Supercapacitor Technology Research Articles

Fuzzy logic-based Energy Management System (EMS) of hybrid power sources: Battery/Super capacitor for electric scooter supply

The use of electric motors instead of internal combustion engines has been increasing in the automotive industry, particularly over the past decade. Studies attempting to use electrical energy as the only source to obtain the required movement from the wheels have run into difficulties due to the limitations of electricity storage units. Li-ion batteries as a power source have shown some interesting characteristics, especially in electric vehicles, but there is still research for development in the storage device. Findings from this research recommend combining battery and supercapacitor technology to power an electric scooter. Both of these power sources are modulated for maximum efficiency in transferring energy to the motors. For this reason, a fuzzy logic-based control algorithm for energy management is developed to keep the battery and supercapacitor at their optimal states of charge (SOC), meet load demands during braking and counter-loading, and boost the energy system's independence. An electric scooter's performance under varying loads is simulated in MATLAB and Simulink to verify the effectiveness of the EMS. The simulation results findings validate the usefulness of the proposed approach and present the novel EMS as very good solution for energy management problem using the fuzzy logic expert system to take decision.

Ag2S-Ag2O-Ag/poly-2-aminobenzene-1-thiol Nanocomposite as a Promising Two-Electrode Symmetric Supercapacitor: Tested in Acidic and Basic Mediums.

A Ag2S-Ag2O-Ag/poly-2-aminobenzene-1-thiol (P2ABT) nanocomposite was prepared using the photopolymerization reaction using AgNO3 as an oxidant. The size of the nanocomposite was about 40 nm, in which the morphology was confirmed using TEM and SEM analyses. The functional groups of Ag2S-Ag2O-Ag/P2ABT were confirmed using FTIR; also, XRD confirmed the inorganic Ag2S, Ag, and Ag2O formation. This nanocomposite has great performance in supercapacitor applications, with it tested in acidic (1.0 M HCl) and basic mediums (1.0 M NaOH). This pseudo-capacitor has great performance that appeared through the charge time in an acid medium in comparison to the basic medium with values of 118 s and 103 s, correspondingly. The cyclic voltammetry (CV) analysis further confirmed the excellent performance of the supercapacitor material, as indicated by the large area under the cyclic curve. The specific capacitance (CS) and energy density (E) values (at 0.3 A/g) were 92.5 and 44.4 F/g and 5.0 and 2.52 W·h·Kg-1 in the acidic and basic mediums, correspondingly. The charge transfer was studied through a Nyquist plot, and the produced Rs values were 4.9 and 6.2 Ω, respectively. Building on these findings, our objective is to make a significant contribution to the progress of supercapacitor technology through a prototype design soon.

Vertical growth of compact and large-area MoS2 nanosheet arrays on Ti3C2Tx for efficient bifunctional electrochemical energy storage and hydrogen evolution

The developments in hydrogen evolution reaction (HER) and supercapacitor technologies for electrochemical energy storage and conversion have received considerable attention. Although MoS2 is electrochemically active for both HER and supercapacitors, limited active sites, slow ionic transport, and poor conductivity lead to its poor capacitance and electrocatalytic activity. Herein, hierarchical Ti3C2Tx/MoS2/Ti3C2Tx@CC (TMT@CC) composites were well-designed as electrodes for both HER and supercapacitors. Flexible TMT@CC electrodes with an area as large as ∼ 80 cm2 and optimal mass-loading of 17.9 mg cm−2 were achieved. The inner layer Ti3C2Tx in the composites provides ideal nucleation sites for the growth of MoS2 arrays, and the outermost Ti3C2Tx effectively anchors the vertically arrayed MoS2. The hierarchically vertical structure provides strong interfacial coupling and shortens ion diffusion paths, leading to high stability and fast ion/electron transport kinetics. Due to such a synergistic effect, the flexible binder-free TMT@CC electrodes exhibited high areal capacitance (5.06 F cm−2 at 5 mA cm−2) for supercapacitors and low overpotential (119 mV versus RHE at 10 mA cm−2) for HER catalyst. Furthermore, a high energy density of 0.125 mWh cm−2 at a power density of 1.5 mW cm−2 has been achieved from the TMT@CC-based symmetric supercapacitor. Our strategy can be expanded to other vertically arrayed hierarchical structures as electrode materials of efficient HER and supercapacitors.

