g/s hydrogen energy. • The content of carbon dioxide released from the planned system was less than traditional systems. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cell (SOFC) is regarded as a promising energy conversion device because of its advantages such as high efficiency and fuel flexibility. With the advent of aviation electrification era, SOFC has been gradually studied as aviation power system. However, the high temperature operation and temperature gradient of SOFC bring challenges to practical application. Nowadays SOFC systems often use excessive air as coolant to reduce the temperature gradient of SOFC, which leads to the increases of the fuel consumption and reduction of the power generation efficiency. In order to maintain a lower temperature gradient with less air, a supercritical fuel cooled SOFC scheme is proposed in this paper. By establishing a one-dimensional model of conventional air-cooled fuel cell and fuel cell with fuel cooling channel. Through calculating the fuel cell temperature gradient under different working conditions, the results show that when the excess air coefficient (EAC) is 3, the temperature gradient of air-cooled SOFC reaches 22.7K/cm, while the temperature gradient of SOFC with fuel channel decreases to 8.35K/cm. Therefore, the SOFC with fuel channel can effectively reduce the use of air, reduce parasitic power consumption and improve the efficiency of the system while maintaining a lower temperature gradient. • A supercritical fuel cooled SOFC scheme is proposed in this paper. • When the excess air coefficient is 3, the temperature gradient of fuel cell with fuel channel decreases to 8.35K/cm. • The fuel cell system with fuel channel can effectively reduce the use of air. • The SOFC scheme of fuel cooling can improve the electrochemical performance of SOFC. [ABSTRACT FROM AUTHOR]

Energy generation systems based on FC (fuel cell) are viewed as a viable substitute for those that simply rely on thermodynamic cycles in the power production field. In this paper, a 10-stack SOFC systems performance and optimization of that utilizing a newly improved optimizer known as the Fractional-order Kho-Kho optimization method will be presented in this paper. The multi-objective optimization approach is applied in the optimization phase to achieve the desired performance goals for the SOFC system. With the help of this technique, the desired system can be optimized in accordance with two objective functions: first, the electric power of the system can be maximized, while the equalized price of the electricity produced is minimized. Then, the electrical efficiency of the system can be maximized, while the equalized price of the electricity produced is minimized. The results show that, by reducing the coefficient and increasing efficiency, optimal solutions were achieved with higher electricity prices. It is observed that an increase in energy prices led to a 9% increase in productivity, whereas a 15% increase resulted in only a 2% increase. The findings demonstrate that multi-objective optimization may be used as a sophisticated analytical tool as well as a guiding element for decision-makers utilizing such a system. [ABSTRACT FROM AUTHOR]

This paper investigates the creep behavior, damage evolution, and failure probability of a solid oxide fuel cell (SOFC) with three different flow channel geometries—rectangular, round trapezoidal, and arched—under non-uniform temperature conditions over a 60,000 h operational period. A strain-based creep damage and failure probability model was developed to analyze the stress-strain distribution, creep damage evolution, and failure probability development inside the SOFC components. Results indicate a significant influence of SOFC channel geometry on stress relaxation. The three channel SOFC, rectangular, round trapezoidal, and arched, reach the damage threshold after 57,062 h, 43,577 h, and 49,560 h of operation, respectively, with crack initiation occurring near the inlet and outlet of the upper interconnector. The anode material exhibited the highest probability of failure, increasing by 116.3% and 36.4% for the transition from rectangular to round trapezoidal and arch-shaped gas channels, respectively. This study underscores the advantages of SOFC with rectangular channels in terms of mechanical stability and longevity, providing crucial insights for optimizing SOFC design and enhancing commercial viability. • Derivation of the non uniform temperature fields of different channel SOFCs. • Comparison of vulnerable locations in different channel SOFC components. • Evolution of creep damage in different channel SOFCs during 60 000 h of operation. • Study on the failure probability of different channel SOFCs. [ABSTRACT FROM AUTHOR]

