Search

Metal oxalate materials have been explored for electrochemical energy storage (EES) applications. Herein, Ni-incorporated gallium oxalate (Ni-Ga-C2O4) based binder-free electrode was fabricated through a facile process. The electrode gathers the benefit of Ni foam contributed as a conductive substrate and also acting as a Ni source with binder-free approach. The Ni-Ga-C2O4crystalline phase formation was confirmed through X-ray diffraction spectroscopy (XRD). The morphological properties and elemnetal quantification were studied via scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and transmission electron spectroscopy (TEM). Importantly, electrochemical energy storage investigation revealed the Ni-Ga-C2O4electrode exhibits battery behavior with capacity retention of 85.5 % and possessed the highest specific capacity of 319 C g−1at 1 A g−1. Overall, the additional contribution of Ni during the synthesis has boosted the physicochemical properties and electrochemical energy storage performance of the Ni-Ga-C2O4electrode.

The intrinsic meagre storage kinetics and electrical conductivity of transition metal oxides are posing significant obstacles to their exploration as electrode materials for supercapacitor applications. The hybridization of transition metal oxides with metal carbides (Mo2C and W2C) have shown as the promising approach for the electrode fabrication which offered enhancing electrical conductivity, specific surface area, and high porosity in the resulting nanocomposites. Hence, herein, we produced the NiO-Mo2C and NiO-W2C nanocomposite electrode materials by the hydrothermal process. The prepared NiO-Mo2C and NiO-W2C electrode materials exhibited improved specific capacitance, reaching 604 and 592 F g−1at 0.5 A g−1, respectively. Additionally, these materials demonstrated superior cycling stability, maintaining 96.5 % and 97.8 % of their initial capacitance even after 3000 cycles at a current density of 3 A g−1. Moreover, an asymmetric supercapacitor (ASCs) was fabricated with (NiO-Mo2C and NiO-W2C) as the positive and activated carbon (AC) as the negative electrode which exhibited enriched energy density of 37 and 34 Wh kg−1at a power density of 2.4 kW kg−1compared with pristine structures. Importantly, the illumination of light-emitting diodes (LEDs) by couple of connected ASCs authorized the prepared NiO-Mo2C and NiO-W2C materials' significant potential for practical applications.

Transition metal sulfides (TMSs) have been widely employed in energy storage applications due to their high theoretical capacity, improved electrical conductivity, and superior mechanical durability compared to analogous metal oxides. However, the use of TMSs in supercapacitors (SCs) presents several challenges, including limited potential ranges, reduced efficiency at high discharge rates, and concerns regarding long-term durability, issues not present when utilizing porous carbon materials. Several methods, such as component regulation, chemical structure adjustment, interface optimization, and TMSs composites engineering, offer potential avenues for enhancing SCs performance. Metal-organic frameworks (MOFs) are considered intriguing candidates for creating diverse TMS nanostructures due to their large surface area, substantial porosity, adjustable functional groups, and versatile chemical composition. Leveraging MOFs enables the customization of various TMS nanostructures, ranging from simple zero-dimensional (0D) structures to complex three-dimensional (3D) structures. These innovative nanostructures significantly improve the structural strength, increase active site exposure, and facilitate mass/electron transport. This offers several opportunities for enhancing the electrochemical properties of TMSs, including their capacity and stability. This review addresses the latest advancements in the rational design of MOFs-derived TMSs, varying in dimensionalities from 0D to 3D nanostructures for SC applications. Furthermore, it discusses potential challenges and prospects regarding the implementation of MOFs-derived TMSs in sustainable electrochemical energy storage, laying the groundwork for the research and innovation of advanced electrode materials with different dimensions.

