Supercapacitor Energy Storage Research Articles

Coordinated control of wind farm and supercapacitor energy storage system for dynamic performance reinforcement of multi-area power systems

Coordinated control of wind farm and supercapacitor energy storage system for dynamic performance reinforcement of multi-area power systems

Efficient faradaic supercapacitor energy storage using redox-active pyrene- and benzodithiophene-4,8-dione-tethered conjugated microporous polymers

Redox-active pyrene- and benzodithiophene-4,8-dione-tethered conjugated microporous polymers have been developed for high-performance faradaic supercapacitor energy storage.

Online SOC Estimation of Supercapacitor Energy Storage System Based on Fractional-Order Model

Fast and accurate estimation of state of charge (SOC) of supercapacitors is essential for the safe and reliable operation of energy storage systems. However, existing SOC estimation methods are based on the integer-order model of supercapacitors and do not take into account the fractional-order characteristics of supercapacitors. Hence, the accuracy of SOC estimation results usually ignores the impact of modeling and relies on the correction effect of the algorithm. In this paper, a supercapacitor energy storage system is firstly established for fractional-order modeling and fractional-order SOC estimation of supercapacitors. Next, a Kalman filter is devised to track the SOC of supercapacitors in real time, and it can correct the estimation results online. Finally, experiments under different working conditions are conducted to demonstrate the effectiveness of the proposed fractional-order modeling and SOC estimation scheme. Compared with the data obtained by the traditional integer-order method, the accuracy of the proposed fractional-order method is higher, and the mean relative errors are less than 5%. With the online correction of the Kalman filter, the maximum errors under different working conditions are limited to 1.3%.

Post-modified biomass derived carbon materials for energy storage supercapacitors: a review

A strategy to improve the performance of biochar materials for supercapacitors by preparation and modification methods.

Colloidal methods for the fabrication of Mn3O4-graphene film and bulk supercapacitors

Composite Mn3O4-graphene electrodes are fabricated by different colloidal processing methods, such as screen printing (SP), electrophoretic deposition (EPD) and slurry impregnation (SI) for energy storage in thin film and bulk supercapacitors (SCs). Good capacitive behavior of electrodes is linked to beneficial effect of current collectors and advanced colloidal processing. The results presented stress the importance of poly[1-[4-(3-carboxy-4-hydroxyphenylazo) benzenesulfonamido]-1,2-ethanediyl, sodium salt] (PAZO), which is used as a versatile co-dispersing, charging, binding and film forming agent for Mn3O4 and graphene. The effect of PAZO is linked to aromatic structure of its chelating monomers, which facilitate the fabrication of advanced inks for SP, suspensions for EPD and concentrated slurries for SI. Good capacitive behavior of thin film and bulk electrodes is achieved at low impedance. The properties of the SC electrodes make them promising for energy storage.

Biodegradable poly-ε-caprolactone based porous polymer electrolytes for high performance supercapacitors with carbon electrodes

Herein, we report porous polymers electrolytes (PPEs), composed of a biodegradable polymer poly-ε-caprolactone (PCL), activated with organic liquid electrolyte (ethylene carbonate (EC)/propylene carbonate (PC)/NaClO4) and an ionic liquid (IL)-incorporated electrolyte (1-ethyl-3-methylimidazolium trifluoromethane-sulfonate (EMITf)/Na-trifluoromethane sulfonate (NaTf). The porous polymeric membranes are prepared via a simple, one step immersion precipitation method, which provide channels for ionic transport. Morphological/structural, thermal and electrochemical studies on PPEs exhibit excellent flexibility, good porosity (∼80%), high (∼90%) liquid electrolyte uptake and high room temperature ionic conductivity (1.8–1.9 × 10−3 Scm−1) with wide electrochemical stability window (>5.0 V). Quasi-solid-state carbon supercapacitors/electrical double layer capacitors (EDLCs) are fabricated from symmetrical activated carbon (AC) electrodes (derived from a waste-biomass, sugarcane bagasse), separated by PPE-films. The supercapacitor based on IL-incorporated PPE exhibits higher specific capacitance (∼170 F g−1) and specific energy (∼34 Wh kg−1) compared to the device based on organic solvents-based PPEs (∼130 F g−1 and ∼24 Wh kg−1, respectively). Substantial energy storage in supercapacitor is evident from the glow of LED (35–50 mW) for longer duration. The device demonstrates stable performance up to ∼10,000 charge-discharge cycles with ∼15% initial capacitance fading and ∼100% Coulombic efficiency.