Intake parameters are essential factors that are often overlooked, but can easily change the direct internal reforming solid oxide fuel cell (DIR-SOFC) performance. A three-dimensional model is developed to simulate the effects of intake parameters on the performance of an anode-supported flat-plate DIR-SOFC. The two primary chemical reactions, water gas shift reaction (WGSR) and methane steam reforming reaction (MSR), as well as the electrochemical oxidation of H 2 and CO, are considered in this model. It was found that the aspect ratio corresponding to the peak current density decreases as fuel increases. A moderate air flow rate makes the fuel-to-air ratio (FAR) corresponding to the drastic change in current density relatively small and wide-ranging, resulting in more desirable temperature distribution and fuel utilization. Under the operating conditions of this paper, adjusting the steam-to-carbon ratio (S/C) to between 1.5 and 2 results in both excellent electrical performance and good temperature uniformity. Additionally, adjusting the flow rate by changing the inlet area or velocity has its own advantages in terms of temperature distribution or current density, which must be taken into account when adjusting the flow rate. This study provides a valuable reference on inlet settings of DIR-SOFC, which would help to promote the development of high-performance SOFCs. • A three-dimensional flat-plate DIR-SOFC model has been developed. • Oxidation reaction of CO is included in the mode. • Different flow rates would change the effects of the aspect ratio and S/C. • Impacts of the fuel-air ratio are analyzed fully in terms of both fuel and air sides. • Changing the flow rate by altering the area or speed can make differences. [ABSTRACT FROM AUTHOR]

A solid oxide fuel cell (SOFC) is a clean and very efficient electrochemical conversion device, which generates electricity directly from fuel electrochemical oxidation. In this paper, a three dimensional numerical model has been developed in order to analyse the role of some thermophysical and morphological parameters on the performance of the SOFC cell. In particular, we studied the effect of the variation of permeability of the electrodes: fuel distribution, ionic and electric current density, pressure and diffusion flux are analyzed and compared. The volume fraction of the ionic and electronic phase in the electrodes is studied using a parametric study. It was shown that the current density enhanced by decreasing the permeability, up to a defined value, and it diminished with very small permeability. A remarkable influence of pressure and diffusion of species on the performance of the cell, with the variation of permeability, has been recognized. Varying the permeability in the active layer of electrodes has a large impact on the current density, connected to the volume fraction of ionic phase. This study permits to comprehend the relationship between the performance and microstructure of SOFCs. Meanwhile, it furnishes theoretical guidance for an optimum design of the electrode permeability. • A three-dimensional model of a single SOFC is developed using CFD method. • Varying the permeability of electrode components affects the cell performance. • The impact of volume fractions for different permeabilities is studied. • It is concluded that there is an optimum design of the electrode permeability. [ABSTRACT FROM AUTHOR]

Efficient and reliable utilization of renewable energy at the user's end is the key to achieving a low‐carbon life. This paper proposed a new distributed energy system around the comprehensive utilization of solar energy by integrating solid oxide fuel cell (SOFC), energy storage equipment, photovoltaic thermal (PVT) collector, and heat pump. By integrating the use of SOFC and PVT, we can further minimize reliance on fossil fuels, while employing the coupling of PVT and heat pump effectively mitigates the inherent challenges of solar energy's variability and intermittency, all while enhancing overall system efficiency. On this basis, we apply the heat current method to construct a cross‐scale heat current model of the components and the system by considering the energy transfer, conversion, and storage characteristics of the system. By employing this model, we simulate the system's operation throughout an entire typical day, assess the COP enhancement of the PVT‐coupled heat pump system, analyze the influence of diverse operating conditions on daily system performance, and evaluate the economy of the energy storage devices in the system. [ABSTRACT FROM AUTHOR]

The article discusses the importance of advanced characterization techniques in achieving net zero emissions, particularly in the chemical industry. Topics discussed include the role of catalysis in reducing emissions, the development of next-generation analytical tools, and the integration of machine learning and laser-based spectroscopies in material science.

Multiphysics simulations of solid oxide cell (SOC) require extensive experience and can be labor intensive. This paper reports the first successful implementation of automated multiphysics simulation process for industrial-scale planar SOC stacks. The automation is realized through Python based Ansys SpaceClaim scripting for building geometric model, Python based Ansys Workbench Meshing scripting for setting numerical grids, and Scheme based Ansys Fluent TUI commands for performing multiphysics simulations. The model building process allows for customized dimensions of all stack components and the corresponding edge grid counts. The automation of simulations streamlines all the computational steps in multiphysics modeling. The multiphysics model is shown to agree well with the experimental data. The automated tool is illustrated in a parametric analysis of SOC operations, illuminating the influences of size, shape and thermal boundary on the stack performance. The automation makes the simulations simple and efficient, invaluable for the SOC design and operation analysis. • First realization of automated multiphysics modeling of production-scale SOC stacks. • Techniques for automated high-fidelity geometry model building and mesh creation. • Simulation of 6 different sized kW-scale stacks & with different thermal conditions. • Mechanism for the influences of stack size and shape on physical fields revealed. [ABSTRACT FROM AUTHOR]