Plug-in hybrid electric vehicles can be replaced by wireless charger-based electric vehicles because wireless power transfer is easier, safer, and more suitable for usage, especially in moist environmental conditions. In this paper, the wireless charger-based electric vehicle comprises two subsystems: an inductor-capacitor-capacitor series compensation network-based wireless charging system and a hybrid energy storage unit. The hybrid energy storage unit comprises a regenerative fuel cell that combines an electrolyzer with a fuel cell, a battery, and a supercapacitor. The primary function of the electrolyzer is to generate hydrogen to be utilized by the fuel cell. The wind-up effect manifests when integral error accumulates leading to overshoots and oscillations. The conventional super twisting-based sliding mode controller (ST-SMC) exhibits a wind-up phenomenon due to integral error accumulation and it can only cater to disturbances with known bounds. To address this issue, a barrier-condition-based super twisting sliding mode controller has been proposed to reduce the wind-up phenomenon when the integral error accumulates and cater to the disturbances with unknown bounds. Furthermore, an energy management system has been proposed to maintain a power balance between the state of charge of the supercapacitor and the battery as inputs. Lyapunov stability analysis has been used to ensure the asymptotic stability of the system. Controller gains have been tuned using the grey wolf optimization technique. Other controllers like ST-SMC and sliding mode control have also been proposed for performance comparison. Finally, the overall performance of the proposed controller has been validated using MATLAB/Simulink as well as through a Delfino-based real-time hardware-in-the-loop (HIL) setup.

MXenes have attracted considerable research interest in the field of energy storage due to their unique structure and favourable surface functional group properties. Recent efforts are focused extensively on synthesizing MXene composites for fabricating ideal electrode materials for energy storage applications. To fully exploit the characteristic features of MXene nanosheets and to ensure superb mechanical properties, cellulose is frequently used in combination with MXene to design high-potential functional nanocomposites. Cellulose serves as a promising reinforcing filler and flexible substrate due to its excellent mechanical strength. Its one-dimensional filamentous structure minimizes insulating contacts between 2D materials, enhancing both supercapacitive and mechanical properties. Furthermore, the 3D printing of micro-supercapacitors (MSCs) using MXene/cellulose inks yields desired printed interdigitated patterns with higher geometric accuracy, resulting in superior mechanical strength and capacitive performance. In this article, we present a comprehensive and timely review of recent research efforts and their outcomes related to the fabrication of flexible supercapacitors (SCs) based on MXene/cellulose composites. The scope extends to the fabrication of MXene/cellulose MSCs and electrodes that are wearable or free-standing. The initial sections of the article delve into the current synthesis methodologies for MAX phase and MXene, highlighting structural variations resulting from different synthesis procedures. Subsequently, we discuss the synthesis procedures for MXene/cellulose composites, the fabrication of MXene/cellulose based SCs, and their performance. Towards the end, we address existing research gaps and provide insights into future perspectives regarding MXene/cellulose SCs, drawing from the latest research findings. This review underscores the pivotal role played by MXene/cellulose composites in advancing the field of energy storage.

In this study, we present a novel electrode comprised of Ti3C2TxMXene, which has been integrated with NiMoO4nanoflakes (referred to as Ti3C2Tx/NiMoO4-P), achieved through a straightforward mixing of their respective solutions. The NiMoO4particles inhibited the restacking of MXene sheets, thus leading to the effective utilization of active surface area by facilitating the intercalation of electrolyte ions. The binder-free Ti3C2Tx/NiMoO4-P electrode displayed a superior specific capacitance of 550 F g−1(440 C g−1) as compared to an electrode developed through a hydrothermal and calcination treatment, referred to as Ti3C2Tx/NiMoO4-H which displayed a specific capacitance of 472 F g−1(377 C g−1) at 2 mV s−1in 0.5 M H2SO4solution. Moreover, the Ti3C2Tx/NiMoO4-P electrode exhibited excellent cyclic stability with 81 % capacitance retention after 5000 cycles at 50 mV s−1. A symmetric supercapacitor consisting of Ti3C2Tx/NiMoO4-P electrode delivered a maximum capacitance of 71.5 F g−1at 0.5 A g−1with a high energy density (9.3 Wh kg−1at a specific power density of 2.5 kW kg−1). The heterostructure of Ti3C2Tx/NiMoO4-P provided significant insight into enhancing the energy storage performance by controlling the interlayer spacing to develop flexible energy storage devices.