Technical evaluation of hybrid super capacitor technologies for local energy communities

Renewable energy sources have demonstrated in recent years their ability to reduce the dependence on fossil fuels, contribute to the security of energy supply and play an important role in reducing greenhouse gas emissions. To benefit from the local use of renewable sources and energy efficiency in distributed systems, the concept of local energy communities is established. In local energy communities, new innovative technologies are combined, highlighting the role of energy storage, to provide greater autonomy to communities that adopt this model. Among energy storage, the use of batteries stands out, while lithium batteries are currently the most widely used for domestic and residential applications, as well as in local energy communities. This work describes the experimental evaluation of an innovative energy storage system for energy communities based on hybrid supercapacitors (HSC), focused on local energy communities, and its comparison with other well established storage technologies, such as lithium-ion batteries.

An Overview of the Emerging Technologies and Composite Materials for Supercapacitors in Energy Storage Applications.

Energy storage is one of the challenges currently confronting the energy sector. However, the invention of supercapacitors has transformed the sector. This modern technology's high energy capacity, reliable supply with minimal lag time, and extended lifetime of supercapacitors have piqued the interest of scientists, and several investigations have been conducted to improve their development. However, there is room for improvement. Consequently, this review presents an up-to-date investigation of different supercapacitor technologies' components, operating techniques, potential applications, technical difficulties, benefits, and drawbacks. In addition, it thoroughly highlights the active materials used to produce supercapacitors. The significance of incorporating every component (electrode and electrolyte), their synthesis approach, and their electrochemical characteristics are outlined. The research further examines supercapacitors' potential in the next era of energy technology. Finally, concerns and new research prospects in hybrid supercapacitor-based energy applications that are envisaged to result in the development of ground-breaking devices, are highlighted.

An approach to unify capacitance measurements of electric double layer capacitors using sinusoidal potential scan

Measuring supercapacitor capacitance is essential to understanding their electrical characteristics. However, different techniques can provide significantly different capacitance values. This discrepancy makes it difficult to compare results and communicate new research findings, hindering the progress of supercapacitor technology, particularly electric double layer capacitors (EDLCs). Voltammetry techniques often assume an ideal capacitor, while electrochemical impedance spectroscopy (EIS) recognizes the need to model the non-ideal electrode behavior with a constant phase element (CPE). Through comparison with the responses of two commercial EDLCs, this study confirms that the time domain responses of EDLCs should be modeled with CPE rather than a pure capacitor. The derived equations are then used to examine the effects of experimental conditions and the CPE exponent on capacitance measurements in cyclic voltammetry (CV). The study shows that estimated capacitances are affected by several experimental conditions, not only the scan rate, highlighting the need for an alternative approach to unify the capacitance measured using different analytical methods and measuring techniques. Therefore, this study proposes an alternative approach to estimate the capacitance of a CPE using a sinusoidal potential scan in voltammetric measurements. This approach not only equalizes the capacitance measured using different analytical methods and measuring techniques but also significantly reduces the number of experimental parameters affecting the calculated capacitance to just the frequency (or scan rate). The findings of this study offer valuable insights into the estimation of capacitance via various methods and have potential implications for improving the performance of electrochemical devices, particularly EDLCs, in the pursuit of a clean energy future.

