Performance Of Solid Oxide Fuel Cells Research Articles

Highly functional molten sodium hydroxide-BaZrO3 composite electrolyte with hybrid ionic conductivity for low-temperature solid oxide fuel cells

Proton-conducting barium zirconate perovskite attracts considerable attention as an electrolyte for solid oxide fuel cells (SOFCs). To obtain BaZrO3-based electrolytes with high ionic conductivity at low temperatures, composite electrolytes named BaZrO3+x wt% NaOH are designed and synthesized. A study is conducted to explore the effects of molten-state NaOH and a small amount of Na2CO3 generated during SOFC operation on the performance of composite electrolytes systematically. As a result of the addition of NaOH, the composite electrolyte is created with rich surfaces and solid-liquid interfaces, compared to traditional condensed electrolytes.The solid-liquid interface can serve as a high-speed ion conduction channel. In-situ surface oxygen deficiency induced by NaOH and the bridge function of carbonate enable rapid ion migration along the interface of the composite electrolyte. The fuel cell with the prepared electrolyte can deliver an excellent maximum power density (MPD) of 1039 mW cm-2 at 550 °C. At 350 °C, the cells are also able to show a very impressive power density of 365 mW cm-2. The concise design, convenient preparation process, and outstanding performance of the fuel cell collectively offer an effective strategy for advancing the manufacture of electrolyte materials for low-temperature operation.

A Review on Solid Oxide Fuel Cell Technology: An Efficient Energy Conversion System

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.

Thermal Stress in Full-Size Solid Oxide Fuel Cell Stacks by Multi-Physics Modeling

Mechanical failures in the operating stacks of solid oxide fuel cells (SOFCs) are frequently related to thermal stresses generated by a temperature gradient and its variation. In this study, a computational fluid dynamics (CFD) model is developed and further applied in full-size SOFC stacks, which are fully coupled and implemented for analysis of heat flow electrochemical phenomena, aiming to predict thermal stress distribution. The primary object of the present investigation is to explore features and characteristics of the thermal stress influenced by electrochemical reactions and various transport processes within the stacks. It is revealed that the volume ratio of the higher thermal stress region differs nearly 30% for different stack flow configurations; the highest probability of potential failure appears in the cell cathodes; the more cells applied in the stack, the greater the difference in the predicted temperature/thermal stress between the cells; the counter-flow stack performs the best in terms of output power, but the predicted thermal stress is also higher; the cross-flow stack exhibits the lowest thermal stress and a lower output power; and although the temperature and thermal stress distributions are similar, the differences between the unit cells are bigger in the longer stacks than those predicted for shorter stacks. The findings from this study may provide a useful guide for assessing the thermal behavior and impact on SOFC performance.

Coupled Electrochemical-Thermo-Stress Analysis for Methanol-Fueled Solid Oxide Fuel Cells

Abstract A three-dimensional model of a methanol-fueled solid oxide fuel cell (SOFC) that sufficiently considers the rib structure to understand the effects of operating conditions on a methanol-fueled SOFC is developed. The model considers the coupling of electrochemical reactions, mass transport, heat transfer, and thermal stress. The overall performance of the methanol-fueled SOFC is investigated under the influence of operating voltage, steam-to-carbon ratio, and porosity. The results indicate that as the operating voltage increases, the overall anode switches from exothermic to endothermic, and the stress of the anode first decreases and then increases. As the steam-to-carbon ratio increases, the overall temperature of the anode decreases. However, when the steam-to-carbon ratio is less than 1, the temperature at the inlet is lower than the ambient temperature. Meanwhile, the first principal stress on the anode increases as the steam-to-carbon ratio increases. Increasing the porosity reduces the length of the three-phase boundary, thereby decreasing the current density and the overall temperature and thermal stress on the anode. This study revealed the effects of operating conditions on the methanol-fueled SOFC, especially on the rib, and contribute to controlling the operant conditions for SOFC fueled by a mixture of steam and methanol.