Energy storage materials have gained significant attention over the past two decades. MXenes, an excellent two-dimensional (2D) material is the most recent and active member of the 2D family which is studied extensively. Among various MXenes, Ti-MXene has emerged as a widely utilized material. However, other transition metal alternatives also potentially serve the function of 2D MXene for various applications. Hence, non-Ti-based MXenes, particularly niobium (Nb) based MXenes (Nb2CTxand Nb4C3Tx) have recently gained interest due to their unique properties. This article reviews the structures, properties, various synthesis routes, and applications of Nb-based MXenes, specifically focusing on their utilization in supercapacitors. The paper discusses the recent findings and concludes by addressing the future prospects of Nb-based MXenes for supercapacitor applications.

The paper proposes a control strategy for a plug-in hybrid electric vehicles (PHEVs) system that integrates a photovoltaic (PV) based renewable energy system (RES) and battery and supercapacitor (SC) based energy storage systems (ESS). In the proposed system, a current fed converter is implemented for the photovoltaic and supercapacitor which is a power electronic converter that operates by controlling the current flow in the circuit. The benefit of these converters is that core saturation and shot through cannot lead to device failure or half cycle symmetry. This is a feature of silicon controlled rectifier (SCR) based converters and is a key factor in the increased durability of these converters. A power bi-directional converter is employed for the battery in the EV system. This converter enables the battery to both charge and discharge power as required by the system which facilitates the energy flow between the battery and the rest of the system, allowing efficient energy management and utilization within the plug-in hybrid electric vehicles. Additionally, to efficiently utilize the photovoltaic system, an artificial neural network (ANN) is employed to determine the maximum power points (MPPs). A robust nonlinear higher order super twisting sliding mode controller (STSMC) and integral terminal sliding mode controller (ITSMC) have been designed for PHEVs to reduced chattering phenomena. Tables V to X provides a detailed comparison of error performance metrics and transient response characteristics for the state of charge of a renewable energy system and energy storage systems under the control of the optimized STSMC and ITSMC. The global asymptotic stability of the control approach is verified using Lyapunov stability analysis. Finally, MATLAB/Simulink and a hardware-in-the-loop (HIL) experiments are done to show the behavior of proposed system (Pirouzi et al., 2022).

The enormous addition of CO2is alarming for sustainability and efficient conversion of CO2into valuable products is emerging technique for sustainable future. Photocatalytic reduction of CO2by using solar energy is emergent not only for environmental concerns but also production of suitable chemicals and fuels. Metal-organic frameworks have been considered in forefront in photocatalysis due to porous and adjustable structure. By using the post-modifications in the metallic nodes and linkers, the structure of MOFs can be tuned, however, the proper functionalization of MOFs cannot be achieved without the knowledge of photocatalytic mechanism. Herein, we have summarized the recent advancements in pristine MOF-based photocatalysts focusing on the mechanistic studies for CO2reduction reaction. This article has established the structure-performance relationship in MOFs to lead the novel strategies for efficient photocatalysts. Finally, the concluding remarks also provides some future directions in the field.

A facile wet-chemical assisted synthesis route is adapted to prepare a novel SnO2/SnSe nanocomposite for the time to construct an aqueous asymmetric hybrid supercapacitor (AAHSC). The detailed characterization reveals the appropriate formation of micro flower-like SnO2-SnSe nanocomposite-covered with SnSe network to provide a conductive support and facilitate charge transport during the electrochemical processs. Compared with pure SnO2micro flowers and SnSe electrodes, the SnO2-SnSe nanocomposite electrode delivers a brilliant charge storage performance. A rapid charge transport pathways was accomplished due to the lowest charge transfer resistance, resulting in a high capacitance and improved charge storage properties in an aqueous alkaline electrolyte solution with incredible reversibility and rate capability. Inspired by the excellent charge storage and capacitive properties, a two-cell mode-based AAHSC was built with SnO2-SnSe nanocomposite (cathode) and activated carbon (AC) as an anode (symbolized as SnO2-SnSe||AC/KOH) displayed the highest energy of 33.4 Wh/kg at a maximum power of 4003.7 W/kg, operating in a voltage of 1.6 V with excellent cycling stability of 89.5 %.

