Supercapacitor Energy Storage Devices Research Articles

A smooth method for primary frequency of wind turbine based on variable power point tracking and energy storage cooperative control

AbstractThe conventional deloading control has certain problems, such as low power generation efficiency and a small speed adjustment range. To improve the system's frequency quality and enhance the power grid's stability, this study comprehensively considers the effect of random source‐load power fluctuations on the system frequency. Moreover, this study proposes a smooth primary frequency control strategy for wind turbine based on the coordinated control of the variable power point tracking and supercapacitor energy storage. The impact of wind power fluctuations on the system frequency at different timescales for wind turbine is studied based on the historical data of wind power fluctuations in a strong wind meteorological cycle of a wind farm. The method determines the capacity of the energy storage device required for frequency smoothing at the optimal timescale. In combination with the required capacity of the wind turbine to participate in the system's primary frequency regulation, the supercapacitor energy storage device is optimally configured, and a set of supercapacitor energy storage device with the lowest cost under the highest charging/discharging efficiency is designed. Simulation and experimental results show that the primary frequency adjustment capability of the control strategy proposed in this study is significantly improved compared with the conventional primary frequency modulation control.

An ambipolar PEDOT-perfluorinated porphyrin electropolymer: application as an active material in energy storage systems.

The development of functional organic materials is crucial for the advancement of various fields, such as optoelectronics, energy storage, sensing, and biomedicine. In this context, we successfully prepared a stable ambipolar perfluoroporphyrin-based polymeric film by electrochemical synthesis. Our strategy involved the synthesis of a novel tetra-pentafluorophenyl porphyrin covalently linked to four 3,4-ethylenedioxythiophene (EDOT) moieties. The resulting monomer, EDOT-TPPF16, was obtained through a straightforward synthetic approach with a good overall yield. The unique molecular structure of EDOT-TPPF16 serves a dual function, with EDOT moieties allowing electropolymerization for polymeric film formation, while the electron-acceptor porphyrin core enables electrochemical reduction and electron transport. The electrochemical polymerization permits the polymer (PEDOT-TPPF16) synthesis and film formation in a reproducible and controllable manner in one step at room temperature. Spectroelectrochemical experiments confirmed that the porphyrin retained its optoelectronic properties within the polymeric matrix after the electrochemical polymerization. The obtained polymeric material exhibited stable redox capabilities. Current charge-discharge cycles and electrochemical impedance spectroscopy of the electrochemically generated organic film demonstrated that the polymer could be applied as a promising active material in the development of supercapacitor energy storage devices.

Experimental and theoretical insights into the supercapacitive performance of interconnected WS2 nanosheets.

Transition metal dichalcogenides (TMDs) are fascinating and prodigious considerations in the electrochemical energy storage sector because of their two dimensional chemistry as well as heterogeneous characteristics. Herein, we synthesized interconnected WS2 nanosheets by a hydrothermal method followed by sulphuration at 850 °C in an argon atmosphere. The ultrathin WS2 nanosheet array is endowed with an excellent specific capacitance of 74 F g-1 at the current density of 3 A g-1 up 7000 cycles. Moreover, a symmetric supercapacitor was fabricated using WS2 nanosheets, which provided the admirable high specific capacity of 6.3 F g-1 at 0.05 A g-1 with the energy and power density of 5.6 × 102 mW h kg-1 and 3.6 × 10 5 mW kg-1, respectively. Density functional theory (DFT) simulations revealed the presence of populated energy states near the Fermi level resulting in a high quantum capacitance value, which supports the experimentally achieved high capacitance value. The attained results recommend interconnected WS2 nanosheets as a novel, robust, and low-cost electrode material for supercapacitor energy storage devices.