Cation doping and oxygen vacancies in the orthorhombic FeNbO4 material for solid oxide fuel cell applications: A density functional theory study.

The orthorhombic phase of FeNbO4, a promising anode material for solid oxide fuel cells (SOFCs), exhibits good catalytic activity toward hydrogen oxidation. However, the low electronic conductivity of the material specifically in the pure structure without defects or dopants limits its practical applications as an SOFC anode. In this study, we have employed density functional theory (DFT + U) calculations to explore the bulk and electronic properties of two types of doped structures, Fe0.9375A0.0625NbO4 and FeNb0.9375B0.0625O4 (A, B = Ti, V, Cr, Mn, Co, Ni) and the oxygen-deficient structures Fe0.9375A0.0625NbO3.9375 and FeNb0.9375B0.0625O3.9375, where the dopant is positioned in the first nearest neighbor site to the oxygen vacancy. Our DFT simulations have revealed that doping in the Fe sites is energetically favorable compared to doping in the Nb site, resulting in significant volume expansion. The doping process generally requires less energy when the O-vacancy is surrounded by one Fe and two Nb ions. The simulated projected density of states of the oxygen-deficient structures indicates that doping in the Fe site, particularly with Ti and V, considerably narrows the bandgap to ∼0.5eV, whereas doping with Co at the Nb sites generates acceptor levels close to 0eV. Both doping schemes, therefore, enhance electron conduction during SOFC operation.

Electricity and hydrogen production by integrating two kinds of fuel cells with copper chlorine thermo-chemical cycle

An innovative cogeneration system based on a solid oxide fuel cell (SOFC) and copper chlorine cycle is being investigated. Instead of directly making electricity by any thermodynamic cycle or thermoelectric generator, the waste heat from SOFC should be used to make hydrogen through the copper-chlorine cycle (Cu–Cl). A portable polymer exchange membrane fuel cell (PEMFC) has been suggested due to its compatibility with portable and non-portable applications. The obtained results reveal that increasing the current density of SOFC results in higher methane consumption, output power, overpotentials, and hydrogen production. Furthermore, temperature variation does not have as much influence on power generation and efficiency as current density, where the system efficiency, when operating at 0.7 A/cm2 and SOFC operating temperature of 900–1200 K, varies between 40.4 % and 46.3 %. Regarding the methane flow rate, as it increases, the output power increases as well, but the efficiency falls. The system's greatest power output is 677.5 kW and occurs at a methane flow rate of 2.13 mol/s, although the system efficiency is just 39.7 % at that point. Most importantly, SOFC generates nearly 65 % of the total power, while PEMFC generates around 35 %. Therefore, the percentage of additional power that PEMFC can produce is around 55 %.

Techno-Economic and Environmental Analysis of a Hybrid Power System Formed From Solid Oxide Fuel Cell, Gas Turbine, and Organic Rankine Cycle

Abstract Distributed energy technology is an essential pathway for future advancements in the field of energy technology. In the present study, organic Rankine cycle (ORC) is integrated with solid oxide fuel cell (SOFC)-gas turbine (GT) hybrid power system. The conventional metrics employed for assessing the performance of SOFCs, gas turbines, and organic Rankine cycles, such as voltage and gross real efficiencies, have some limitations as indices of merit. Contemporary second law concepts and economic and environmental analysis have been used to enhance hybrid power system evaluation. R1233zd(E) has been selected as the ORC working fluid. The outcomes reveal that, under certain conditions, the present configuration may reach 55.67% energy efficiency and 53.55% exergy efficiency. Economic and environmental analysis shows that the hybrid system's total cost rate and Emissions of CO2 gas (EMI) under design conditions are 36.09 $/h and 355.8 kg/MWh, respectively. Thermodynamic evaluation of present SOFC-GT-ORC configuration shows 11.72% improvement in exergy efficiency compared to hybrid SOFC-GT cycle. Consequently, the hybrid SOFC-GT-ORC system is far better than the hybrid SOFC-GT system. In the future, other ORC fluids like R123, R601a, and R245fa can be used as ORC fluids.