With the increasing consumption of fossil fuels, there is an urgent need to develop a new green and clean energy source. Fuel cells have been extensively studied as a clean alternative to fossil fuels. As a green energy source, direct methanol fuel cells (DMFCs) have high energy density; however, their commercialization is restricted by the poor stability and slow kinetics of methanol oxidation reactions (MORs). One of the key strategies to overcome these problems is to develop efficient, economic and green catalysts for energy storage and conversion devices. Thus far, Pt-based electrocatalysts have been extensively used to enhance the oxidation process of CH3OH. However, since Pt-based electrocatalysts are limited by high cost and susceptibility to CO poisoning, researchers have been motivated to search for a cost-effective, highly active and durable catalytic material. In recent years, Co-based spinel oxides have been found to exhibit good potential as fuel cell electrode materials, they can be modified by defect engineering, alloying and heteroatom doping, or more active sites can be exposed by morphology regulation or carrier regulation, so as to improve their electrocatalytic performance. This review provides a comprehensive introduction to the recent development of Co-based spinel electrocatalysts for emerging MORs involved in DMFCs, and the future development of low-cost and high-performance Co-based spinel oxide catalytic materials is prospected. [ABSTRACT FROM AUTHOR]

Waste heat is one of the major problems associated with the energy system. This paper discusses an energy, exergy, and emissions approach for the hybrid system by utilizing waste heat to the maximum extent. A thermoelectric generator (TEG) is incorporated to utilize the low-temperature waste heat from a hybrid model of a solid oxide fuel cell (SOFC) and a combined heat and power (CHP) system. SOFC is an electrochemical cell that generates power at high temperatures through an electrochemical reaction. The high-temperature, unutilized fuel leaves the SOFC, which is burned in the afterburner. The afterburner temperature controls the operating temperature of SOFC. Here, three recuperators are used to utilize this high-temperature waste heat to improve the performance of SOFC and simultaneously generate heat power from the water or gas recuperator. TEG is an auxiliary power production technology that converts waste heat into energy. A novel integration of TEG with SOFC–CHP hybrid system to utilize the low temperature waste heat, is employed. The main goal of this study is to analyze a novel SOFC–CHP-TEG hybrid system in terms of its thermodynamics and emissions. A Two stage TEG is integrated with the SOFC–CHP hybrid system. The simulation model of high temperature fuel cell (SOFC) is developed on MATLAB and validated with published results. This study analyses the impact of pressure ratio and afterburner temperature on the performance of SOFC–CHP-TEG. To do this, perform energy and exergy assessments using the principles of the first and second laws of thermodynamics. A novel exergy-based sustainability index with emissions analysis for the proposed SOFC–CHP is presented. The achieved overall energy efficiency is 62.54% at a pressure ratio of 12 and an afterburner temperature of 1000 K. With an increase in pressure ratio and temperature, the level of CO emissions reduces significantly. [Display omitted] • A novel energy exergy for SOFC–CHP-TEG system is presented. • Exergy based performance is compared and achieve 56.62. • Utilization of waste heat via TEG. • Energy efficiency of SOFC–CHP-TEG is 62.54% at rp = 12 and afterburner temperature of 900 K. [ABSTRACT FROM AUTHOR]

The flow field design is very essential to the material distribution uniformity and overall output performance of planar solid oxide fuel cells. In this paper, the structure of the external manifold and cathode side interconnect is optimized to solve the uneven flow field distribution problem. The effects of crucial geometric parameters on the internal mass transfer, component transport, electrochemical reaction, temperature field and overall output performance of the fuel cell are studied by three-dimensional multi-physics numerical simulation. It is found that the combination of the three-inlet-two-outlet external manifold and cylindrical ribbed interconnect significantly reduces the uneven gas distribution between different channels and greatly improves the diffusion of oxygen under the ribs, thus enhancing the overall output performance of SOFC. Increasing the number of cylindrical ribs is beneficial to the transport and uniform distribution of oxygen. However, the excessive number of cylindrical ribs will hinder oxygen diffusion to the end of the flow channel, resulting in increased concentration polarization along the flow channel. Moreover, reducing the total contact area of the ribs enhances oxygen diffusion beneath the ribs but also raises the contact resistance and may deteriorate the cell performance. • The structure of external manifold and cathode side interconnect is optimized. • The discrete cylindrical ribs significantly enhance the diffusion of oxygen beneath the ribs. • An excessive quantity of cylindrical ribs hinder the flow of oxygen to the end of the channel. • Reducing the contact area of the ribs leads to a rise in ASR and performance degradation. [ABSTRACT FROM AUTHOR]