Assessment of Battery–Supercapacitor Topologies of an Electric Vehicle under Real Driving Conditions

Road transport is shifting towards electrified vehicle solutions to achieve the Conference of the Parties of the United Nations Framework Convention on Climate Change (COP27) carbon neutrality target. According to life cycle assessment analyses, battery production and disposal phases suffer a not-negligible environmental impact to be mitigated with new recycling processes, battery technology, and life-extending techniques. The foundation of this study consists of combining the assessment of vehicle efficiency and battery ageing by applying supercapacitor technology with different topologies to more conventional battery modules. The method employed here consists of analysing different hybrid energy storage system (HESS) topologies for light-duty vehicle applications over a wide range of operating conditions, including real driving cycles. A battery electric vehicle (BEV) has been modelled and validated for this aim, and the reference energy storage system was hybridised with a supercapacitor. Two HESSs with passive and semi-active topologies have been analysed and compared, and an empirical ageing model has been implemented. A rule-based control strategy has been used for the semi-active topology to manage the power split between the battery and supercapacitor. The results demonstrate that the HESS reduced the battery pack root mean square current by up to 45%, slightly improving the battery ageing. The semi-active topology performed sensibly better than the passive one, especially for small supercapacitor sizes, at the expense of more complex control strategies.

Review of Flexible Supercapacitors Using Carbon Nanotube-Based Electrodes

Carbon nanotube (CNT)-based electrodes in flexible supercapacitors have received significant attention in recent years. Carbon nanotube fiber fabrics (CNT-FF) have emerged as promising materials due to their high surface area, excellent conductivity, and mechanical strength. Researchers have attempted to improve the energy density and rate performance of CNT-FF supercapacitor electrodes through various strategies, such as functionalization with conductive materials like MnO2 nanoparticles and/or incorporation of graphene into them. In addition, the utilization of CNTs in combination with thin metal film electrodes has also gained widespread attention. Research has focused on enhancing electrochemical performance through functionalizing CNTs with conductive materials such as graphene and metal nanoparticles, or by controlling their morphology. This review paper will discuss the recent developments in supercapacitor technology utilizing carbon nanotube-based electrodes, including CNT fiber fabrics and CNTs on thin metal film electrodes. Various strategies employed for improving energy storage performance and the strengths and weaknesses of these strategies will be discussed. Finally, the paper will conclude with a discussion on the challenges that need to be addressed in order to realize the full potential of carbon nanotube-based electrodes in supercapacitor technology.

In-situ-foaming synthesis of cheese-like Fe3S4/Ti3C2Tx electrode material with both high energy and power density for Al/Zn-ion supercapacitors

Although supercapacitor technology has been proposed as a promising new-generation energy means for its rapid charging speed and high operation safety, the shortcoming of low energy density has long been a big obstacle due to the low voltage window and storage capacity. In this study, a new kind of electrode material of Fe3S4/Ti3C2Tx has been proposed by a facile in-situ-foaming strategy through the reaction of Na2S with Fe(NO3)3. Herein, the byproducts of trace H2S and H2 gases were found to appear and expel, creating a lot of pores inside the Fe3S4/Ti3C2Tx composites with a cheese-like heterostructure. Therefore, the maximum specific capacity of Fe3S4/Ti3C2Tx-42% is measured up to 305.8 C g−1 at 2 A g−1, 3.4 times that of Fe3S4 and 5.9 times that of Ti3C2Tx. When Fe3S4/Ti3C2Tx-42% is assembled as a cathode for the Al-ion capacitors and Zn-ion capacitors, the devices both possess superior electrochemical performance. Especially for the Zn-ion capacitors, the device exhibits a high power density of 5500 W kg−1 at a maximum energy density of 61 W h kg−1 and a high stability after 10,000 cycles, showing a distinct advantage over previously reported literatures. Density functional theory (DFT) simulation and XPS analysis are used to validate the beneficial transformation mechanism of reactive sites, thus providing a novel idea for solving the poor structural stability of sulfide materials and MXene-based nanomaterials.

