Energy Storage Components Research Articles

Optimal Configuration of Hybrid Energy Storage Capacity in a Microgrid Based on Variational Mode Decomposition

The capacity configuration of the energy storage system plays a crucial role in enhancing the reliability of the power supply, power quality, and renewable energy utilization in microgrids. Based on variational mode decomposition (VMD), a capacity optimization configuration model for a hybrid energy storage system (HESS) consisting of batteries and supercapacitors is established to achieve the optimal configuration of energy storage capacity in wind–solar complementary islanded microgrids. Firstly, based on the energy mapping relationship between the frequency domain and time domain, the decomposition mode number K of VMD is determined based on the principle of minimum total mode aliasing energy. Then, considering the smoothing fluctuation characteristics of different energy storage components, the dividing point N of high frequency and low frequency in the unbalanced power between the source and load in the microgrid is selected to allocate charging and discharging power instructions for the battery and supercapacitor. Finally, taking the annual comprehensive cost of the HESS as the objective function, a hybrid energy storage capacity optimization configuration model is established, and the dividing point N is used as the optimization variable to solve the model in order to obtain the optimal configuration results. The case study results show that the proposed method is more economical and feasible than the existing energy storage configuration methods.

Human-Powered Master Controllers for Reconfigurable Fluidic Soft Robots.

Fluidic soft robots have the advantages of inherent compliance and adaptability, but they are significantly restricted by complex control systems and bulky power devices, including fluidic valves, fluidic pumps, electrical motors, as well as batteries, which make it challenging to operate in narrow space, energy shortage, or electromagnetic sensitive situations. To overcome the shortcomings, we develop portable human-powered master controllers to provide an alternative solution for the master-slave control of the fluidic soft robots. Each controller can supply multiple fluidic pressures to the multiple chambers of the soft robots simultaneously. We use modular fluidic soft actuators to reconfigure soft robots with various functions as control objects. Experimental results show that flexible manipulation and bionic locomotion can be simply realized using the human-powered master controllers. The developed controllers which eliminate energy storage and electronic components can provide a promising candidate of soft robot control in surgical, industrial, and entertainment applications.

A novel method of prediction for capacity and remaining useful life of lithium-ion battery based on multi-time scale Weibull accelerated failure time regression

Lithium-ion batteries are essential energy storage components for electrical grid, and the health diagnosis determines the safety of the battery during usage and the rational classify of echelon utilization. In this article, a multi-timescale capacity and lifespan prediction method is proposed where capacity prediction and remaining useful life prediction are divided into the short-time scale and the long-time scale. For capacity prediction, the long short term memory neural network with five significant features is applied according to its accuracy performance in time series prediction. As for remaining useful life, the Weibull accelerated failure time regression is proposed to improve the prediction efficiency of a large amount of data. Finally, the predictive capability, robustness and effectiveness of proposed methods are verified using two datasets with different cycling test conditions within an error of 3.9 % in long-time scale and 2.7 % in short-time scale. The proposed method has great potential for targeted and accurate health state forecasting and long-term end of life prediction.

Review of Si-Based Thin Films and Materials for Thermoelectric Energy Harvesting and Their Integration into Electronic Devices for Energy Management Systems

Energy harvesters are autonomous systems capable of capturing, processing, storing, and utilizing small amounts of free energy from the surrounding environment. Such energy harvesters typically involve three fundamental stages: a micro-generator or energy transducer, a voltage booster or power converter, and an energy storage component. In the case of harvesting mechanical vibrations from the environment, piezoelectric materials have been used as a transducer. For instance, PZT (lead zirconate titanate) is a widely used piezoelectric ceramic due to its high electromechanical coupling factor. However, the integration of PZT into silicon poses certain limitations, not only in the harvesting stage but also in embedding a power management electronics circuit. On the other hand, in thermoelectric (TE) energy harvesting, a recent approach involves using abundant, eco-friendly, and low-cost materials that are compatible with CMOS technology, such as silicon-based compound nanostructures for TE thin film devices. Thus, this review aims to present the current advancements in the fabrication and integration of Si-based thin-film devices for TE energy harvesting applications. Moreover, this paper also highlights some recent developments in electronic architectures that aim to enhance the overall efficiency of the complete energy harvesting system.

