Search Results (1,502)

Energy policies and economies of scale have promoted the expansion of renewable energy sources, leading to the displacement of conventional generation units and a consequent reduction in system inertia. Low inertia amplifies frequency deviations in response to generation–load imbalances, increasing the risk of load shedding and service interruptions. To address this issue, this paper proposes a coordinated control strategy based on neuro-fuzzy networks, applied to a hybrid energy storage system (HESS) composed of batteries and supercapacitors. The controller is designed to simultaneously emulate virtual inertia and implement virtual droop control, thereby improving frequency stability and reducing reliance on spinning reserve. Additionally, a state-of-charge (SOC) management layer is integrated to prevent battery operation in critical zones, mitigating degradation and extending battery lifespan. The neuro-fuzzy controller dynamically coordinates the power exchange both among the energy storage technologies (batteries and supercapacitors) and between the HESS and the conventional generation unit, enabling a smooth and efficient transition in response to power imbalances. The proposed strategy was validated through simulations in MATLAB R2022b using a two-area power system model with parameters sourced from the literature and validated references. System performance was evaluated using standard frequency response metrics, including performance indicators (ITSE, ISE, ITAE and IAE) and the frequency nadir, demonstrating the effectiveness of the approach in enhancing frequency regulation and ensuring the operational safety of the energy storage system. Full article

The development of portable and wearable electronics has promoted the advancement of fiber supercapacitors (FSCs), but their low energy density still limits their application in flexible devices. Herein, we incorporated micron-sized graphene dispersions at varying concentrations into the polyaniline (PANI) precursor solution prepared via electrochemical polymerization and subsequently electrodeposited PANI/graphene composites onto the surface of carbon nanotube (CNT) fibers, ultimately obtaining fibrous PANI/graphene@CNT composite electrodes. This electrode material not only exhibits the superior electrochemical activity characteristic of conducting polymers synthesized by electrochemical polymerization but also possesses a relatively high specific surface area. Furthermore, we fabricated coaxial fiber supercapacitors using PANI/graphene@CNT composite fibers and CNT films as the positive and negative electrode materials, respectively. The maximum energy density and power density could reach 160.5 µWh cm⁻² and 13 mW cm⁻² respectively, proving its excellent energy storage and output capabilities. More importantly, the prepared CFASC device showed remarkable mechanical and electrochemical durability. Even after 3000 bending cycles, it retained 89.77% of its original capacitance, highlighting its promising applicability in the realm of flexible electronics. The resulting devices demonstrate excellent electrochemical performance and mechanical stability. Full article

Supercapacitors are widely recognized for their high power and energy densities. This study explores Fe_0.5Co_0.5S and its Ag-citrate composite for supercapacitors. Synthesized via coprecipitation, the composite was characterized using SEM and XRD, confirming its formation. Electrochemical tests revealed enhanced performance: CV oxidation current rose from 16.5 mA to 33.89 mA, GCD discharge time increased from 44.8 s to 129 s, and specific capacitance jumped from 37.3 F/g to 107.5 F/g—nearly threefold. EIS results also improved. The Ag-citrate addition boosted conductivity and capacitance, making the composite a promising supercapacitor material. Full article

Over the last few decades, polymer composites have been rapidly making inroads in critical applications of electrical storage devices such as batteries and supercapacitors. Structural supercapacitor composites (SSCs) have emerged as multifunctional materials capable of storing energy while bearing mechanical loads, offering lightweight and compact solutions for energy systems. This study investigates the functionalization of Bisphenol A-based thermosetting polymers with ionic liquids, aiming to synthesize dual-functional structural electrolytes for SSC fabrication. A multifunctional sandwich structure was subsequently fabricated, in which the fabricated SSC served as the core layer, bonded between two structurally robust outer skins. The core layer was fabricated using carbon fibre layers coated with 10% graphene nanoplatelets (GNPs), while the skin layers contained 0.25% GNPs dispersed in the resin matrix. The developed device demonstrated stable operation up to 85 °C, achieving a specific capacitance of 57.28 mFcm⁻² and an energy density of 179 mWhm⁻² at room temperature. The performance doubled at 85 °C, maintaining excellent capacitance retentions across all experimented temperatures. The flexural strength of the developed sandwich SSC at elevated temperature (at 85 °C) was 71 MPa, which exceeds the minimum requirement for roofing sheets as specified in Australian building standard AS 4040.1 (Methods of testing sheet roof and wall cladding, Method 1: Resistance to concentrated loads). Finite element analysis (FEA) was performed using Abaqus CAE to evaluate structural integrity under mechanical loading and predict damage initiation zones under service conditions. The simulation was based on Hashin’s failure criteria and demonstrated reasonable accuracy. This research highlights the potential of multifunctional polymer composite systems in renewable energy infrastructure, offering a robust and energy-efficient material solution aligned with circular economy and sustainability goals. Full article