One-step electrochemical synthesis of FTO/MnO2-graphene composite for electrochemical energy storage

The FTO/MnO2-Graphene composite was prepared using a one-step electrochemical approach employing chronoamperometry. Graphene was synthesized via electrochemical exfoliation and characterized using Raman spectroscopy and transmission electron microscopy (TEM).The prepared composite film exhibiting an extraordinary structure offers a large surface area provided with several channels to enhance the rapid diffusion of ions and electron transport owing to the grapheme sheets content. Various characteristics of the composite films have been investigated through X ray diffraction (XRD). Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM) and UV–Vis spectroscopy. To evaluate the electrochemical performance of the FTO/MnO2 and FTO/MnO2-GR films, cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge tests were conducted. The specific capacitance was found at 5 mV·s−1, to be 192.3 F g−1 with graphene and 73.5 F g−1 without. This increase in capacitance upon incorporating grapheme sheets suggests that FTO/MnO2-GR composite film would have many potential applications as suitable materials for supercapacitor electrodes and energy storage devices. The FTO/MnO2-GR in a asymmetric supercapacitor demonstrated an excellent reversible operation, delivering an energy density of 3 W h kg−1 at a specific power of 25 W/ kg. Furthermore, even after 1000 cycles, the FTO/MnO2-GR asymmetric supercapacitor retains an impressive 99 % of its capacitance.

Metal–Organic Framework Supercapacitors: Challenges and Opportunities

AbstractSupercapacitors offer superior energy storage capabilities than traditional capacitors, making them useful for applications such as electric vehicles and rapid large‐scale energy storage. The energy storage performance of these devices relies on electrical double‐layer capacitance and/or pseudocapacitance from rapid reversible redox reactions. Metal–organic frameworks (MOFs) have recently emerged as a new class of electrode materials with promising supercapacitor performances and capacitances that exceed those of traditional materials. However, the comparison of the supercapacitor performance of a porous carbon and a state‐of‐the‐art MOF highlights a number of challenges for MOF supercapacitors, including low potential windows, limited cycle lifetimes, and poor rate performances. It is proposed that the well‐defined and tuneable chemical structures of MOFs present a number of avenues for improving supercapacitor performance. Recent experimental and theoretical work on charging mechanisms in MOF‐based supercapacitors is also discussed, and it is found that there is a need for more studies that elucidate the charge storage and degradation mechanisms. Ultimately, a deeper understanding will lead to design principles for realizing improved supercapacitor energy storage devices.

Nitrogen-phosphorous co-doped porous carbon from cross-linked polymers for supercapacitor applications

Herein, we report co-doped porous carbon with nitrogen-phosphorous derived from cross-linked polyvinyl alcohol and polyvinylpyrrolidone (AC-PA/PP/AP-x) polymers synthesized using a simple single activation process. Diammonium hydrogen phosphate (AP) acting as nitrogen and phosphorous source was used to dope the cross-linked polymer precursors. The properties of the as synthesized carbon materials were analysed using the following techniques: scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS) mapping, Raman spectroscopy and nitrogen sorption isotherm. The optimized AC-PA/PP/AP-0.5 sample possess the highest porous surface properties i.e., specific surface area (2656 m2g−1), pore volume (1.08 cm3g−1) and micropore volume (0.99 cm3g−1). The sample also achieved a remarkable specific capacitance (252Fg−1) corresponding to a specific current of 1Ag−1measured within the presence of 2.5 M KNO3 aqueous electrolyte, in three electrode set-up. The constructed symmetric AC-PA/PP/AP-0.5//AC-PA/PP/AP-0.5 SC with a good electrical series resistance (ESR = 0.6 Ω), delivers a great specific energy (27.3 W h kg-1) and specific power (400 W kg-1) when monitoring at 0.5Ag−1using same electrolyte. Good capacitance retention of 90 % was obtained while charge-discharging (CD) the device for about 10,000 cycles at 5Ag−1. The CD cycling also yielded a coulombic efficiency of 99.8 %. Thus, this porous carbon produced via cross-linking and heteroatom doping, has a well-connected hierarchical porous structure that includes both micropores and mesopores. This structure is important for charge storage and transport. Therefore, the fabricated symmetric cell is a promising supercapacitor energy storage device, where a high power is requisite.