In today’s ever-evolving power generation landscape, a transformative shift is unfolding, propelled by the rise of renewable energy microgrids, revolutionizing conventional electricity generation. The novel idea presented in this work addresses the intricate control and optimization challenges inherent in hybrid AC/DC microgrids that integrate various distributed generators, energy storage technologies, loads, converters, and inverters. To overcome these complexities, we introduce a novel approach centered on a condition-based super-twisting sliding mode control (CBSTSMC). This control strategy offers several advantages, including chatter-free operation and enhanced robustness. Notably, the CBSTSMC addresses the wind-up phenomenon during control signal saturation, a common issue in microgrid control, thereby contributing to improved system stability. Furthermore, we have also focused on various aspects of the microgrid including the use of artificial neural networks for maximum power point tracking of wind and PV systems, an energy management system, and Grey Wolf optimization for gain tuning of controllers. The system’s stability is rigorously validated through Lyapunov analysis. To validate real-time control effectiveness, the proposed approach undergoes experimental verification using hardware-in-loop implementation, employing a C2000 Delfino microcontroller, in tandem with simulation in MATLAB/Simulink. The CBSTSMC approach is also compared with sliding mode control and super twisting sliding mode control.

NiCo2O4(NCO) is an auspicious pseudocapacitor material for high energy density zinc-ion hybrid supercapacitors (ZHSCs), but its low intrinsic conductivity and significant volume expansion seriously hinder its electrochemical performance. Here, we develop a nitrogen (N) doped and oxygen-vacancy-rich (Ov) NiCo oxide nanolines grown in-situ on the carbon cloth (CC) named N-Ov-NCO@CC. The morphology and structure of N-Ov-NCO@CC were characterized by XRD, XPS, EPR, SEM and TEM. It can be clearly observed that N-Ov-NCO@CC nanowires are composed of many tiny nanoparticles, and this unique structure provides abundant gaps at the microscopic scale, providing ample sites for the attachment of electrolyte ions. Due to N-functionalization, synergistic effects of doping, defect and surface engineering are realized. As a result, N-Ov-NCO@CC exhibits significantly enhanced electrochemical performance. The N-Ov-NCO@CC single electrode exhibits a high capacitance of 993.0 F/g (496.5C/g) at 1 A/g and excellent cycle stability with a capacitance retention rate of 98 % after 5000 cycles. In addition, the assembled N-Ov-CCO@CC//Zn-ZHSC operates stably in the voltage range of 1.2–2.0 V. A high specific capacitance of 484.4 F/g is available at current densities of 1 A/g. In addition, it still has a high cycle life with a capacitance retention rate of 97.1 % after 10,000 cycles and a high specific energy/power (50.3 Wh/kg at 300.2 W/kg). Density function theory (DFT) verification shows that N-Ov-NCO has higher conductivity than Ov-NCO and pristine NCO, which is conducive to improving electrochemical performance. This work provides a new idea for developing stable electrode materials for new ZHSCs.