Bidirectional Interleaved DC–DC Converter for Supercapacitor Energy Storage Integration with Reduced Capacitance

This paper analyzes the control method of a multiphase interleaved DC–DC converter for supercapacitor energy storage system integration in a DC bus with reduced input and output filter size. A reduction in filter size is achieved by operating only in modes with duty cycles that correspond to smaller output current ripples. This leads to limited control of the charging and discharging process of the supercapacitor energy storage system. Therefore, a detailed analysis of the optimal charging strategy is provided in this paper for interleaved converters with different numbers of phases. The results show that such control can be used, albeit with some percentage loss in efficiency. Experimental results are presented in this paper to verify the theoretical results.

MXene-based nanomaterials for supercapacitor applications: New pathways for the future

MXenes have captivated investigators in methodical and technical areas towards different implementations, such as energy storage appliances, supercapacitors (SCs) and elastic batteries. The utilization of pristine MXenes and their nanomaterial in multiple types of SCs is cumulative due to their outstanding automatic, physicochemical, optical, electric, and electrochemical effects. Due to their exceptional electric performance, better mechanical strength, different practical clusters, and ample interlayer space, MXene-based nanomaterials (NMs) have demonstrated binding energy-storage capacity. In this review article, we have shown the timelines and progress in the synthesis methods over time and applications of MXene-based nanomaterials (NMs) in supercapacitors (SC). Lastly, we have concluded the theme with the future outlook in this field.

Preparation of nickel/copper sulfides from metal-organic frameworks. Applications to energy storage in a symmetric supercapacitor and electrocatalytic methanol oxidation

A hybrid of nickel and copper sulfides was synthesized by using metal-organic frameworks. The prepared composite (Ni3S2/CuxS) was then mixed with multi-walled carbon nanotubes to form MWCNTs@Ni3S2/CuxS. Several methods were used for characterization of the prepared composite. Electrochemical studies showed a great improvement in capacitive properties of graphite foil (GF) when modified by MWCNTs@Ni3S2/CuxS. In a three-electrode system, the specific capacitance was estimated from galvanostatic charge-discharge experiments to be 1388.7 F g−1 at a current density of 1 A g−1 with cycling stability of ∼ 100% (10,000 cycles). In two electrode system (symmetric supercapacitor, SSC), a wide working voltage range (2.4 V) was obtained in aqueous alkaline solution. Moreover, MWCNTs@Ni3S2/CuxS showed great electrocatalytic effect in methanol oxidation reaction (current density 346.7 mA cm−1 in methanol, 0.5 M). Chronoamperometric oxidation of methanol on MWCNT@Ni3S2/CuxS/GCE showed a current lose< 16% after 14,000 s (∼ 4 h). Chronopotentiometry at a constant current density (22.3 mA cm−2) showed a highly stable potential after 14,000 s (drift<8%). The excellent capacitive and electrocatalytic properties of MWCNTs@Ni3S2/CuxS were attributed to deposition of metal sulfides on metal-organic frameworks which prevented their agglomeration, and effective synergy among Ni3S2, MOF-derived-CuxS and MWCNTs.

Energy management of PV wind based microgrid with hybrid energy storage systems

Power demand all around the world is increasing day by day and conventional energy sources are getting depleted. In order to meet the power demand and to reduce the carbon emission caused by the conventional energy sources, alternate renewable energy sources are important. wind and solar are two reliable energy sources among the various renewable energy sources. In this proposed paper wind and photovoltaic (PV) energy-based direct current (DC) microgrid is proposed with super capacitor and battery hybrid energy storage systems. Constant DC link voltage is the replication of energy balance in DC microgrid. The main goal of the proposed microgrid energy management algorithm is to maintain the constant DC link voltage irrespective of the intermittent nature of the renewable energy sources, load variations and under fault conditions. Energy management system is designed such that battery energy storage system handles the average power requirements and super capacitor handles the transient power requirements caused by the load, renewable energy variation and also caused due to fault conditions. The proposed system improves battery life along with effective DC link voltage regulation. The proposed control algorithm of energy management is compared with conventional energy management system in MATLAB/Simulink and presented for various studies.