Spectroscopic analysis of plant trace element incorporated silver nanoparticles synthesis from Datura metel l.

Here in we report, silver nanoparticles (Ag NPs) prepared from leaf extract of Datura metel L. via green synthesis method. Datura metel L. is an herbal medicinal plant of solanaceae family. The as - prepared Ag NPs characterized employing UV-Vis spectrometer, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDAX) techniques. The appearance of Surface Plasmon Resonance (SPR) peak at 415 nm suggested that creation of Ag NPs in UV-Vis spectrum. XRD pattern showed face centered cubic crystal structure of Ag NPs with organometallic complex phase. Peaks in FTIR spectrum reveal the existence of biomolecules. SEM image illustrate their clastic rock morphology and EDAX profile authenticate the company of Ag and plant trace element. The Cyclic voltammetry (CV), Choronopotentiometry, and Electrochemical impedance spectroscopy (EIS) analysis were performed as prepared Ag electrode. The specific capacitance of 267.59 F/g at 0.5 A/g and cyclic retention of 83.7% after charge-discharge 5000 cycles are obtained. Hence this material could be utilized as Supercapacitor energy storage devices.

Supercapacitor Energy Storages in Hybrid Power Supplies for Frequency-Controlled Electric Drives: Review of Topologies and Automatic Control Systems

This article provides an overview of the use of supercapacitor energy storage systems in adjustable AC drives for various purposes. The structures of the power section of combined (hybrid) power supplies for vehicle electric drives (hybrid electric vehicles and public transport vehicles) and general-purpose electric drives of an industrial grade (cranes, freight, and passenger lifts) are given. This review focuses on the problems inherent in conventional solutions adopted in the implementation of the power section, as well as the effect that can be obtained when using supercapacitor energy storage systems in controlled electric drives. The topologies of reversible DC/DC converters for supercapacitor energy storage devices are considered with a comparative assessment of their advantages and disadvantages, as well as their areas of application. This paper provides an overview of the structures of automatic control systems for supercapacitor energy storage devices. The composition and principles of regulating variables, the types of regulators used, and the criteria for setting regulation systems are analysed.

Biosynthesis of zinc oxide-cobalt oxide nanocomposite as electrode material and its performance evaluation for the sustainable hybrid supercapacitor energy storage devices

Novel energy storage techniques and systems have gained increasing importance in recent times to overcome the variability in the output of non-dispatchable renewable energy sources. Supercapacitors are energy storage systems that have attracted considerable attention from various stakeholders. However, the performance of an effective supercapacitor energy storage system depends mainly on the electrochemical behavior of the electrodes, and the methods used to fabricate the electrode materials. Sustainable methods for the fabrication of electrode materials such as green synthesis have recently attracted researchers. In this work, a method is proposed to synthesize zinc oxide and cobalt oxide nanocomposite using green synthesis to take advantage of their superior electrochemical properties and stability. Evaluation of the morphological and electrochemical performance of the fabricated nanocomposite showed good results. Further, the electrode material fabricated using the synthesized nanocomposite has shown energy density values in the range of 3.8 Wh/kg to 9.54 Wh/kg for the power density values of the range 3000 W/kg to 375.3 W/kg for the different chosen current densities. A retention capacity of approximately 85% was observed even after 5000 cycles which is one of the most important features of supercapacitors. Thus, green synthesis with its intrinsic advantages over chemical methods is expected to be a promising approach for the fabrication of electrode materials for supercapacitors in sustainable energy storage applications in the future.