This study examines the feasibility of using hydrogen as a clean energy source for residential consumers in the UK through a low-carbon energy hub. Two cases were compared: a solid oxide fuel cell (SOFC) integrated combined heat and power (CHP) system fuelled by natural gas and hydrogen; and a SOFC-heat pump (HP) integrated CHP system fuelled by natural gas and hydrogen. The study used the actual electricity and heating demands of a UK cluster to model the CHP systems. The results indicate that the SOFC-based CHP system with hydrogen as fuel is more energy-efficient than the natural gas-fuelled system, with energetic efficiencies of 92.12% and 66.98%, respectively. The study also found that the system incorporating a heat pump is more economically viable, regardless of the fuel source, with the hydrogen-powered system equipped with a heat pump having a levelised cost of energy (LCOE) of 0.2984 £ per kW h. The study also evaluated the environmental impact of the natural gas-powered SOFC and SOFC-HP systems, with estimated levelised CO2 emissions of 0.308 kg per kW h and 0.213 kg per kW h, respectively. The study's findings provide insights into the potential of hydrogen as a cleaner energy source for residential consumers in the UK and highlight the importance of exploring low-carbon energy alternatives. [ABSTRACT FROM AUTHOR]

For metal-supported solid oxide fuel cells, gadolinium-doped cerium ceria (GDC) is one of the most promising electrolyte materials due to its high ionic conductivity at medium and low temperatures. However, using traditional sintering method to prepare GDC electrolytes at high temperature can lead to interdiffusion between the metal supports, electrolytes, and electrodes, which can seriously impact cell performance. In this paper, the GDC electrolytes were prepared using atmospheric plasma spraying technology, which could avoid the issue of high-temperature sintering. The effects of different spraying distances on the microstructure, interface, and cell performance were studied. The results show that the cell performance is optimal when the spraying distance is 80 mm. The open-circuit voltages of the single cell at 500, 600, and 700 °C are 0.866 V, 0.82 V, and 0.75 V, respectively. The peak power densities at these temperatures are 66.2, 182.8, and 386 mW/cm2, respectively. It provides a reference value for the commercialization of metal-supported solid oxide fuel cells prepared by plasma spraying. [ABSTRACT FROM AUTHOR]

Reversible solid oxide cells (RSOCs) hold enormous potential for efficient direct CO2 reduction or CO oxidation in terms of exceptional faradic efficiency and high reaction kinetics. The identification of an active fuel electrode is highly desirable for enhancing the performance of RSOCs. This study explores the use of a alkaline metal dopant (Na) to modify the perovskite oxide of Na2x(La0.6−xSr0.4−x)FeO3−δ (2x = 0, 0.10, 0.20) materials with powerful CO2 chemical adsorption capacity, high oxygen ion conductivity, and low average valence of Fe sites for CO2/CO redox reactions. The experimental results indicate that the cells with the NaLSF0.10 fuel electrode achieve a current density of 1.707 A cm−2 at 1.5 V/800 °C and excellent stability over 120 hours at 750 °C for pure CO2 electrolysis, approximately 33.4% improvement over the pristine sample. When operated under a mixed CO–CO2 atmosphere under RSOC mode, the cell outputs the performance of 1.589 A cm−2 at 1.5 V and 329 mW cm−2 at 800 °C, and demonstrates relatively durable operation over 25 cycles. The addition of low valence sodium ions with high basicity and low electronegativity reduces the oxygen vacancy formation energy, increases the concentration of oxygen vacancies and modifies the electronic structure of LSF, thus enhancing CO2 adsorption, dissociation processes and charge transfer steps as corroborated by the detailed experimental analysis. Combined with the acceptable anti-carbon deposition capability, we prove here a feasible strategy and provide new insights into designing novel electrodes for SOEC/RSOCs to effectively convert CO2 with potential for renewable energy storage. [ABSTRACT FROM AUTHOR]