Capacitive electrodes based on a combination of activated carbon and graphene

As an important element of energy storage systems, Supercapacitors are energy storage devices with high power density. In order to ensure their high efficiency, along with a high specific capacitance, it is important to lower their series resistance. Carbon materials with a high specific surface area have been widely used as potential electrode material for supercapacitors, however their insufficiently low electrical resistivity limits the energy and power density of the device. Therefore, for optimizing the energy storage and power capability of supercapacitors, development of composite materials electrodes with optimized properties and low electric resistance is crucial. In this article, composite electrodes based on a combination of activated carbon and graphene are obtained and their properties are investigated. The capacitive performance of the composite electrodes is tested in an electrochemical cell and their advantage ] for lowering the electrical resistance of the device is shown.

Graphene-based composites for supercapacitors

Smart devices that are portable and wearable have advanced significantly over the years. Further research on compatible storage devices with tiny, light and flexible properties is required to make wearable electronic devices more versatile, lightweight, smart, and commercially viable. Because of their advantages of having a high-power density, long cycle longevity, superior mechanical strength, good safety, and ease of assembly, supercapacitors have sparked a great deal of interest. Nevertheless, if the conventional supercapacitor is distorted by an external force, the power storage qualities would be significantly diminished or perhaps even eliminated. The primary component of capacitors is the electrode material, hence it is essential to produce extremely flexible electrode materials with superior energy-storage capabilities. This study introduces the supercapacitor energy storage theory and the current state of graphene applications in flexible supercapacitors. Additionally, a succinct summary of the research on pseudo, double-layer, and asymmetric capacitors is provided. Future progress and the difficulties that flexible supercapacitor electrode materials still confront are explored.

Chemical Synthesis of Bismuth Oxide and Its Ionic Conversion to Bismuth Sulphide for Enhanced Electrochemical Supercapacitor Energy Storage Performance

Successive ionic layer adsorption and reaction (SILAR)-based room-temperature (27 °C) chemical synthesis of bismuth oxide (Bi2O3) and its ionic conversion to bismuth sulphide (Bi2S3) has been performed and reported in the present study. A chemical conversion of the bismuth oxide to the bismuth sulphide has been confirmed using changes in the structure, phase, surface elementals , and surface area measurement studies. Both bismuth oxide and bismuth sulphide electrode materials are envisaged in electrochemical measurements wherein, the later has evidenced an enhanced electrochemical performance over the prior. The cycling stability of the Bi2S3 (91% after 2000 cycles) electrode material is also better than the Bi2O3 (87% over 2000 cycles). The as-assembled Bi2S3//Bi2S3 symmetric electrochemical supercapacitor device has adduced 75.3 Wh kg−1 and 749.8 W Kg−1energy and power densities, respectively with nearly 88.8% capacitance retention efficacy even over 2000 redox cycles measured at 10 A g−1. The commercial potential of the Bi2S3//Bi2S3 has been tested by powering the display panel “CNED” consisting nearly 42 LEDs with a full-light intensity.

FeTe:Fe2TeO5 nanodots embedded MWCNTs: Nanocomposite electrode towards supercapacitor application

BackgroundFeTe:Fe2TeO5 nanodots encapsulated MWCNTs as a nanocomposite is a new hybrid electrode material tested for supercapacitor energy storage application for the first time. MethodFor the deposition of FeTe:Fe2TeO5 over MWCNTs simple, inexpensive, binder free and low-cost and thin-film method named successive ionic layer adsorption and reaction (SILAR) was used. Significant findingsFeTe:Fe2TeO5 nanodots encapsulated MWCNTs as a nanocomposite have been accomplished with the aid of sequential growth controlled chemical method. Mixed phase of iron telluride consisting of FeTe (Tetragonal) and Fe2TeO5(Monoclinic) has been well analyzed through structural studies. Due to growth of nanodots as seen through SEM images have been responsible to enhance surface area of MWCNTs/FeTe:Fe2TeO5 than that of bare FeTe:Fe2TeO5 supported by BET analysis. Oxidation states of mixed elements have been well confirmed through XPS studies. These characterization results of the electrode supporting for electrochemical supercapacitor application and hence, analyzed through electrochemical investigation inclusive of CV, GCD, EIS and electrochemical capacitance retention. Interestingly, MWCNTs/FeTe:Fe2TeO5 nanocomposite yields remarkable capacitance of 773.69 F/g at 3 mV/s, with an energy density of 8.19 Wh/kg and power density of 108 W/kg at current density of 0.8 mA/cm2. Electrodes good cyclic stability (capacitive retention) of 95% at 5000 CV cycles explores its candidature for future energy storage applications.