Preparation of polyaniline/porous carbon spheres derived from γ-cyclodextrin for supercapacitors

• PANI was successfully grown in situ on the surface of PCS derived from CD. • The products exhibit good specific surface area and high specific capacitance. • It indicates great potentials for high-performance supercapacitors. γ-Cyclodextrin (γ-CD) is a pollution free and renewable biomass carbon source. Porous carbon spheres (PCS) can be prepared by the soft template method and hydrothermal treatment of γ-cyclodextrin. By combining PCS and the conductive polymer polyaniline (PANI), a composite with good electrochemical energy storage can be obtained. The electrochemical properties of the PANI/PCS composite are studied. In the three-electrode system, the specific capacitance of PCS reached 110.0F·g −1 at 1 A·g −1 , whereas the specific capacitance of the PANI/PCS composite reaches a maximum specific capacitance of 339.6F·g −1 , which is a significant improvement of 208.7% compared to that of PCS. Therefore, PANI/PCS composites have broad application prospects in supercapacitor energy-storage devices.

Synthesis and characterization of sulfonated hafnium oxide nanoparticles for energy storage devices

• The sulfonated HfO 2 nanoparticles obtained by treating with sulfuric acid (H 2 SO 4 ). • When sulfonation particles size were reduced. • Low Ohmic resistance was obtained in sulfonated HfO 2. • High supercapacitor value exhibited S-HfO 2 (210 Fg −1 ) compare to HfO 2 (126 Fg −1 ). Metal oxide electrode material plays a vital role, particularly in supercapacitor applications and energy storage devices. The present study broadly focuses on the comparative research of the super-capacitive performance of hafnium oxide (HfO 2 ) and sulfonated hafnium oxide (S-HfO 2 ) nanomaterials. The simple precipitation technique has been used to synthesize HfO 2 nanoparticles. Subsequently, sulfuric acid (H 2 SO 4 ) has been used to functionalize the obtained HfO 2 nanoparticles. Afterward, the crystalline phases and orientation of nanoparticles has been analyzed using X-Ray diffraction (XRD), the presence of functional group and possible vibration frequency of the material can be identified by Fourier transform infrared (FT-IR) spectroscopy, crystal structures, and lattice imperfections of the synthesis material were found by High-resolution transmission electron microscope (HR-TEM). Consequently, the nanoparticles' structure, thickness, and elemental composition have been analyzed using the Field-Emission scanning electron microscope (FE-SEM) and Energy Dispersive X-ray spectroscopy (EDS) techniques. To gain the knowledge of supercapacitor behavior of prepared nanomaterial, electrochemical properties, and ion transfer characteristics were investigated by various experiments, namely, the cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD). Moreover, the internal resistances of the material (HfO 2 and S-HfO 2 ) were analyzed using Electrochemical Impedance Spectroscopy (EIS) technique. Both the nanoparticles showed a good improvement in specific capacitance. The supercapacitor values were measured for HfO 2 and S-HfO 2 electrodes, which exhibit a specific capacitance value 126.0 Fg −1 and 210.0 Fg -,1 respectively, at the scan rate of 5 mVs −1 . Hence, it is noted that Sulfonated HfO 2 nanoparticle enhances the specific capacitance and is used as a promising substance for the energy storage device. Besides, this finding benefits the new researchers in developing different kinds of sulfonated metal oxide nanomaterials for energy applications.

Constructing Flexible All‐Solid‐State Supercapacitors from 3D Nanosheets Active Bricks via 3D Manufacturing Technology: A Perspective Review