Supercapacitors (SCs) are emerging energy storage devices for commercialized purposes due to their high–power density, extended life cycle, environmental friendliness, and cost–effectiveness. However, low energy density is a significant shortcoming for their implications in practical applications. The performance of the SCs is based on rate capability, specific capacitance, power, and energy densities. To deal with the problem of low energy density, novel electrode materials with high stability and capacitance are urgently required. The electrical and electrochemical properties of electrode materials heavily influence their overall performance. The density functional theory (DFT) has significantly contributed to studying electrical properties, which provides a strong tool for screening the electrode materials of SCs. This review aims to provide recent advances in different theoretical techniques to improve and screen out the best electrode materials for SCs. We summarized theoretical calculations of various electrode material families, including metal oxides (MOs), metal sulfide/selenides/phosphides, metal carbides and nitrides (MXenes), transition metal dichalcogenides (TMDs), and, metal–organic frameworks (MOFs), etc., and evaluated their performance and outlined their DFT calculations. We also highlight the literature based on DFT calculations of the materials with possible approaches to tune the electrical properties to achieve high–performance electrode materials for SCs.

The growing energy demand and rising fossil fuel expenses in isolated and remote regions have increased interest in renewable energy sources (RESs). However, RESs such as photovoltaics (PVs) and wind turbines (WTs) are intermittent and fluctuating; hence reliability is a major concern. The hybridization of RESs with energy storage systems can effectively address their fluctuations and intermittency and enhance overall efficiency; however, the corresponding system cost is a primary concern. Thus, determining the optimal sizing of a hybrid system is the major challenge. Previous studies have suggested metaheuristic algorithms that rely on specific parameters to find an optimal solution. To address this issue, a hybrid algorithm, namely JGWO, which combines JAYA and grey wolf optimizer (GWO), has been proposed. The aim is to solve the unit sizing problem of a hybrid system (PV-WT-battery) that can meet consumers’ demands at the lowest total annual cost (TAC) while considering the maximum allowable probability of power supply loss (LPSPmax) to ensure system reliability. The JGWO is compared to JAYA, GWO, genetic optimization algorithm (GOA), and teaching-learning based optimization (TLBO) in reliability and TAC. Findings reveal that JGWO outperforms existing algorithms at LPSPmax values of 0%, 1%, 3%, 2%, and 5%, yielding TAC of 66542, 61102, 50247, 43046, and 34464 USD, respectively, for a hybrid system (PV-WT-battery). The results also show that the proposed hybrid PV-WT-battery system is more cost-efficient than PV-battery and WT-battery systems, regardless of the LPSPmax value.

This study presents a simple hydrothermal synthesis method for preparing CoSe2, ZnS, and their nanohybrid combinations (ZnS-70 % CoSe2and ZnS-50 % CoSe2, referred to as ZC-1 and ZC-2) for the first time. These materials are intended for application in a supercapacitor (SC) and are synthesized through an ex-situ wet-chemical approach. The research thoroughly examines the electrochemical properties of as-prepared electrodes and how they relate to their structure and morphology to understand their charge storage mechanism better. The detailed characterization reveals that a one-step hydrothermal reaction obtains the cubic crystal structure of the ZnS with microsphere morphology, and the CoSe2presents a snow crystals-like morphology with a highly smooth and transparent surface appearance. The systematic electrochemical examination declares the typical pseudocapacitive charge storage response owing to fast Faradaic redox reactions with good reversibility and rate capability. Notably, a high capacitance of CoSe2-ZnS nanohybrid (denoted as ZC-2) is realized by the synergistic effect between ZnS and CoSe2supported by the impedance, cyclic voltammetry, and charge/discharge studies. High specific energy with a power of 46.71 Wh/kg (899.21 W/kg) and 9 Wh/kg (5400 W/kg) is realized by adding an optimal voltage and capacitance simultaneously by fabricating a hybrid asymmetric HASCs (ZC-2||AC HASC) in aqueous solution. This study believes that metal sulfide and selenide-based nanohybrids can be effective candidates for competing in the growing electrochemical energy storage demand.