Novel sr-doped NdMn0.5Cr0.5O3-δ electrodes for symmetrical solid oxide fuel cell

Solid oxide fuel cells (SOFCs) have emerged as promising energy conversion devices, offering high efficiency and environmental sustainability. Efficient electrode materials are crucial for the overall cell performance of SOFCs. Perovskite type Nd1-xSrxMn0.5Cr0.5O3-δ (x = 0.25, 0.5) (NSCM25, NSCM50) was synthesized via conventional solid-state reaction technique. Structural, thermal and electrochemical characterizations were performed using X-ray diffraction, thermogravimetric analysis, conductivity measurements, scanning electron microscope, thermal expansion coefficient analysis and impedance spectroscopy. Structural analysis revealed that both compositions exhibit orthorhombic symmetry in the Pbnm space group. Thermogravimetric analysis (TGA) indicated minimal weight changes in both pre-reduced and as-prepared samples. The electrical conductivities in air at 600 ℃ were found to be 1.69 S/cm for NSCM25 and 4.91 S/cm for NSCM50, with a decrease observed under reduced oxygen partial pressure. Polarization resistance (Rp) analysis was conducted on symmetrical cells composed of NSCM25|GDC|NSCM25, NSCM50|GDC|NSCM50, NSCM25|YSZ|NSCM25, and NSCM50|YSZ|NSCM50. At 900 ℃, the polarization resistances were 0.12 Ωcm2, 0.21 Ωcm2, 0.11 Ωcm2, and 0.67 Ωcm2, respectively. The results suggest that NSCM25 and NSCM50 hold promise as electrode materials for symmetrical solid oxide fuel cells (SSOFC) employing YSZ or GDC electrolyte.

Nanostructured Materials for Enhanced Performance of Solid Oxide Fuel Cells: A Comprehensive Review

Solid oxide fuel cells (SOFCs) have emerged as promising candidates for efficient and environmentally friendly energy conversion technologies. Their high energy conversion efficiency and fuel flexibility make them particularly attractive for various applications, ranging from stationary power generation to portable electronic devices. Recently, research has focused on utilizing nanostructured materials to enhance the performance of SOFCs. This comprehensive review summarizes the latest advancements in the design, fabrication, and characterization of nanostructured materials integrated in SOFC. The review begins by elucidating the fundamental principles underlying SOFC operation, emphasizing the critical role of electrode materials, electrolytes, and interfacial interactions in overall cell performance, and the importance of nanostructured materials in addressing key challenges. It provides an in-depth analysis of various types of nanostructures, highlighting their roles in improving the electrochemical performance, stability, and durability of SOFCs. Furthermore, this review delves into the fabrication techniques that enable precise control over nanostructure morphology, composition, and architecture. The influence of nanoscale effects on ionic and electronic transport within the electrolyte and electrodes is thoroughly explored, shedding light on the mechanisms behind enhanced performance. By providing a comprehensive overview of the current state of research on nanostructured materials for SOFCs, this review aims to guide researchers, engineers, and policymakers toward the development of high-performance, cost-effective, and sustainable energy conversion systems.

A thermodynamic approach to analyze energy, exergy, emission, and sustainability (3E-S) performance by utilizing low temperature waste heat in SOFC–CHP-TEG system

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.

Advanced design of cathode array protrusion structure of solid oxide fuel cell based on NSGA-II multi-objective optimization