Developing novel solid oxide fuel cells (SOFCs) with high stability running at low temperatures is an important objective in SOFC science. In the current paper, a comprehensive physics-based microstructure modeling using scanning electron microscope (SEM) image analysis was performed on several anode-support SOFCs operating at low temperatures with high stability. To bridge the gap in the literature regarding an accurate and realistic modeling, a new model was developed based on the variable fuel and air utilization factors and updated microstructure values (e.g., tortuosity, porosity, pore size, grain size). The model accuracy was verified by a thorough point-to-point validation for eight different cells with the configuration of Ni-YSZ (anode), YSZ (electrolyte), and GDC/PNO (cathode). Different temperatures, hydrogen, and air mass flow rates were used, for which an average error of less than 3% in the I-V curves was achieved. The microstructure of the cells, including cathode thickness (15–26 μm), anode-support thickness (350–460 μm), porosity (39 and 43%), grain size (1.1–1.4 μm), and pore radius (0.9–1.1 μm) were varied. Moreover, the effects of the critical operational and design parameters on the overpotential losses and cell performance were studied. The results show that a hydrogen flow rate of 43 sccm was ideal when the cell operated at 0.9 A/cm2 and 700 °C. Moreover, an average anode-support pore radius of 1.75 μm resulted in the best cell performance. It was also concluded that the electrolyte thickness has a higher effect on the cell performance compared to the cathode thickness. • Fabrication and testing of eight anode-supported tublar cells with different microstructures. • Introducing a physics-based microstructure model for SOFC based on variable fuel utilization factor. • Performing a comprehensive SEM image analysis for the fabricated cells. • Achieving an average error of less than 3% for the model compared to the experimental data. • Achieving an average optimum value of 1.75 μm for anode-support pore radius. [ABSTRACT FROM AUTHOR]

This article considers and studies a hybrid energy storage system as a potential replacement for a utility grid. It also examines its organisational structure. The hybrid energy storage technology is used to ensure a constant supply of convenient grid electricity that is sufficient to handle changing power spikes. Batteries are used to stabilise the surges with measurable variation, whereas a massive capacitor is utilised to stabilise the surges with fast variation. In isolated areas where connecting to the main utility grid is impractical, standalone renewable generation may provide the advantage of a reduced operational cost as well as a reduction in protection fees. In order to encourage non-conventional power production in the overall renewable energy system, advancements in solid oxide fuel-cell technology and solar photovoltaic (PV) technology have also been made. Grid-coupled solar PV energy producing systems are being extensively used worldwide, and solar PV modules are increasingly being used in residential applications linked to the electrical grid. [ABSTRACT FROM AUTHOR]

The energy sector is actively transitioning towards climate-neutral solutions, emphasizing advancements in clean power generation technologies. Cogeneration systems based on solid oxide fuel cells (SOFC) currently exhibit higher electrical efficiencies than conventional plants, but their operation can still be improved. One of the approaches to increase its efficiency is implementing anodic off-gas recirculation. In this work, a numerical model of a 10 kW SOFC installation with anodic gas recirculation was analyzed using Aspen HYSYS software. System fueled with three alternative fuels (natural gas, hydrogen, and ammonia) was tested. In this paper it was proven that anode-off gas recirculation improves the electrical and total efficiency of the system for each fuel type. The cogeneration unit with a SOFC stack can operate safely over a wide range of recirculation ratios without need for additional modifications. Ammonia-fueled units achieve electrical efficiency (55%) higher than hydrogen-based system (47.6%) but lower than installation fueled with natural gas (61.8%). • Anode off-gas recirculation in combined heat and power based on SOFC was studied. • Three fuels where considered: nautral gas, hydrogen and ammonia. • Wide range of recirculation can be achieved for all three fuels without modification. • Optimal recirculation ratio was found for each fuel and stack fuel utilization factor. • Highest electrical efficiency of up to 61.8% is achieved for natural gas fueled system. [ABSTRACT FROM AUTHOR]

In present paper, a strain-based creep damage and failure probability model is constructed to conduct time dependent mechanical performance analysis of solid oxide fuel cell (SOFC) with nonuniform temperature fields obtained by multiphysics coupled modeling at an operational temperature of 800 °C. It demonstrates that assuming uniform temperature fields significantly underestimates the creep damage and failure probability of SOFC components compared to nonuniform temperature fields. The upper interconnector reaches the critical damage value at 54 117 h and initiates a crack, located on the outer surface of the upper interconnector rib, positioned 39 mm from the fuel outlet. After 55 000 h, the failure probability of the anode support is rapidly increasing, reaching 0.185 after 80 000 h, which is 5–6 orders higher than other components. The upper interconnector and anode support are potential failure components, which should be subject to safety inspection to ensure structural integrity after 55 000 h of operation. • The necessity of obtaining realistic temperature field under the multiphysics coupled clearly demonstrated. • Location of potentially dangerous SOFC components revealed. • Evolution of creep damage and failure probability of SOFC during 80 000 h operation. [ABSTRACT FROM AUTHOR]