Technology and its advancement has led to an increase in demand for electrical energy storage devices (ESDs) that find wide range of applications, from powering small electronic gadgets such as smartphones and laptops, to grid-scale energy storage applications. It is also pertinent to note that batteries are imperative for enabling electric vehicles, which can help reduce dependency on fossil fuels and decrease carbon emissions. Lithium-ion batteries (LiBs) are widely deployed energy-storing devices that dominate the battery market featuring so far the highest energy density among other conventional systems along with long cycle life and power density. Despite this, LiBs are not able to provide sufficient energy density having reached their practical energy density limit, which is an obstacle for their use in Electric Vehicles (EVs) for long driving ranges or other high end electronic devices. Their limited reserves are also jeopardizing its industry. Hence, solutions need to be explored to enhance its energy density by investigating high performance materials, all while utilizing the existing infrastructure for these batteries. As a result, the world is looking for high performance next-generation batteries. The Lithium-Sulfur Battery (LiSB) is one of the alternatives receiving attention as they offer a solution for next-generation energy storage systems because of their high specific capacity (1675 mAh/g), high energy density (2600 Wh/kg) and abundance of sulfur in nature. These qualities make LiSBs extremely promising as the upcoming high-energy storing technology. Therefore, LiSBs are emerging as the next-generation batteries as they are able to provide high capacity at a lower cost. The sulfur that is used as the cathode in LiSBs is less expensive than the cobalt used in LiBs. Nevertheless, several obstacles must be addressed to render them a feasible choice for real-world implementations. The sulfur cathode encounters numerous obstacles such as high-volume increase, lower conductivity, and shuttling effect resulting from the dissolution and movement of polysulfides (PS). Expanding on this line, the purpose of this review is to provide a general overview of the development and advancement of LiSBs regarding sulfur-based composite cathodes, separator modifications, binder, and electrolyte improvement, and lithium metal protection along with a rational behind its research and technology adaptation in future.

Among different energy storage devices, supercapacitors have garnered the attention due to their higher charge storage capacity, superior charging-discharging performance, higher power density, and long cycle life. Subsequently, introducing low-cost and highly-efficient supercapacitors is a hot topic in the industrial and scientific realms. Metal oxides are considered as the most suitable electrode materials due to their intrinsic properties, economic attractiveness, environmental friendliness, and abundant availability. However, there is still a salient need to have e comprehensive study of the significance of metal oxide nanomaterials for supercapacitors in relation to their sustainable synthesis approaches. Thus, this review delineated the different sustainable synthesis approaches for metal oxide nanomaterials following their morphological, compositional, and supercapacitive properties. Initially, the review covers designs or configurations of supercapacitors followed by the types of supercapacitors based on electrode materials. Further, metal oxides-based pseudocapacitive-/battery-type electrodes have been articulated comprehensively. Moreover, this review aims to provide sustainable fabrication of metal oxide nanomaterial-based supercapacitors with a superior interpretation of the design and functioning of the device that could serve as guidelines for new synthesis and fabrication approaches to develop sustainable supercapacitors for practical applications.

In recent progress of electrode development, transition metal selenides have drawn great attention in supercapacitors. Their admirable properties have been exhibited through superior electrochemical performance, lower cost, and environmental friendliness. For the first time, we successfully demonstrate the structural orientation of ternary Mg-Ni-Co selenide (MNCSe) by fine-tuning of solvothermal reaction temperature. Self-alignment MNCSe nanoflakes facilitates the electrochemical performance by providing porous channels and large specific area. The self-aligned star-like MNCSe-180 nanoflakes can deliver a high specific capacity of 299.16 mAh g−1(1 A g−1) in an aqueous KOH electrolyte. Moreover, a hybrid supercapacitor device provides a high energy density of 46.56 Wh kg−1and a maximum power density of 5.9 kW kg−1. Hence, the presented electrode design holds great promise in material synthesis and this work also provides a deep understanding of the charge-storage process of novel materials capable of capacitive properties for next-generation energy storage devices.