As fuel cells gain widespread utilization, augmenting the power density and combination property of Solid Oxide Fuel Cells (SOFCs) has emerged as a pivotal area of research. This study introduces an innovative arrayed protrusion structure within the cathode flow channels of SOFCs to induce secondary flow. The influence of this arrayed structure on fuel cell combination property is meticulously analyzed through comprehensive numerical simulations. Furthermore, this paper employs the Response Surface Methodology to evaluate the synergistic effects of cathode operational conditions, particularly temperature, and arrayed structure parameters (including base width, height, and quantity) on SOFC performance. Correlations among these variables have been established to show synergistic associations between variables and performance index. The findings reveal that the inclusion of an arrayed structure in the cathode flow channels generates multi-directional vortices, thereby intensifying gas disturbance, facilitating reactant diffusion, and optimizing oxygen concentration distribution. This results in a marked enhancement of the fuel cell's overall performance. Among the operational parameters analyzed, temperature exerts the most substantial influence on power density, followed by protrusion height, base width, and number. Ultimately, using the Non-dominated Sorting Genetic Algorithm-II (NSGA-II), Pareto optimal solutions were derived, yielding a superior balance of higher power density and reduced pressure drop. Compared to the baseline, the power density in these Pareto optimal solutions saw an increase of 16.5% to 23.6%, while pressure drop escalated marginally by 1.5% to 8.9%.

A novel platinum modified barium zirconate-based electrolyte for enhanced solid oxide fuel cell performance

Pt modified BaZr0.76Y0.2Ni0.04O3 (BZYN) is fabricated and characterized as a stable electrolyte for proton-conducting solid oxide fuel cell (H-SOFC). The utilization of X-ray diffraction method (XRD) and transmission electron microscopy (TEM) enables the identification of the presence of platinum (Pt) in both the crystal lattice sites and the grain interface. This occurrence contributes to a reduction in grain boundary resistance. Consequently, this phenomenon improves the conductivity of the electrolyte. The electrochemical performance of the single cell with Pt-modified BZY electrolyte is improved by the reduction of ohmic resistance and enhancement of ion migration. This signifies a noteworthy advancement in the creation of more efficient and durable proton-conducting SOFCs.

Enhanced waste Plastics-to-Power in situ conversion through iron oxide as pseudofuel in solid oxide fuel cells

Waste plastics-to-power conversion via fuel cells is very attractive for its potential to be efficient and eco-friendly. Here we report a solid oxide fuel cell (SOFC) operating directly on waste polyethylene terephthalate (PET) with significantly improved performance due to the modification of anode with iron oxide (Fe2O3) that functions as pseudofuel in its reduced form (FeO). The pseudofuel performance, namely the discharge capacity of FeO, was improved significantly by optimizing the structure of Fe2O3, and owing to the synergistic interaction of FeO with the anodic materials, i.e. silver and gadolinia doped ceria. A mechanism is proposed to reveal the synergistic effect of these materials in the discharge process. The maximum discharge capacity of 340 mAh/g for FeO was obtained, approaching 91 % of the theoretical value. Based on the optimized pseudofuel, the electrochemical performance of SOFCs directly fueled by waste PET was markedly enhanced: The peak power density of the cell increased from 115 to 320 mW cm−2, and the electric energy output of the PET fuel did from 0.0018 to 0.26 Wh/g (140-fold more). This work shows that SOFCs with Fe2O3 modified Ag-based anode offer a promising platform for direct conversion of plastic waste to power in an efficient and green manner.

A Comprehensive Review of Thermal Management in Solid Oxide Fuel Cells: Focus on Burners, Heat Exchangers, and Strategies

Solid Oxide Fuel Cells (SOFCs) are emerging as a leading solution in sustainable power generation, boasting high power-to-energy density and minimal emissions. With efficiencies potentially exceeding 60% for electricity generation alone and up to 85% when in cogeneration applications, SOFCs significantly outperform traditional combustion-based technologies, which typically achieve efficiencies of around 35–40%. Operating effectively at elevated temperatures (600 °C to 1000 °C), SOFCs not only offer superior efficiency but also generate high-grade waste heat, making them ideal for cogeneration applications. However, these high operational temperatures pose significant thermal management challenges, necessitating innovative solutions to maintain system stability and longevity. This review aims to address these challenges by offering an exhaustive analysis of the latest advancements in SOFC thermal management. We begin by contextualizing the significance of thermal management in SOFC performance, focusing on its role in enhancing operational stability and minimizing thermal stresses. The core of this review delves into various thermal management subsystems such as afterburners, heat exchangers, and advanced thermal regulation strategies. A comprehensive examination of the recent literature is presented, highlighting innovations in subsystem design, fuel management, flow channel configuration, heat pipe integration, and efficient waste heat recovery techniques. In conclusion, we provide a forward-looking perspective on the state of research in SOFC thermal management, identifying potential avenues for future advancements and their implications for the broader field of sustainable energy technologies.