Analysis of Optimal Load Management Using a Stand-Alone Hybrid AC/DC Microgrid System

Typically, diesel or other fossil fuel-based related applications meet electricity demand. Nonetheless, as the cost of fossil fuels rises, as do their harmful emissions, there is a sudden transition toward stand-alone hybrid renewable energy systems (HRESs). The proposed project proposes electrifying VIT University in Vellore, Tamil Nadu, India, using an off-grid HRES. The goal of enhancing hybrid energy system (HES) regulation, size, and component selection is to provide society with a cost-effective power supply. This article’s primary purpose is to show how to utilize HOMER Pro Software to reduce total net present cost, cost of energy, and CO2 emissions. After that, the findings were compared to four different HRES configurations. The efficient solution for transmitting power at the lowest energy cost is configuration 1 (solar + fuel cell + battery + wind + diesel generator) which is found to be the optimal solution for supplying energy with 0% unmet load at the least cost of energy, which is at 24.91 Rs/kWh. These data are used to calculate the optimal size of energy storage components based on long-term system behavior using HOMER and to forecast short-term generation and demand changes while maintaining system dependability and grid voltage. Using and incorporating model predictive control (MPC) for an interlinking converter (ILC), the proposed HRES design is validated for the study area in a novel way that sequentially applies HOMER and MATLAB simulations.

Construction of Alkaline Gel Polymer Electrolytes with a Double Cross-Linked Network for Flexible Zinc–Air Batteries

Flexible zinc–air batteries have broad potential as the next generation of energy storage component in wearable electronic devices. However, the mechanical performance and ionic conductivity of electrolytes are urgent issues that hinder the commercial application of flexible batteries. Herein, the alkaline gel polymer electrolyte (AGPE) with a double-network structure is developed, which consists of a covalently cross-linked polyacrylamide (PAM) by in situ polymerization and a physically cross-linked poly(vinyl alcohol) (PVA) by the freeze–thaw method. The freestanding PVA/N-PAM/KOH gel electrolyte demonstrates high ionic conductivity (309.9 mS cm–1) and excellent mechanical toughness (0.69 MJ m–3), benefiting from the synergistic effect of the double cross-linked system and hydrogen bonds. Meanwhile, the assembled ″sandwich″-type zinc–air battery presents excellent power density (40.43 mW cm–2), long-term cycle life (113 cycles), super-high-energy efficiency (70.2%), and stable discharge plateau. Impressively, the PVA/N-PAM/KOH-based batteries attached to the human body surface are reliably capable of powering light-emitting diodes.

Modulating the Proton‐Conducting Lanes in Spinel ZnMn2O4through Off‐Stoichiometry

AbstractThe intercalation of protons represents a notable component for energy storage in aqueous zinc‐ion batteries. However, the mechanism of proton transport in metal oxide cathodes, especially related to how the cation distribution modulates the proton‐conducting lanes, remains far from consensus due to the lack of suitable model materials. Here, taking spinel ZnMn2O4cathode as a prototype, it is disclosed that a deficiency of one half of lattice Zn ions can triple its specific capacity at high rates, which is predominantly contributed by proton storage. This promotion can be rationalized by the emergence of facile concerted proton transport in the Zn‐deficient sample, contrasting with the stoichiometric one, where proton intercalation undergoes a slow consecutive process. Furthermore, the restricted Zn motion in spinel phase causes high structural stability during cycling, preventing the recombination of external Zn ions with Zn vacant sites that readily accommodate protons. This work highlights the key role of controlled off‐stoichiometry in optimizing proton transport and storage for aqueous batteries.

An AI-Based Newly Developed Analytical Formulation for Discharging Behavior of Supercapacitors with the Integration of a Review of Supercapacitor Challenges and Advancement Using Quantum Dots

A supercapacitor is a type of electrical component that has larger capacitance, due to asymmetric behavior with better power density, and lower ESR (effective series resistance) than conventional energy-storage components. Supercapacitors can be used with battery technology to create an effective energy storage system due to their qualities and precise characterization. Studies have shown that the use of quantum dots as electrodes in supercapacitors can significantly increase their effectiveness. In this research article, we have used a Drude model based on free electrons (asymmetric nature) to describe the supercapacitor’s discharging characteristics. Commercially available Nippon DLA and Green-cap supercapacitors were used to verify the Drude model by discharging them through a constant current source using a simple current mirror circuit. The parameters of both the fractional-order models and our suggested method were estimated using the least-squares regression fitting approach. An intriguing finding from the Drude model is the current-dependent behavior of the leakage-parallel resistance in the constant current discharge process. Instead of using the traditional exponential rule, supercapacitors discharge according to a power law. This work reflects the strong symmetry of different aspects of designing a hybrid supercapacitor with high efficiency and reliability.