AbstractDue to the unique geometric characteristics and electronic structure of hierarchical 3D nanosheets, they show excellent electron migration rate, ultra‐high specific surface area, and reliable structural stability. Therefore, 3D nanosheets have great application prospects in the field of electrochemical energy storage. Supercapacitor has attracted extensive attention in recent years due to its merits of fast charge and discharge, long cycle life, safety, and stability. Flexibility, miniaturization, and intelligent integration are the development direction of supercapacitor energy storage devices. The emerging 3D printing technology, especially the ink direct writing mode, has greatly improved the design ability and control accuracy of device microstructures. Based on the research progress of 3D graphene nanosheets and 3D MXene nanosheets in the early stage of the authors’ or other teams, this paper proposes to use advanced 3D printing technology to realize the design of flexible all solid‐state supercapacitors by using 3D nanosheets active materials with high specific capacitance. The design methods of interdigital electrodes, multilayer skeleton electrodes and fiber electrodes by 3D printing technology and the performance evaluation of flexible supercapacitor are systematically analyzed. This perspective review aims to provide new conception and theoretical guidance for the design, preparation, and performance optimization of 3D nanosheets‐built materials by 3D printing for the practical application of flexible all‐solid‐state supercapacitor in the future.

Biomass‐Derived Carbon Quantum Dots‐Induced Self‐Assembly of 3D Networks of Nickel‐Cobalt Double Hydroxide Nanorods as High‐Performance Electrode Materials for Supercapacitors

AbstractThe nickel‐cobalt double hydroxide hybrid materials induced by biomass‐derived carbon quantum dots (CQDs) have a three‐dimensional network structure of cross‐linked nanorods. The results demonstrate that the functional groups on the CQDs derived from pomelo peel promoted the nucleation and confined the growth of nickel‐cobalt double hydroxide. The as‐synthesized NiCo‐LDH‐CQDs‐20 exhibits the high specific capacitance of 1814 F g−1 at 1 A g−1. When the current density is increased to 15 A g−1, the specific capacitance value remains 75.5 % of the initial one, which indicates that NiCo‐LDH‐CQDs‐20 has an extremely high‐rate performance. Furthermore, the asymmetric supercapacitor NiCo‐LDH‐CQDs‐20//AC provides a high energy density of 46.47 Wh kg−1 in 2 M KOH solution with a power density of 800 W kg−1 and maintains an initial specific capacitance of 82.7 % after 2000 cycles. Therefore, this study provides a promising approach for the development of anode active materials in supercapacitor energy storage devices.

Supercapacitors based energy storage system for mitigating solar photovoltaic output power fluctuations

PurposeNon-linear power–voltage characteristics of solar cell and frequently changing output due to variation in solar irradiance caused by movement of clouds are the major issues need to be considered in photovoltaic (PV) penetration to maintain the power quality of the grid. It is important for a PV module to always function at its maximum available power point to increase the efficiency and to maintain the grid stability. A possible solution to mitigate these generation fluctuations is the use of an electric double-layer capacitor or supercapacitor energy storage device, which is an efficient storage device for power smoothing applications. This study aims to propose a power smoothing control approach to smoothen out the output power variations of a solar PV system using a supercapacitor energy storage device.Design/methodology/approachTo extract the maximum possible power from a PV panel, there are several maximum power points tracking (MPPT) algorithms developed in literature. Fuzzy logic controller-MPPT method is used in this work as it is a very efficient and popular technique which responds quickly under varying ecological conditions, reduced computational complexity and does not depend on any system constraints. Fuzzy logic-based MPPT controller by Boost DC–DC converter is developed for operating the PV panels at available maximum power point. Fuzzy logic-proportional integral (PI) charge controller is implemented by Buck–Boost converter to provide the constant current and suitable voltage for supercapacitor and to achieve better power smoothing. PI charge controller is preferred in this work as it offers better outcomes and is very easy to implement.FindingsSimulation results conclude that the proposed power smoothing control approach can efficiently smooth out the power variations under variable irradiance and temperature situations. To confirm the accurateness of the proposed system, it is validated for poly-crystalline PV module and comparison of results is done by using different case study with and without the use of an energy storage system under change in irradiance condition. The proposed system is developed and examined on MATLAB/Simulink environment.Originality/valueThe performance comparison between PV power output with and without the use of a supercapacitor energy storage device under different Case Studies shows that the improved performance in smoothing of power output was achieved with the use of a supercapacitor energy storage device.