Direct ammonia SOFC – A potential technology for green shipping

International shipping carries about 90% of the global trade, thereby emitting significant amounts of greenhouse gasses by using fossil based fuels. Zero-emission technologies using green fuels are crucial to reduce the environmental impact of this important transport sector. Among the considered concepts is green ammonia in a solid oxide fuel cell (SOFC).The present study investigated SOFCs fueled with ammonia regarding cracking, electrochemical performance and durability. Ammonia cracking was for the first time directly measured over a planar, anode supported SOFC at open circuit voltage and during operation, as well as in presence of several balance of plant components. At temperatures around 700 °C, ammonia is significantly cracked when passing over hot metallic low surface area components (like Ni current collectors) even in the absence of the SOFC. The Ni/YSZ SOFC anode is active for the cracking as well. The area specific resistance of the SOFC is larger when using ammonia as compared to a H2/N2 mixture, due to two origins, (i) a decrease of the cell temperature due to the endothermal cracking, which leads to larger ohmic resistance and (ii) presence of unconverted ammonia, which increases the polarisation resistance in the low frequency region. Durability tests reveal increased cell voltage degradation when using ammonia fuel at 700 °C, mainly due to increase of the ohmic contributions. Micro structural analysis suggests nitridation as cause of this degradation. A stable SOFC operation is possible at 750 °C.

Surface oxide ion conduction of BaCe0.5Pr0.3Y0.2O3−δ thin film with complex mixed valence states

Solid oxide fuel cells (SOFCs), which operate in the medium temperature range from 300 °C to 500 °C, are effective in shortening startup time and reducing fuel gas. In order to realize a practical electrolyte with high oxide ion conductivity, we have investigated the ionic conductivity of c-axis oriented BaCe0.5Pr0.3Y0.2O3−δ (BCPY) thin films with complex mixed valence states prepared on Al2O3 (0001) substrates by RF magnetron sputtering. The amount of oxygen vacancies on the surface in the as-deposited BCPY thin film was evaluated to be ∼6.7% by X-ray absorption spectroscopy and defect chemical analysis. The as-deposited film exhibited relatively high ionic conductivity (σT) of more than 10−1 S·K cm−1 and activation energy (E A) of ∼0.57 eV in the medium temperature range by thermal activation process on the surface. The energy separation between the top of the VB and the Fermi level was much larger than E A, indicating that the BCPY thin film is a pure oxide ion conductor without the contribution of electron or hole carriers. These results indicate that the c-axis oriented BCPY thin film can be applied to electrolyte of SOFC operating in the medium temperature range.

A comprehensive survey of artificial intelligence-based techniques for performance enhancement of solid oxide fuel cells: Test cases with debates

Since installing solid oxide fuel cells (SOFCs)-based systems suffers from high expenses, accurate and reliable modeling is heavily demanded to detect any design issue prior to the system establishment. However, such mathematical models comprise certain unknowns that should be properly estimated to effectively describe the actual operation of SOFCs. Accordingly, due to their recent promising achievements, a tremendous number of metaheuristic optimizers (MHOs) have been utilized to handle this task. Hence, this effort targets providing a novel thorough review of the most recent MHOs applied to define the ungiven parameters of SOFCs stacks. Specifically, among over 300 attempts, only 175 articles are reported, where thirty up-to-date MHOs from the last five years are comprehensively illustrated. Particularly, the discussed MHOs are classified according to their behavior into; evolutionary-based, physics-based, swarm-based, and nature-based algorithms. Each is touched with a brief of their inspiration, features, merits, and demerits, along with their results in SOFC parameters determination. Furthermore, an overall platform is constructed where the reader can easily investigate each algorithm individually in terms of its governing factors, besides, the simulation circumstances related to the studied SOFC test cases. Over and above, numerical simulations are also introduced for commercial SOFCs’ stacks to evaluate the proposed MHOs-based methodology. Moreover, the mathematical formulation of various assessment criteria is systematically presented. After all, some perspectives and observations are provided in the conclusion to pave the way for further analyses and innovations.