3D printing flexible supercapacitors based on crosslinked poly (acrylic acid‐co‐vinylimidazole)

AbstractSupercapacitors are an attractive technology for energy storage applications as they allow for fast charging of devices. The fabrication of flexible supercapacitors by additive manufacturing is a promising approach to produce energy storage components for applications where material flexibility and complex geometries are desirable. In this work, digital light projection (DLP) additive manufacturing is used to fabricate polymer electrolytes for flexible supercapacitors based on crosslinked poly(acrylic acid‐co‐vinylimidazole) (PAAVim). Ion gels are prepared through equilibration with 4M lithium chloride (LiCl) in ethylene glycol, deionized (DI) water and ethylene glycol/DI water mixtures. Flexibility and stretchability varied depending on the equilibration solvent with prepared PAAVim/LiCl polymer electrolytes exhibiting up to ˜700% elongation at break. Subsequent flexible supercapacitors fabricated by sandwiching the ion gel between carbon cloth electrodes delivered 60 F/g specific capacitance at the scan rate of 0.2 A/g with an energy density of 8.3 Wh/kg and a power density of 99.8 W/kg. Overall, this work demonstrates the fabrication of flexible capacitors through DLP additive manufacturing, where the resulting material physical and electrochemical properties can be varied through control over the resin chemistry.

Research on the performance characteristics of an oil-free scroll expander that is applied to a micro-scale compressed air energy storage system

The oil-free scroll expander, which is the power component of the micro-scale compressed air energy storage (CAES) system, exhibits a satisfactory application prospect. The expander's performance directly influences the efficiency of the expansion power generation system. To enhance the work efficiency of the power generation system, we built a thermodynamic model that facilitates the oil-free scroll expansion mechanism by considering heat transfer and leakage; furthermore, for the micro-scale CAES, we constructed an experiment bench that utilizes air as the working fluid. Based on computational fluid dynamics (CFD), we conducted a three-dimensional unsteady numerical simulation of the fluid flow that occurs in the working chamber of the scroll expander. We observed that the suction pressure loss that occurs during the suction process, which is initiated by the scroll expander, leads to inlet pressure drop, and we noted that the suction pressure directly influences the work efficiency of the power generation system. When the setup is subjected to rotational speeds of 1200–3200 r/min, the difference between the theoretical and measured values of volumetric flow decreases from 0.0226 to 0.000527 m3/min. The pressure, velocity, and temperature distribution of the fluid that exists in the working chamber of the expander are not uniform, and the mass exchange that occurs between adjacent working chambers considerably impacts the distribution of velocity and temperature. As gas flows from the back-pressure chamber to the outlet pipe, most of it flows through the non-deforming domain before flowing into the outlet pipe. The fluid flow in the deforming domain is highly complicated, and even secondary flow can occur.

Monolithic Bidirectional WBG Switches Rekindle Power Electronics Technology [Expert View

There are numerous mass volume power applications where it is necessary to control the flow of bidirectional power, including electric vehicles (vehicle to grid, vehicle to home, and vehicle to vehicle), distributed and grid-tie power systems using regenerated energy and/or energy storage components, and solid-state circuit breaker protection. Silicon carbide (SiC) and gallium nitride (GaN) based bidirectional power switches can enable these applications with their compelling advantages of high efficiency, high blocking voltage capability, and low system weight and volume. In particular, monolithic switches that allow for bidirectional symmetric conduction and voltage blocking with a chip area close to that of a similarly rated unidirectional switch are ideally suited to fuel a revolution in power electronics technology.

Mains Current Distortion Analysis and Suppression Method for Third-Harmonic Injection Two-Stage Matrix Converter

Compared with the direct matrix converter and the two-stage matrix converter (TSMC), the third-harmonic injection TSMC (3TSMC) has significant advantages in the input reactive power control range and the maximum linear voltage transfer ratio. However, for nonunity input power factor operations and high-mains-frequency applications, there are input current distortions in the 3TSMC. Further analysis reveals that the actual injection current cannot track the reference without error in the conventional harmonic current injection circuit, resulting in the current distortions. Therefore, an improved circuit is proposed, which is based on the asymmetric H-bridge and does not need extra energy storage components or current sensors. The injection current in the improved circuit can follow the reference without error by injection current modulation, which means that the input current distortions are suppressed significantly. All theoretical considerations are verified by experimental results taken on a 3-kVA prototype.

Electric Eel Biomimetics for Energy Storage and Conversion.