Polyindole Embedded Nickel/Zinc Oxide Nanocomposites for High-Performance Energy Storage Applications.

Conducting polymers integrated with metal oxides create opportunities for hybrid capacitive electrodes. In this work, we report a one-pot oxidative polymerization for the synthesis of integrated conductive polyindole/nickel oxide (PIn/NiO), polyindole/zinc oxide (PIn/ZnO), and polyindole/nickel oxide/zinc oxide (PNZ). The polymers were analyzed thoroughly for their composition and physical as well as chemical properties by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), and thermogravimetric analysis (TGA). The PIn and its composites were processed into electrodes, and their use in symmetrical supercapacitors in two- and three-electrode setups was evaluated by cyclic voltammetry (CV), galvanostatic discharge (GCD), and electrochemical impedance spectroscopy (EIS). The best electrochemical charge storage capability was found for the ternary PNZ composite. The high performance directly correlates with its uniformly shaped nanofibrous structure and high crystallinity. For instance, the symmetrical supercapacitor fabricated with PNZ hybrid electrodes shows a high specific capacitance of 310.9 F g-1 at 0.5 A g-1 with an energy density of 42.1 Wh kg-1, a power density of 13.2 kW kg-1, and a good cycling stability of 78.5% after 5000 cycles. This report presents new electrode materials for advanced supercapacitor technology based on these results.

A Reciprocal Charging Mechanism for Electric Vehicular Networks in Charging-Station-Absent Zones

The electric vehicles (EVs), as promising components of sustainable and eco-friendly transportation systems, are being widely adopted to reduce the consumption of fossil fuel and the pollution of environments. EVs are usually equipped with wireless communication modules to support the vehicle to vehicle (V2V) communications, and thus an electric vehicular network (EVN) is constituted. However, the electric energy of EVs is extremely limited, and some EVs are possible to exhaust their electric energy before reaching the destinations. More seriously, when the EVs travel into the zones without any charging stations, they cannot be timely charged. With the rapid developments of wireless charging technologies (such as magnetic resonance) and graphene supercapacitor technologies, the reciprocal charges between EVs become feasible, i.e., the EVs with insufficient energy (IEVs) can be charged by the EVs with surplus energy (SEVs). In this paper, the strategies of selecting the local-optimal SEVs for IEVs and rescheduling their travel routes are investigated, and a distributed Reciprocal Charging Mechanism (RCM) is proposed. Both mechanism analysis and simulation results demonstrate the performance superiority of RCM. Specifically, with the proposed reciprocal charging mechanism, IEVs can be charged by SEVs in a charging-station-absent zone, and the electric energy consumption can be approximatively minimized.

Comparison of Dynamic Response Characteristics of Typical Energy Storage Technologies for Suppressing Wind Power Fluctuation

The intermittence and randomness of wind speed leads to the fluctuation of wind turbine output power. In order to study the applicability of battery, super capacitor and flywheel energy storage technology in suppressing wind power fluctuation, this paper takes a 3 MW direct drive wind turbine as an example, and, through the establishment of a wind storage system model, the dynamic response characteristics and application effects of the three typical energy storage technologies to suppress the power fluctuation of the wind turbine under two wind speed fluctuation scenarios are simulated and studied, and the stability of output power is quantitatively analyzed. Results show that all the three energy storage systems respond well to power command curves, but when the wind power fluctuation is large, the flywheel energy storage has a better effect on suppressing the wind power fluctuation, which can suppress about 70% of the power fluctuation.

Oxygen-Vacancy Abundant Nanoporous Ni/NiMnO3/MnO2@NiMn Electrodes with Ultrahigh Capacitance and Energy Density for Supercapacitors.