Electrodeposited MnS@Ni(OH)2 core-shell hybrids as an efficient electrode materials for symmetric supercapacitor applications

The usage of composites with chalcogenides and hydroxides are fascinated prodigious consideration for supercapacitor application. In this work, the layer by layer assembly of MnS@Ni(OH)2 core-shell hybrids were prepared by facile electrodeposition method and utilized as a binder-free electrode material for symmetric supercapacitor application. Systematic analyses have been done to confirms the formation and morphological features of MnS@Ni(OH)2 core-shell hybrids. The core-shell hybrids of MnS@Ni(OH)2 exhibits the redox behavior and delivered a high specific capacity of 2612 F g­1 at a current density of 1 A g­1 with excellent cycle stability of 88% capacity retention over 5000th cycle in 3 M KOH electrolyte. The delivered specific capacity is the highest among MnS and Ni(OH) based supercapacitors and also higher than various types of other metal oxide-based supercapacitors. Moreover, a sandwich-like solid-state symmetric supercapacitor was fabricated using MnS@Ni(OH)2 core-shell hybrid, and thus provided the specific capacity of 168.75 F g­1 at a current density of 1 A g­1 with the energy and power density of 60 Wh kg−1 and 800 W kg−1, respectively. The attained results recommended that the MnS@Ni(OH)2 core-shell hybrid has the probability to be applied as a novel, robust, and low-cost electrode material for supercapacitor energy storage devices.

Optimization of MnO2, NiO and MnO2@NiO electrodes using graphene oxide for supercapacitor applications

MnO2@GO, NiO@GO and MnO2@NiO@GO electrodes were hydrothermally fabricated for applications in supercapacitor energy storage devices. Because of its large surface area and low electrical resistance, graphene oxide (GO) was added to the nanocomposites during electrode fabrication. The mutual co-operation of diverse components and composites with GO increased the performance, longevity, and hardness of electrodes. The greatest specific capacitance measured by cyclic voltammetry (CV) at 10 ​mV/s scan rates and GCD at 1.0 A/g current density for MnO2@GO, NiO@GO, and MnO2@NiO@GO, respectively, was 652, 425, 985 and 773, 487, 1141 ​F/g for MnO2@GO, NiO@GO, and MnO2@NiO@GO. Performances of various electrodes clearly show that composites of two transition metal oxides/GO had better performance when compared to single transition metal oxide/GO and the addition of graphene oxide enhanced the supercapacitive performances of the electrodes.

One pot synthesis of tungsten oxide nanomaterial and application in the field of flexible symmetric supercapacitor energy storage device

At present, electronic markets aim to develop new energy storage devices which are lightweight, portable, and flexible. In the present study, a flexible as well as a light weight energy storage device has been fabricated using tungsten oxide material. By a simple and effective hydrothermal technique, highly crystalline monoclinic tungsten oxide nanomaterial has been synthesised and the electrochemical performance of this material for supercapacitor energy storage application were analysed. Structural, optical and morphological studies were conducted using X-ray diffraction technique, Raman spectroscopy, Fourier transform infrared spectroscopy, and FESEM analysis. The electrochemical performance studies are carried out in two electrode set up. The supercapacitor device exhibits a specific capacitance of 64 F g -1 at 5 mV s−1.

The Electrochemical Performance of Simple, Flexible and Highly Thermally Stable PVA-TiO2 Nanocomposite in an All-Solid-State Supercapacitor