The electric eel is known as the most powerful creature to generate electricity with a discharge voltage up to 860V and peak current up to 1 A. These surprising properties are the results of billions of years of evolution on the electrical biological structure and bulk, and now have triggered great research interest in electric eel biomimetics for designing innovated configurations and components of energy storage and conversion devices. In this review, first, the bioelectrical behavior of electric eels is surveyed, followed by the physiological structure to reveal the discharge characteristics and principles of electric organs and electrocytes. Additionally, underlying electrochemical mechanisms and models for calculating the potential and current of electrocytes are presented. Central to this review is the recent progress of electric-eel-inspired innovations and applications for energy storage and conversion, particularly including novel power sources, triboelectric nanogenerators, and nanochannel ion-selective membranes for salinity gradient energy harvesting. Finally, insights on the challenges at the moment and the perspectives on the future research prospects are critically compiled. It is suggested that energy-related electric eel biomimetics will greatly boost the development of next-generation high performance, green, and functional electronics.

A Laser-Processed Carbon-Titanium Carbide Heterostructure Electrode for High-Frequency Micro-Supercapacitors.

Micro-supercapacitors (MSCs) are an important energy storage component for future miniaturized electronic systems, yet their key performance indexes such as high-frequency response, energy density, and cycle life still have a large room to be improved. Herein, a laser-processed carbon-titanium carbide heterostructure (LCTH) electrode is demonstrated, which can excellently address the above key challenges by employing a unique one-step laser-processing fabrication method. Different from the other reported electrode structures, this LCTH electrode shows a heterogeneous structure, featuring the carbon nanofoam layer which provides extremely short ion transport channels and abundant electrochemical active sites, and the underlying titanium carbide layer which can provide excellent electron conductivity and contribute to the pseudo-capacitance. The assembled symmetric supercapacitor can stably work at the voltage window of 3.5V at an ultra-high frequency of approximately 1121.3Hz, exhibiting an ultra-high areal specific energy density of 721 µFV2 cm-2 at 120Hz and a cycle life of 140 000 cycles with capacitance retention of 100.95%, which is superior to most reported MSCs. The as-fabricated MSC is compatible with the contemporary embedded electronic component fabrication processes, which shows significant advantages in large-scale fabrication and system integration, demonstrating a broad prospect for future system-in-package applications.

Stretchable all-in-one supercapacitor enabled by poly(ethylene glycol)-based hydrogel electrolyte with low-temperature tolerance

Hydrogel electrolytes are crucial components of stretchable energy storage devices due to their flexibility and excellent ion transport ability. However, most hydrogels lose their stretchability in subzero-temperature environments. Herein, a stretchable all-in-one supercapacitor that can work at low temperatures was developed by designing an anti-freezing polyacrylic acid (PAA) hydrogel incorporated with polyethylene glycol (PEG)/H2O solvent. PEG endowed the hydrogel with anti-freezing property while avoiding the instability of low-molecular organic solvents. The all-in-one supercapacitor was prepared through the in-situ polymerization and deposition of polyaniline on the faces of the anti-freezing hydrogel electrolyte. The obtained supercapacitor exhibited high capacitive performance, good stretchable capacity, and excellent cycling stability. Moreover, benefiting from the outstanding low-temperature tolerance capacity, the all-in-one supercapacitor can maintain an area specific capacitance of over 63.1% even at −25 °C. This work presents an innovative polymer-solvent system for developing an anti-freezing stretchable all-in-one configured supercapacitor for use as a portable energy storage device in wearable electronics.

Sodium alginate reinforced polyacrylamide/xanthan gum double network ionic hydrogels for stress sensing and self-powered wearable device applications

Strong and ductile sodium alginate (SA) reinforced polyacrylamide (PAM)/xanthan gum (XG) double network ionic hydrogels were constructed for stress sensing and self-powered wearable device applications. In the designed network of PXS-Mn+/LiCl (short for PAM/XG/SA-Mn+/LiCl, where Mn+ stands for Fe3+, Cu2+ or Zn2+), PAM acts as a flexible hydrophilic skeleton, and XG functions as a ductile second network. The macromolecule SA interacts with metal ion Mn+ to form a unique complex structure, significantly improving the mechanical strength of the hydrogel. The addition of inorganic salt LiCl endows the hydrogel with high electrical conductivity, and meanwhile reduces the freezing point and prevents water loss of the hydrogel. PXS-Mn+/LiCl exhibits excellent mechanical properties and ultra-high ductility (a fracture tensile strength up to 0.65 MPa and a fracture strain up to 1800%), and high stress-sensing performance (a high GF up to 4.56 and pressure sensitivity of 0.122). Moreover, a self-powered device with a dual-power-supply mode, i.e., PXS-Mn+/LiCl-based primary battery and TENG, and a capacitor as the energy storage component was constructed, which shows promising prospects for self-powered wearable electronics.