High-performance energy storage devices (HPEDs) play a critical role in the realization of clean energy and thus enable the overarching pursuit of nonpolluting, green technologies. Supercapacitors are one class of such lucrative HPEDs; however, a serious limiting factor of supercapacitor technology is its sub-par energy density. This report presents hitherto unchartered pathway of physical deformation, chemical dealloying, and microstructure engineering to produce ultrahigh-capacitance, energy-dense NiMn alloy electrodes. The activated electrode delivered an ultrahigh specific-capacitance of 2700 F/cm3 at 0.5 A/cm3. The symmetric device showcased an excellent energy density of 96.94 Wh/L and a remarkable cycle life of 95% retention after 10,000 cycles. Transmission electron microscopy and atom probe tomography studies revealed the evolution of a unique hierarchical microstructure comprising fine Ni/NiMnO3 nanoligaments within MnO2-rich nanoflakes. Theoretical analysis using density functional theory showed semimetallic nature of the nanoscaled oxygen-vacancy-rich NiMnO3 structure, highlighting enhanced carrier concentration and electronic conductivity of the active region. Furthermore, the geometrical model of NiMnO3 crystals revealed relatively large voids, likely providing channels for the ion intercalation/de-intercalation. The current processing approach is highly adaptable and can be applied to a wide range of material systems for designing highly efficient electrodes for energy-storage devices.

High-performance hybrid supercapacitor-immobilized Wells-Dawson polyoxometalates on activated carbon electrodes.

The nanofabrication of electroactive hybrid materials for next-generation energy storage devices is becoming increasingly significant as supercapacitor (SC) technology develops rapidly. The present study utilizes activated carbon (AC) templates reinforced with Wells-Dawson polyoxotungstates (POMs) to produce nanohybrid electrodes for high-performance supercapacitors. This study analyzes Wells-Dawson polyoxotungstates (P2W18) for the first time integrated with AC, and its structural and electrochemical performances are discussed. First, the electrochemical performances of symmetric supercapacitors were characterized in an acidic aqueous electrolyte (0.5 M H2SO4). It was observed that a supercapacitor cell containing the 5 wt% AC-P2W18 hybrid symmetric displayed a noteworthy specific capacitance of 289 F g-1 and a remarkable energy density of 40 W h kg-1. Moreover, 5% AC-P2W18 symmetric supercapacitor cells showed 89% cyclic stability over 4000 cycles. Three LED lights were charged onto the electrode. The LEDs continued to illuminate continuously for red until 160 seconds, yellow until 20 seconds, and blue until 10 seconds after removing the electrode from the electrochemical workstation, demonstrating the device's power and energy density.

Unveiling the potential of nanosheet-based NiTe2@MnTe hollow nanospheres in hybrid supercapacitor technology

Nanosheets constructed NiTe2@MnTe hollow nanospheres are synthesized for hybrid supercapacitor.

Recent advances in energy storage with graphene oxide for supercapacitor technology

This review explores the potential of graphene oxide (GO) in enhancing the performance and energy storage capabilities as supercapacitors, where 2D GO nanosheets derived from pristine graphite, exhibit remarkable electrical conductivity, high surface area, and mechanical strength.

Recent advances in cerium oxide-based nanocomposites in synthesis, characterization, and energy storage applications: A comprehensive review

Since advancements in energy conversion technologies and energy storage devices, the use of supercapacitors has become more prevalent recently. Their high energy density, consistent cycle life, and extended lifetimes of supercapacitors have been thought to be their key benefits. The development of supercapacitor technology has also been greatly aided by sustainability nanotechnology. Cerium oxide (CeO2) is a type of ceramic material that is demonstrated as having a positive electrochemical behavior among a variety of widely used materials. A prospective active material for supercapacitor applications is CeO2, together with its nanostructured composite materials, which is the subject of extensive research. Recent developments in this field necessitated the requirement to develop an alternative, thus giving rise to the supercapacitor. Supercapacitors utilize the same fundamental formulas as normal capacitors. Those characteristics enable it to behave at densities of energy and power that are higher than that of battery and ordinary capacitors, respectively. Due to their unique physicochemical characteristics, rare-earth minerals have garnered a lot of research interest as electrode materials for supercapacitor applications. Therefore, in this review, cerium composite-based electrode materials, cerium oxides and composite, ceria nano enzyme behavior, and rare earth oxide have all been covered as far as energy storage device applications are concerned.