The low ionic conductivity of proton conductor electrolytes at low temperatures was one of the key issues that restrict the reduction of operating temperature in ceramic fuel cells. The traditional Y-doped BaCeO 3 proton conductor (BCY) has an ionic conductivity of only a few tens of mS·cm−1 at 500 °C, which cannot meet the needs of high-performance low-temperature ceramic fuel cells. In this paper, we found that the ionic conductivity of the composite electrolyte made by adding 20 % Li 2 O to BCY at 550 °C was 0.526 S cm−1, which was 40 times that of the dense BCY electrolyte sintered at 1550 °C. The maximum power density of a ceramic fuel cell using a BCY- Li 2 O composite material with a thickness of 1 mm as the electrolyte and porous Ag as the symmetrical electrode was 129 mW cm−2 in H 2 at 550 °C. The characterization results of XRD, EPR, and FTIR showed that there may be a region with a large number of oxygen vacancies and lithium vacancies created at the interface of the BCY and Li 2 O–LiOH composite electrolyte formed in the BCY-Li 2 O composite electrolyte during the testing conditions for fuel cell performance due to the migration of Li+. The formation of this region should be the main reason for the extremely high conductivity of the BCY-Li 2 O–LiOH composite electrolytes formed in the cell at low temperatures. [ABSTRACT FROM AUTHOR]

The increasing demand for green hydrogen and power production necessitates the development of novel and upgraded power generation technologies. The solid oxide fuel cell combined heat and power (SOFC–CHP) system is a promising solution due to its high efficiency, clean operation, and fuel flexibility. In practical terms, SOFCs can operate using a variety of fuels such as alcoholic fuel, hydrogen, ammonia, etc. Recently, methanol and ammonia have become noteworthy alternative fuel options as it possesses advantages such as low transportation cost and high hydrogen storage capacity. In this paper, we have established two SOFC–CHP models fueled by methanol or ammonia integrated with the steam Rankine cycle. A comprehensive thermodynamic model is proposed for energy and exergy analyses. Sensitivity analysis is performed to study the system's characteristics. The results show that the SOFC–CHP system fueled by ammonia exhibits superior performance, the maximum electrical power, efficiency, and exergy efficiency is 430W, 7% and 10% greater than the methanol fueled system. The operating temperature is about 30K higher in methanol supplied system. The largest thermal power difference can reach 0.65 kW. Overall, the ammonia fueled SOFC–CHP system shows greater potential than that fueled by methanol. [Display omitted] • Using ammonia as fuel can improve energy and exergy efficiency by 7% and 10%. • Methanol fueled system requires almost half fuel than that supplied by ammonia. • The operating temperature is about 30K higher in methanol supplied system. • The largest thermal power difference can reach 0.65 kW. • The exergy destruction of preheat process accounts for the majority of both systems. [ABSTRACT FROM AUTHOR]