Nanocomposites, which combine various nanomaterials, offer immense potential in the design of advanced materials for energy-related applications. These materials, engineered at the nanoscale, exhibit enhanced properties compared to their bulk counterparts, such as improved electrical conductivity, mechanical strength, and thermal stability. Nanocomposites have emerged as promising candidates for use in energy storage systems, including batteries and supercapacitors, by improving energy density, cycle life, and charge–discharge rates. In renewable energy technologies such as fuel cells, nanocomposites play a crucial role in enhancing efficiency and stability, which are vital for reducing costs and promoting the adoption of clean energy solutions. The unique properties of nanocomposites, such as high surface area and tunable composition, allow for the integration of multiple functionalities, making them ideal for multifunctional catalysts in energy conversion and environmental remediation. Additionally, nanocomposites enable the development of energy harvesting systems with improved performance and durability. These materials can be tailored by adjusting the composition of the nanomaterials, opening new opportunities for energy applications. The increasing research into nanocomposites continues to drive innovation in energy-related technologies, positioning them as a key enabler for sustainable energy solutions and future advancements in renewable energy systems. Full article

Polyaniline (PANI) nanofibers (NFs) were synthesized via two chemical oxidative polymerization approaches: a rapid mixing process and a conventional stirred tank method. PANI is a promising electrode material for supercapacitors due to its conductivity, stability, and pseudocapacitive redox behavior. The rapid mixing route proved especially effective, as fast polymerization promoted homogeneous nucleation and yielded thin, uniform, and interconnected NFs, whereas conventional stirring produced thicker, irregular fibers through heterogeneous nucleation. Structural characterization (FTIR, UV-Vis, XRD, XPS, TGA) confirmed that both samples retained the typical emeraldine form of PANI, but morphological analyses (SEM, BET) revealed that only the rapid process preserved nanofiber uniformity and porosity. This morphological control proved decisive for electrochemical behavior: symmetric supercapacitor devices fabricated from rapidly synthesized NFs delivered higher specific capacitances (378.8 F g⁻¹ at 1 A g⁻¹), improved rate capability, and superior cycling stability (90.33% retention after 3000 cycles) compared to devices based on conventionally prepared NFs. These findings demonstrate that rapid polymerization offers a simple and scalable route to morphology-engineered PANI electrodes with enhanced performance. Full article

Conductive polymer thin films have emerged as a versatile class of materials with immense potential in energy storage and conversion technologies due to their unique combination of electrical conductivity, mechanical flexibility, and tunable physicochemical properties. This review comprehensively explores the role of conductive polymer thin films in three critical energy applications: supercapacitors, batteries, and solar cells. The paper examines key polymers such as polyaniline (PANI), polypyrrole (PPy), and poly(3,4-ethylenedioxythiophene) (PEDOT), focusing on their synthesis techniques, structural modifications, and integration strategies to enhance device performance. Recent advances in film fabrication methods, including solution processing, electrochemical deposition, and layer-by-layer assembly, are discussed with regard to achieving optimized morphology, conductivity, and electrochemical stability. Furthermore, the review highlights current challenges such as scalability, long-term durability, and interfacial compatibility, while outlining future directions for the development of high-performance, sustainable energy systems based on conductive polymer thin films. Full article

We have demonstrated the fabrication of laminate composites with functional features to demonstrate energy storage capabilities. The present study investigates the surface modification of carbon fibers by coating dual materials of reduced graphene oxide (rGO) and cellulose-based activated carbon to enhance their energy storage capacitance for the development of structural supercapacitors. The dual coating on carbon fibers enabled a near 210-fold improvement in surface area, surpassing that of pristine carbon fibers. This formed a highly porous graphene network with activated carbon, resulting in a well-connected fiber–graphene-activated carbon network on carbon fibers. The electrochemical supercapacitor, fabricated from surface-functionalized carbon fibers, provides the best performance, with a specific capacitance of 172 F g⁻¹ in an aqueous electrolyte. Furthermore, the symmetrical structural supercapacitor (SSSC) device delivered a specific capacitance of 227 mF g⁻¹ across a wide potential window of 6 V. The electrochemical stability of the SSSC device was validated by a high capacitance retention of 97.3% over 10,000 cycles. Additionally, the study showcased the practical application of this technology by successfully illuminating an LED using the proof-of-concept SSSC device with G-aC/CF electrodes. Overall, the findings of this study highlight the potential of carbon fiber composites as a promising hybrid material, offering both structural integrity and a functional performance suitable for aerospace and automobile applications. Full article