Recent Development of Transition Metal Oxide Bismuth Vanadate Electrode Materials for Supercapacitor Applications: A Review

During the last decade, the supercapacitor, a replacement that may someday replace batteries, has sparked increased interest in energy-storage applications. For environmental and financial reasons, electrode materials with high energy and power density, and other electrochemical stability are vital to completing this critical duty. Numerous investigations on metal-based compounds and their composites have been conducted. Bismuth materials and composites stand out because of their redox behaviour, environmental friendliness, low toxicity charge storage capacity, and increased interest in employing them as energy storage for supercapacitor technology. In this article, we provide an overview of research on bismuth materials and their composites with a focus on energy storage applications and, more importantly, a focus on the study of their super capacitive performance, including specific capacitance, cycle stability, energy density, power density, and respective potential window and current density, as well as other electrochemical parameters.

A unified framework for exploring hysteresis between charge and discharge processes in supercapacitors

In supercapacitor technology, the determination of the largest voltage range useable for the charge storage is a key parameter to optimize their energy. For this purpose, “acceptable” coulombic and energy efficiencies are commonly used as cut-off values to delineate a safe operational potential window in opening-window charge-discharge experiments. Because of the arbitrariness of such an approach, attempts have been made over the past three decades to rationalize the determination of the stability window, but differentiate between capacitive and faradaic currents remains challenging. Assuming that it’s better to examine what is lost during the charge period to investigate the degradation of electrochemical interfaces, part of the problem is that we have not the correct perspective on stability with coulombic and energy efficiencies, since they give an indication of the way in which performance are retained during the charge process, as they represent the capacitive fractions of the measured quantities. Here, we propose a new formalism based on non-capacitive fractions to focus on what is lost during the charge period, in order to place the heterogeneous kinetics of the electrochemical degradation processes at the center of the debate on stability of the electrode-electrolyte interfaces in supercapacitors.

Theoretical and Experimental Investigation of In Situ Grown MOF‐Derived Oriented Zr‐Mn‐oxide and Solution‐Free CuO as Hybrid Electrode for Supercapacitors

AbstractRecently metal‐organic framework (MOF) derived electrode materials have grown considerable research interest in the field of supercapacitor (SC) technology. Herein, MOF‐derived Zr‐Mn‐oxide is successively combined with solution‐free CuO nanowires not only to avoid the structural limitations of MOF but also to fabricate a positive‐negative hybrid electrode material. The MOF‐derived mixed metal oxide prepared through in situ fabrication allows the uniform and unidirectional growth of oriented Zr‐Mn‐oxide@CuO@Cu. The hybrid electrode exhibited over 100% stability after 20,000 cycles in a three‐electrode setup with a wide potential window range of 1.2 V (−0.6 to 0.6 V). Further, the obtained Zr‐Mn‐oxide@CuO@Cu hybrid electrode exhibited 14.1‐ and 5.5‐fold higher capacity over its MOF‐derived Zr‐Mn‐oxide counterpart (−0.6 to 0.1 V) and CuO (0.0 to 0.5 V), respectively. Additionally, the hybrid device with hybrid Zr‐Mn‐oxide@CuO@Cu as the positive electrode and reduced graphene oxide as the negative electrode also displayed promising energy and power densities. Furthermore, density functional theory calculations are employed to study the hybrid electrode material's properties. Overall, the unidirectional and vertically aligned MOF‐derived Zr‐Mn‐oxide@CuO@Cu hybrid electrode material with notable electrochemical performance can be useful for the fabrication of next‐generation supercapacitor electrodes.