Neural network-based modeling of solid oxide fuel cells for marine applications

As the solid oxide fuel cell (SOFC) experimental test is still quite cost-effective and time-consuming, there is a growing need for developing effective simulation tools to reduce the time and cost of the marine SOFC performance test and optimization. The present paper is aimed to study the modeling and simulation of marine solid oxide fuel cells by artificial intelligence method. A neural network based on a particle swarm optimization algorithm is used to establish a marine solid oxide fuel cell model for voltage/current characteristic analysis. The model is also compared with BP neural network and Hopfield neural network methods. The simulation results compared with experimental data show that the effectivity of the particle swarm optimization neural network algorithm is best, which can accurately predict the voltage/current characteristic curves of a SOFC under different fuel flow-air volume ratios. The model study can provide support for SOFC performance characteristics analyses and has significant potential in SOFC optimization applications.

Influence of the La0.2Sr0.7Ti0.95Ni0.05O3 (LSTN) Synthesis Method on SOFC Anode Performance

Solid oxide fuel cells are characterized by a high efficiency for converting chemical energy into electricity and fuel flexibility. This research work focuses on developing durable and efficient anodes for solid oxide fuel cells (SOFCs) based on exsolving nickel from the perovskite structure. A-site-deficient La- and Ni-doped strontium titanates (La0.2Sr0.7Ti0.95Ni0.05O3−δ, LSTN) were synthesized using four different techniques and mixed with Ce0.8Gd0.2O2−δ (GDC) to form the SOFC anode. The synthesis routes of interest for comparison included solid-state, sol-gel, hydrothermal, and co-precipitation methods. LSTN powders were characterized via XRD, SEM, TPR, BET and XPS. In situ XRD during reduction was measured and the reduced powders were analyzed using TEM. The impact of synthesis route on SOFC performance was investigated. All samples were highly durable when kept at 0.5 V for 48 h at 800 °C with H2 fuel. Interestingly, the best performance was observed for the cell with the LSTN anode prepared via co-precipitation, while the conventional solid-state synthesis method only achieved the second-best results.

Numerical investigation of the effect of functional layer thickness on solid oxide fuel cell performance

ABSTRACT In this 3D numerical study, the effects of cathode and anode functional layer thicknesses on the performance of solid oxide fuel cells under different operating parameters are analysed and elucidated. The performance of the model is evaluated using direct ammonia and an equivalent amount of hydrogen fuel with functional layers ranging from 0 to 50 μm. The findings unveiled that the cathode functional layer has a stronger influence on cell performance than the anode functional layer. The parametric analysis also showed that the effect of temperature gradually weakened with the increase of the cathode functional layer which is the exact opposite of what anode functional layers do. This gives more promising result for the cathode functional layer than the anode functional layer, especially for hydrogen-powered cells. However, the anode functional layer works best when green ammonia is supplied directly to the solid oxide fuel cell. In this regard, the 10 μm functional layers of the anode and cathode layers achieved the highest possible power density using ammonia and hydrogen fuels under similar operating conditions. This suggests that the anode layer has outstanding performance than the cathode counterparts for ammonia-fuelled cells and the layers of the cathode have better performance for hydrogen-fuelled cells. It is also observed that the performance of the cell is decreasing while the thickness of the functional layer is increasing particularly after 10 μm. The study also confirmed that solid oxide fuel cells with functional layers have outstanding performance over corresponding cells without functional layers. Thus, the finding of this study concluded that the functional layer thickness is strongly dependent on the types of fuel and electrodes used in the cells.