A Review of Remaining Useful Life Prediction for Energy Storage Components Based on Stochastic Filtering Methods

Lithium-ion batteries are a green and environmental energy storage component, which have become the first choice for energy storage due to their high energy density and good cycling performance. Lithium-ion batteries will experience an irreversible process during the charge and discharge cycles, which can cause continuous decay of battery capacity and eventually lead to battery failure. Accurate remaining useful life (RUL) prediction technology is important for the safe use and maintenance of energy storage components. This paper reviews the progress of domestic and international research on RUL prediction methods for energy storage components. Firstly, the failure mechanism of energy storage components is clarified, and then, RUL prediction method of the energy storage components represented by lithium-ion batteries are summarized. Next, the application of the data–model fusion-based method based on kalman filter and particle filter to RUL prediction of lithium-ion batteries are analyzed. The problems faced by RUL prediction of the energy storage components and the future research outlook are discussed.

Overview of Single-Stage High-Frequency Isolated AC–DC Converters and Modulation Strategies

The single-stage high-frequency (HF) isolated ac–dc converter has the advantages of high-power density, long life, and high efficiency. It has a broad application prospect in distributed power generation, ac microgrid, and energy storage system. In this article, its topologies are classified according to the energy storage components. The structure and operating principle of various topologies are introduced. Furthermore, the development of extended multiport single-stage HF isolated ac–dc converter is introduced. On this basis, the advantages and disadvantages, typical characteristics, cost, and power loss of various topologies are analyzed and summarized. Finally, the key issues that need to be solved are pointed out and the development trends are explored. This article aims to provide a reference for the subsequent research on single-stage HF isolated ac–dc converters and the advancement of their practicability.

Engineering Geometric Electrodes for Electric Field‐Enhanced High‐Performance Flexible In‐Plane Micro‐Supercapacitors

In plane micro‐supercapacitors that are miniaturized energy storage components have attracted significant attention due to their high power densities for various ubiquitous and sustainable device systems as well as their facile integration on various flexible/wearable platform. To implement the micro‐supercapacitors in various practical applications that can accompany solid state or gel electrolyte and flexible substrates, ions must be readily transported to electrodes for achieving high power densities. Herein, we show large enhancement in electrochemical properties of flexible, in‐plane micro‐supercapacitor using sharp‐edged interdigitated electrode design, which was simply fabricated through direct laser scribing method. The sharp‐edged electrodes allowed strong electric field to be induced at the corners of the electrode fingers which led to the greater accumulation of ions near the surface of electrode, significantly enhancing the energy storage performance of micro‐supercapacitors. The electric field‐enhanced in‐plane micro‐supercapacitor showed the volumetric energy density of 1.52 Wh L−1 and the excellent cyclability with capacitive retention of 95.4% after 20 000 cycles. We further showed various practicability of our sharp‐edged design in micro‐supercapacitors by showing circuit applicability, mechanical stability, and air stability. These results present an important pathway for designing electrodes in various energy storage devices.

Multi‐objective salp swarm algorithm‐based fractional order fuzzy precompensated PDPI controller for frequency regulation of hybrid power system

AbstractSignificant number of renewable sources when integrated with distributed generations and energy storage components form a sustainable power system called hybrid power system (HPS). But the stochastic nature of the sources and continuous variation of load cause serious issues in the power systems like frequency instability. Our work proposes a novel approach for load frequency control (LFC) of the proposed system. For the work, both frequency deviation and control signal are used to give the input signal to energy storage components. A new fuzzy‐based controller called fractional order fuzzy precompensated PDPI (FO‐FPPDPI) controller for LFC of the mentioned HPS is suggested in this paper. The controller is optimized by a nature inspired multi‐objective salp swarm algorithm (MSSA). The comparison of the proposed approach with the classical PID controller and Fuzzy PID (FPID) controller is carried out by taking several system operating conditions. Robustness of the FO‐FPPDPI controller is also validated for system parameter variations and the superiority of the proposed control strategy over PID and FPID controllers is validated for all the situations. Finally, the control strategy is realized in OPAL‐RT to measure its fidelity with the simulation results.