As the energy transition advances toward a low-carbon economy, small- and medium-sized consumers are increasingly becoming active prosumers, capable of generating, storing, and managing their own electricity. However, the intermittent nature of renewable sources poses significant challenges in matching generation with consumption, making energy storage a key element for prosumer participation in smart grids. This work assesses the performance of various energy storage technologies suitable for prosumer applications, focusing on parameters such as efficiency, lifecycle behavior, and system integration. Lithium-ion batteries, supercapacitors, and hydrogen-based technologies were tested under real-world operating conditions within residential, commercial, and industrial scenarios. The results confirm that hybrid configurations deliver the most balanced performance, with supercapacitors improving short-term stability in commercial contexts and hydrogen storage enabling long-duration autonomy in industrial settings. In terms of battery state of charge, the experimental tests showed clear differences across prosumer types: in the residential case, it dropped to about 20–25% in the morning, but recovered to nearly full capacity by midday and stabilized at around 70–75% by the end of the day; in the commercial case, it fluctuated more widely, between roughly 18% and 100%, evidencing the highest stress on batteries; while in the industrial case, it reached 25–30% at peak demand, with hydrogen sustaining autonomy under extended load and ensuring greater long-term reliability. Overall, the findings reinforce the importance of tailored storage strategies to unlock the full potential of prosumers in smart grids. Full article

The integration of artificial intelligence (AI) and machine learning (ML) technologies is rapidly transforming the design, operation, and optimization of electric motorcycles. This review analyzes research published between 2015 and 2024, focusing on how ML algorithms enhance performance, energy efficiency, diagnostics, and charging strategies across four key domains: electric motors, energy storage, charging systems, and electronic components. The review highlights state-of-the-art solutions such as torque and range prediction using LSTM/GRU models, predictive maintenance via CNNs and autoencoders, energy flow control in hybrid battery–supercapacitor systems using reinforcement learning, and federated learning for privacy-preserving embedded applications. Comparative insights reveal quantifiable performance gains over traditional methods, while integrated frameworks are proposed for linking ML diagnostics, Vehicle-to-Grid (V2G) functionalities, and renewable energy integration. The paper concludes with targeted recommendations for future research, including lightweight edge-deployable models, Explainable AI for safety-critical applications, and the fusion of intelligent charging with eco-design principles, aiming to enable intelligent, sustainable, and high-performance electric motorcycle systems. Full article

Bamboo, as a rapidly renewable biomass material, has garnered significant attention in contemporary research due to its cost effectiveness as a viable source for supercapacitor electrode materials. However, untreated bamboo as an electrode material often leads to poor connectivity and uneven pore distribution. This study introduces a novel approach by using bamboo-derived biological carbon as a conductive substrate, subjecting it to carbonization through white-rot fungal pretreatment to enhance the pore structure and then loading it with nano-MnO₂ sheets via a hydrothermal process. The result is a binderless, self-supporting supercapacitor electrode material, denoted as MnO₂/hyphae/bamboo-derived carbon (HBC-2M). When compared to untreated bamboo carbon (HBC-0), HBC-2M exhibits an increased number of energy storage sites, enhanced electrolyte ion transport channels, and superior electrochemical performance. HBC-2M achieves a maximum mass-specific capacitance of 133.69 F·g⁻¹ and a maximum area-specific capacitance of 2367.95 mF·cm⁻² and retains approximately 87.46% of its capacitance after 2000 cycles. This research suggests a promising future for bamboo charcoal in supercapacitors. Full article