Assessment of supercapacitor performance in a hybrid energy storage system with an EMS based on the discrete wavelet transform

When battery and supercapacitor (SC) Energy Storage Systems (ESSs) coexist in electric vehicles, energy management is imperative to ensure efficient power distribution based on the strengths and weaknesses of each ESS. The decoupling of highly dynamic power demands into components that match the dynamic nature of each ESS is essential. The Discrete Wavelet Transform (DWT) has been widely recommended for this purpose as part of real time energy management systems. However, due to DWT signal processing, delays in the frequency components can undermine the benefits of hybridization. This paper analyses the contribution of the SC to alleviate the battery when the DWT is used with and without time delay compensation using future demand prediction. Four different implementation strategies for a DWT based EMS have been evaluated using different metrics to quantify energy circulation and SC assistance during acceleration and braking. Simulation results using urban and highway driving cycles, show that obtaining the SC current reference as the difference between the real time current demand and the DWT low frequency component enhances SC assistance during acceleration and braking at the expense of higher energy circulation. The complexity added by future demand prediction does not reap SC performance benefits.

Modified CNTs interfacial anchoring and particle-controlled synthesis of amorphous cobalt-nickel-boron alloy bifunctional materials for NaBH4 hydrolysis and supercapacitor energy storage

The advantage of composites comes from the synergy between different material, that is, the engineering of interface effects between them. Well-developed surface effects between the materials help to maximize the properties and improve the stability of the composite. Herein, CoNiB@ca-CNTs composites were successfully prepared through a simple wet chemical reduction method by reducing the metal ions pre-anchored on the surface of carboxylated modified CNTs. Co0.25Ni0.75B@ca-CNTs composite were used as electrode materials for supercapacitor. It provides high specific capacitance (2078 F g−1 under 1 A g−1), outstanding rate performance (1802 F g−1 under 10 A g−1), and good cycling stability (87.8% retention rate at 5000 cycles). The constructed Co0.25Ni0.75B@ca-CNTs//AC (activated carbon) asymmetric supercapacitor obtained 180.3 F g−1 under 1 A g−1. It has an energy density of 67.4 Wh kg−1 at 400.4 W kg−1 and good stability (84.1% retention at 5000 cycles). In addition, Co0.75Ni0.25B@CNTs was used as catalyst with excellent catalytic activity for the hydrolysis of NaBH4, with hydrogen production rates of 6245.75 mL min−1 gcatalyst−1 and 18135.16 mL min−1 gCo,Ni−1 at 25 °C and low activation of 28.67 kJ mol−1. It has good catalytic stability remaining 72.6% after 10 catalytic hydrolysis cycles. The results demonstrate that CoNiB@ca-CNTs exhibit excellent performance and stability in the field of supercapacitors and hydrogen production from NaBH4 hydrolysis. This work has a good inspiration for the development of bifunctional composite materials in the future.

Nanocarbon of moderate microporosity doped with oxygenate redox pairs to achieve superior gravimetic/volumetric supercapacitor performances

In the selection of carbon-based electrode materials for supercapacitive energy storage, it is hard to get one that is high in both gravimetric and volumetric performance because there is a trade-off between them. In the presented work, microporous carbon materials denoted herein as MICx were synthesized through catechol polymerization in the presence of molten FeCl3. As complexing agent, the iron species coordinate with catechol oligomers, functioning as template as well as catalyst in the synthesis of the microporous carbon. The in situ formation of micropores and carbonaceous skeleton is induced by the carbonyl/hydroxyl redox pairs upon catalytic graphitization during carbonization. The derived nanocarbons have high microporosity (70.6 %–79.2 %) and rich oxygenate functionalities (carbonyl: 3.3–4.0 atom% and hydroxyl: 2.5–4.2 atom%). The FeCx materials are high in faradaic activity. For example, the FeC873-based electrode displays excellent supercapacitor performances: capacitance of 440F/g@1.0 A/g (equivalent to 537F/cm3@1.0 A/g) and 289F/g@20 A/g (equivalent to 353F/cm3@20 A/g), large energy density of 25.5 Wh/kg@900 W/kg (equivalent to 31.1 Wh/L@1098 W/L), and good cycling stability (ca.100 % capacitance retention after 20 000 continual charge/discharge cycles).