Ni-impregnated Gd 0.1 Ce 0.9 O 2 and Y 0.08 Zr 0.92 O 2 fuel electrodes for solid oxide cells are manufactured by the combination of the freeze tape casting and infiltration techniques. Their morphological properties are investigated by scanning electron microscope and X-Ray microtomography while their electrochemical performance is evaluated in symmetrical Y 0.08 Zr 0.92 O 2 -supported button cells by electrochemical impedance spectroscopy. The microstructural analysis of the manufactured scaffolds highlights the characteristic anisotropy of porosity provided by the freeze tape casting method. The average tortuosity factor across the out of plane direction has been calculated equal to 1.38, being considerably lower than the average values of the other components, (τ x = 10.2) and (τ y = 6.87). The contribution provided by gas diffusion to the overall polarization resistance of the freeze tape cast electrodes has been estimated around 6·10−4 Ω cm2 in the 600–750 °C temperature range, thus lower than the best reported values for the state-of-the-art electrodes featuring sponge-like porosity. The measured impedance data highlighted the higher electrochemical performance of the Ni-impregnated Gd 0.1 Ce 0.9 O 2 architecture, holding a polarization resistance of 0.823 Ω cm2 at 750 °C, which is regarded as a very promising result for a ∼600 μm thick electrode. The interpretation of the impedance data was supported by the distribution of relaxation times analysis and the complex non-linear least square fit. In particular, the electrochemical investigation highlighted the presence of two major resistive contributions which have been ascribed to the occurrence of a chemical capacitance within the GDC10 lattice (low frequency contribution) and to the multi-layered architecture of the tested symmetrical cells which increases the contact losses (high frequency contribution). • The electrode design optimization is expected to increase its electrochemical performance. • Nanostructured graded porous electrodes for SOCs are shaped combining freeze tape casting and infiltration. • The anisotropy of gas diffusion channels is highlighted by the 3D reconstruction of the GDC10 scaffold. • The Ni-infiltrated GDC10 freeze tape cast scaffold is measured to be the best performing electrode architecture. • The electrochemical performance of the Ni-GDC10 electrode is mainly hindered by its low electronic conductivity. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cell (SOFC) is a promising energy conversion technology for accelerating the process of carbon neutrality. This paper develops and validates a 1D mathematical model for a planar SOFC (10 cm × 10 cm) along the fluid flow direction with a less than 0.2% deviation. When the SOFC operates in an adiabatic environment with different inlet gas temperatures (T in) and current density (I avg), the distributions of its key parameters are calculated and analyzed. The results show that the optimal inlet gas temperature for the SOFC working in an adiabatic environment is between 873 K and 973 K when I avg varies from 0.05 A cm−2 to 0.25 A cm−2. The maximum temperature appears at the outlet position and between the outlet and the center point along the flue flow for the co-flow and counter-flow SOFC. Compared with the co-flow pattern, the counter-flow design can benefit the fuel cell power output when T in and I avg are identical, especially with lower T in and higher I avg. The output power of counter-flow SOFC is larger 11.3% than that of the co-flow one at most with the research range in this work. • A 1D model of the SOFC is developed and validated within 0.2% deviation. • Distribution characteristics of the SOFC in the adiabatic environment are analyzed. • The temperature gradient of the fuel cell decreases with the inlet gas temperature. • 11.3% more power can be obtained by adopting counter-flow SOFC in adiabatic. • The optimal inlet gas temperature varies from 873 K to 973 K for the adiabatic SOFC. [ABSTRACT FROM AUTHOR]

Although button solid oxide fuel cells (SOFCs) have been extensively used in fundamental research, practical commercial applications are developed on industrial-sized SOFCs. As the active area and fuel utilization increase, some issues that are not considered in button cells become essential. Therefore, it is necessary to focus on the differences between button cells and industrial-sized cells, including their polarization characteristics and performance evaluation. In this study, the polarization curves of both types of cells under different hydrogen flow rates are tested. Both types of cells experience a sudden increase in total area-specific resistance (R tot) under high current density. However, the effects of hydrogen flow rate differs between cell types. Based on the equivalent circuit model (ECM) fitting of electrochemical impedance spectroscopy (EIS) measured under different DC biases and the theoretical calculation of gas diffusion and gas conversion resistances, it is demonstrated that the rapid increase in R tot in button cells is primarily attributed to gas diffusion through the anode. In contrast, non-uniform gas distribution along the flow channel direction results in a dominant role of gas conversion resistance on R tot in industrial-sized cells, especially at hydrogen flow rates below 0.4 L min−1. Although electrical efficiency is often overlooked in button cells, it is a crucial performance evaluation index in industrial-sized cells. The impact of operating parameters on power density and electrical efficiency is analyzed, revealing a trade-off between the two. With the critical Nernst electromotive force of Ni oxidation as the voltage lower limit, the optimal operating conditions with high electrical efficiency and prevention of Ni oxidation under different flow rates are obtained. It is investigated that operation should be carried out at a low flow rate below 0.3 L min−1 to achieve high electrical efficiency of over 50%. The selected operating parameters will change when the cell performance or load demand changes. However, the analysis method proposed in this paper can still provide a reference for selecting the operating parameters of a SOFC system. • Comparison of polarization characteristics between button and industrial-sized SOFCs. • Dominant process of polarization in industrial-sized cells varies at different flow rates. • High voltage at high fuel utilization with low flow rate prevents Ni oxidation. [ABSTRACT FROM AUTHOR]