This study introduces a green method for converting waste polyvinyl chloride (PVC) into hierarchical porous carbon materials. By using CaCO₃ pre-activation to capture HCl and form meso/macroporous frameworks, followed by KOH activation to tune microporosity, high-surface-area porous carbon was successfully produced. The effects of KOH loading ratios (C-PVC:KOH = 1:1 to 1:3) on the primary activated carbon material were systematically investigated. It was found that a ratio of 1:2 (C-KOH-2) yielded optimal material properties, with a specific surface area of 1729 m² g⁻¹ and an oxygen doping content of 7.37%. Electrochemical measurements revealed that C-KOH-2 exhibited a high specific capacitance of 360.4 F g⁻¹ at 1 A g⁻¹, retaining 72.1% of its capacitance at 10 A g⁻¹. The symmetric supercapacitors achieved an energy density of 9.9 Wh kg⁻¹ at 125 W kg⁻¹, with 93.12% capacitance retention over 5000 cycles. This dual-purpose approach enables the upcycling of PVC waste while promoting the development of high-performance electrodes. Full article

This study examines the issue of wind power smoothing in renewable-energy-grid integration scenarios. Under the “dual-carbon” policy initiative, large-scale renewable energy integration (particularly wind power) has become a global focus. However, the intermittency and uncertainty of wind power output exacerbate grid power fluctuations, posing challenges to power system stability. Consequently, smoothing strategies for wind power energy storage systems are desperately needed to improve operational economics and grid stability. According to current research, single energy storage technologies are unable to satisfy both the system-level economic operating requirements and high-frequency power fluctuation compensation at the same time, resulting in a trade-off between economic efficiency and precision of frequency regulation. Therefore, hybrid energy storage technologies have emerged as a key research focus in wind power energy storage. This study employs the SE-SGMD method, utilizing the distinct characteristics of lithium batteries and supercapacitors to decompose frequency regulation commands into low- and high-frequency components via frequency separation strategies, thereby controlling the output of supercapacitors and lithium batteries, respectively. Additionally, the GA-GWO algorithm is applied to optimize energy-storage-system configuration, with experimental validation conducted. The theoretical contributions of this study include the following: (1) introducing the SE-SGMD frequency separation strategy into hybrid energy storage systems, overcoming the performance limitations of single energy storage devices, and (2) developing a power allocation mechanism on the basis of the inherent properties of energy storage devices. In terms of methodological innovation, the designed hybrid GA-GWO algorithm achieves a balance between optimization accuracy and efficiency. Compared to PSO-DE and GWO-PSO, the GA-GWO energy storage system demonstrates improvements of 21.10% and 17.47% in revenue, along with reductions of 6.26% and 12.57% in costs, respectively. Full article

This study focuses on developing FeNiS/PANI composites for supercapacitor applications, leveraging the individual benefits of iron–nickel sulfide (FeNiS) and polyaniline (PANI). FeNiS offers high electrical conductivity and energy density, while PANI contributes enhanced flexibility and pseudocapacitive behavior. The goal is to create a composite with superior electrochemical performance. Synthesis involved chemical oxidative polymerization for PANI and an in situ method for FeNiS, followed by integration. Characterization techniques like XRD, SEM, and EDS confirmed the successful formation and homogeneous elemental dispersion of the composite, showing that PANI formed an interconnected network that improved charge transport. Electrochemical analysis demonstrated significant improvements. Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) tests revealed that the FeNiS/PANI composite exhibited a doubled discharge time (159 s vs. 72 s for FeNiS) and a higher specific capacitance (113.5 F/g vs. 51.42 F/g). These results highlight the promise of FeNiS/PANI as an advanced material for efficient and sustainable energy storage. Full article

Supercapacitors are required to store energy from renewable resources to ensure a pollutant-free environment. To further encourage its study, researchers are interested in introducing green methods to produce electrode materials. Green synthesis is an innovative and emerging field because plant extracts are the best substitute for toxic chemicals. They are considered eco-friendly and cost-effective. In this work, two plant extracts, orange juice (ORJ) and lemon juice (LMJ), are used to synthesize the Sr_0.8Ce_0.2Fe_0.8Co_0.2O₃ perovskite using the auto-combustion method. The electrochemical performance of Sr_0.8Ce_0.2Fe_0.8Co_0.2O₃ made from LMJ and ORJ is compared to check their effectiveness. LMJ proved to be a better reducing agent than ORJ with a higher specific capacity of 300 C/g (544 F/g) at 1 A/g current density due to increased oxygen vacancies and surface area. These findings show that green-synthesized perovskites can be utilized in high-performance hybrid supercapacitor devices. Full article