The construction and constitution of an all-solid-state supercapacitor (SC) energy storage device is heavily reliant on key elements and factors, namely, the electrochemical, thermal and mechanical stability of distinctive materials, the method of electrode and electrolyte preparation, formation of cells and packaging, to highlight a few. In our report, the preparation of an all solid state supercapacitor based primarily on the flexible PVA/TiO2 nanocomposite polymer electrolyte membrane (NCPEM) that served as an electrolyte cum separator and the multi-walled carbon nanotube (MWCNT) used as electrodes, are detailed. Among the varied combinations of TiO2 nanofillers with PVA polymers, the combination of 3wt% TiO2 produced the best energy storage performance in two electrode configuration. PVA/3wt%TiO2 blend membranes provided excellent thermal stability (up to 280 °C), mechanical stability (up to 50.21 MPa) and an incredible electrochemical performance. Due to the superior ionic transport facilitated by the electrode-electrolyte interface, the SC attained a specific capacitance of 137.72 F/g and an energy density of 19.12 Wh/Kg. It also acquired a power density of 277.7 mW/Kg at a current density of 1 A/g and exceptional capacitance retention of 94.08% over 6000 cycles. In order to substantiate this concept, tests to probe the comparison in electrochemical performances between PVA/3wt%TiO2 membrane and the commercially available Nafion 112 membrane along with same MWCNT electrodes, were conducted.

Unveiling the structural, charge density distribution and supercapacitor performance of NiCo2O4 nano flowers for asymmetric device fabrication

The flower-like nano sized nickel cobalt oxide was successfully synthesized by facial hydrothermal method. Supercapacitor [NiCo2O4)||Activated carbon] asymmetric supercapacitor device (ASC) has been fabricated. The prepared self-assembled flower-like nanostructured NiCo2O4 nanomaterials were subjected to various analytical tools such as Powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR). Furthermore, the bond length and electron cloud density between the atoms were analyzed by maximum entropy method (MEM). The electrochemical studies were probed using Cyclic Voltammetry (CV), chronopotentiometry charge-discharge (CD) and electrochemical impedance spectroscopy (EIS) using electrochemical workstation (CHI6008e) instrument. The activated carbon was used as an anode electrode material for device fabrication. The maximum specific capacitance of NiCo2O4 NFs was achieved to be 1030 Fg−1 at 1 Ag−1 with good cyclic stability. The maximum specific capacitance of ASC device is 41 Fg−1 at 1 Ag−1. More interestingly, the maximum specific energy (10 W h kg−1) and specific power (2000 W kg−1) values are achieved for asymmetric supercapacitor energy storage device.

A New Generation of Nanocomposite Materials Based on Carbon and Titanium for Use in Supercapacitor Energy Storage Devices

In this paper, promising nanocomposite materials based on carbon and titanium are considered. It is shown that the use of a highly porous matrix is of particular interest. Materials based on such matrices have minimal weight and high strength characteristics. The paper also describes composites based on porous carbon fibers with metal oxides. The directions for producing composites can be divided into three types: matrix method, coating of finished nanoparticles with an inert shell, and the formation of nanoparticles and matrices in one process. The coating of nanoparticles with an inert shell prevents their oxidation and preserves the necessary magnetic properties. When using methods such as IR pyrolysis, arc evaporation third-party metal-carbon phases are formed that contaminate the resulting material. To avoid this, reducing agents are used, for example, hydrogen when coking nanoparticles in methane plasma current restores metal particles from its sol-gel and prevents them from reacting with carbon. However, with this method, it is difficult to control the particle size. Using a ready-made matrix allows us to control the size of the nanoparticles. However, this method uses high temperatures, and sometimes hydrogen, which complicates the production process. The main problem in the field of nanocomposites is the search for more technological, simple, cheap, and environmentally friendly methods for obtaining nanocomposites with high performance characteristics. The developed technology for forming the pore space of the initial carbon matrix does not have the above disadvantages. This technology has a simple, cheap, and environmentally friendly design; moreover high temperatures are not used in the process of producing nanocomposites and third-party metal-carbon phases are not formed. The resulting nanocomposite materials are used as electrodes for ultra-high-volume capacitor structures. When studying the capacitance and electrical characteristics of samples, it is found that the formation of metal on a porous carbon matrix can significantly reduce the internal resistance of the cell and increase the specific energy consumption.