Facile Preparations of Electrochemically Exfoliated N-Doped Graphene Nanosheets from Spent Zn-Carbon Primary Batteries Recycled for Supercapacitors Using Natural Sea Water Electrolytes

A single production of nitrogen-doped graphene nanosheets was developed in this present work from a spent Zn-C primary battery. The electrochemically exfoliated nitrogen-doped graphene nanosheets (EC-N-GNS) was applied in supercapacitor symmetric devices. As-prepared EC-N-GNS was utilized for a symmetric supercapacitor with natural seawater multivalent ion electrolyte. The recycling of graphite into nitrogen-doped graphene was characterized by X-ray diffraction and RAMAN spectroscopy. The few-layered morphological structures of EC-N-GNS were analyzed by field emission scanning electron microscope and field emission transmission electron microscope. The electrochemical analysis of the cyclic voltammetry curves observed an electrochemical double-layer capacitor (EDLC) behavior with a potential window of −0.8 V to +0.5 V. The electrochemical galvanostatic charge—discharge study was obtained to be maximum specific capacitance (Csp)—67.69 F/g and 43.07 F/g at a current density of 1 A/g. We promising the facile single-step electrochemically exfoliated EC-N-GNS was obtained from a waste zinc-carbon primary battery to recycle the graphite electrodes. The superior electrochemical performance comparatively bulk graphite and EC-N-GNS for potential energy storage supercapacitor applications.

Polypyrrole-Assisted Ag Doping Strategy to Boost Co(OH)2 Nanosheets on Ni Foam as a Novel Electrode for High-Performance Hybrid Supercapacitors.

Battery-type electrode materials have attracted much attention as efficient and unique types of materials for hybrid battery supercapacitors due to their multiple redox states and excellent electrical conductivity. Designing composites with high chemical and electrochemical stabilities is beneficial for improving the energy storage capability of battery-type electrode materials. We report on an interfacial engineering strategy to improve the energy storage performance of a Co(OH)2-based battery-type material by constructing polypyrrole-assisted and Ag-doped (Ag-doped@Co(OH)2@polypyrrole) nanosheets (NSs) on a Ni foam using a hydrothermal process that provides richer electroactive sites, efficient charge transportation, and an excellent mechanical stability. Physical characterization results revealed that the subsequent decoration of Ag nanoparticles on Co(OH)2 nanoparticles offered an efficient electrical conductivity as well as a reduced interface adsorption energy of OH- in Co(OH)2 nanoparticles as compared to Co(OH)2@polypyrrole-assisted nanoparticles without Ag particles. The heterogeneous interface of the Ag-doped@Co(OH)2@polypyrrole composite exhibited a high specific capacity of 291.2 mAh g-1 at a current density of 2 A g-1, and showed a good cycling stability after 5000 cycles at 5 A g-1. The specific capacity of the doped electrode was enhanced approximately two-fold compared to that of the pure electrode. Thus, the fabricated Ag-doped@Co(OH)2@polypyrrole nanostructured electrodes can be a potential candidate for fabricating low-cost and high-performance energy storage supercapacitor devices.

Implementation and Validation for Multitasks of a Cost-Effective Scheme Based on ESS and Braking Resistors in PMSG Wind Turbine Systems

This study deals with fault ride-through (FRT) capability and output power fluctuation suppression of wind turbine systems (WTS) having PMSG (permanent-magnet synchronous generator) for mitigating grid frequency variation and voltage flicker in the distribution system. The coordinated control of a cost-effective scheme based on energy storage supercapacitors (ESSs) and braking resistors (BR) is introduced to perform the multiple tasks of the WTS. In this hybrid scheme, the ESSs are initially used to absorb the fluctuated power component with the constraints of their ratings during the grid faults and wind speed variation conditions prior to the activation of the BRs when the ESSs cannot fully consume the mismatched power between the PMSG and grid during severe grid faults. With the additional BRs, the capacity of the costly ESSs is remarkably reduced, while the performance of the fault ride-through capability and power smoothening for the WTS are still kept satisfactory and in compliance with the requirements of advanced grid codes. Detailed experimental implementation and its results for a down-scaled prototype in a laboratory are shown to verify the effectiveness of the introduced scheme along with the simulation results with the high-power rating WTS.