This paper proposes a hybrid energy storage system (HESS) and smart charging mechanism for plug-in hybrid electric vehicles (PHEVs) with the aim of reducing greenhouse gas emissions and fossil fuel consumption. The HESS includes a battery as the main energy source and an ultra-capacitor (UC) as an auxiliary source. Both the power sources are connected to the DC bus through power conditioning circuitry. To regulate the system’s output variable, a barrier function-based adaptive sliding mode controller is proposed, which will achieve finite-time convergence and robustness against disturbances and uncertainties without requiring prior knowledge of the upper bounds of the system. The controller aims to reduce chattering and ensure various control objectives, such as tight regulation of output voltage, perfect tracking of reference currents for the UC and battery, and power factor correction in the grid-to-vehicle (G2V) mode. Simulation results using MATLAB/Simulink show that the proposed controller outperformed sliding mode control (SMC) and finite-time synergetic control (FTSC). The proposed strategy has been validated through real-time hardware-in-the-loop (HIL) experiments using C2000 Delfino Microcontroller F28379D Launchpad.

Plugin hybrid electric vehicles in contrast to traditional hybrid electric vehicles (HEV) are getting enormous attention in the modern electric transportation market as they address the environmental issues, fuel economy crisis, and CO2emission. Fuel cell-based PHEV with smart charging mechanism is an important application of the clean energy generation and storage system. There are two main subsystems in a PHEV: A hybrid energy storage system (HESS) and an integrated charging unit (ICU). In this study, an effective control strategy for the charger and HESS comprising three power sources: Fuel cell (FC), battery, and a superconducting magnetic energy storage (SMES) connected to the DC bus is presented. Due to the non-linearity of power conditioning circuits in ICU and HESS, designing a robust nonlinear controller is still a challenge. A barrier function-based adaptive terminal sliding mode controller is proposed to ensure the finite-time convergence of the output variable. It also maintains it in a predefined neighborhood of zero without overestimating the control gain and hence exhibits better dynamic performance in the presence of external disturbances of unknown upper bound. The asymptotic stability of the system has been ensured by using the Lyapunov stability criterion. Finally, the energy management algorithm in HESS using the state of charge of the battery and SMES as the decisive factor is incorporated to maintain the stability of the system under varying load conditions. The performance of the proposed controller has been compared with conventional nonlinear control techniques like adaptive terminal sliding mode control (ATSMC) and supertwisting sliding mode control (STSMC) by using MATLAB/Simulink. The performance of the system is further validated by using a C2000 Delfino F28379D MCU dual-core microcontroller with a hardware-in-the-loop (HIL) setup.

Conventional power generation resources are depleting rapidly and world power sector has been moving towards renewable energy sources (RESs). In this paper nonlinear control for renewable energy and hybrid energy storage system (HESS) based DC microgrid (DCMG) has been presented. PV and wind energy being the renewable sources whereas fuel cell, battery and ultracapacitor constitute the HESS. The global mathematical model of the said system has been presented. Datasets of varying solar irradiance and temperature have been trained by Artificial Neural Network for the reference voltage generation of PV. Integral terminal sliding mode controller (ITSMC) has been proposed for the output DC bus voltage regulation. Lyapunov stability criterion has ensured the overall stability of the system. A comparison of ITSMC with SMC and Lyapunov redesign controller has also been presented. Grid connected battery electric vehicle charger with grid to vehicle (G2V) and vehicle to grid modes (V2G) has been presented being an application of DCMG. The proposed system has been validated by using MATLAB/Simulink (2020b). Moreover, the hardware in loop setup has been used to observe the real time applicability of the proposed controller.

Zn-ion hybrid supercapacitors (ZHSCs) with high power and energy density have great potential in energy storage applications such as hybrid vehicles and renewable energy storage. However, the large radius of hydrated Zn2+-ions hampers their efficient storage in micropores with limited pore sizes, resulting in limited weight ratio capacitance and poor rate capability of ZHSCs. In this study, we developed the novel N-doped and oxygen vacancy-rich CCO nanowires (N-Ov-CCO@CC) architecture with the help of Chemical Vapor Deposition (CVD). Due to the guiding synergy of N-doping, defects, and surface engineering, N-Ov-CCO@CC exhibits significantly enhanced electrochemical performance. The N-Ov-CCO@CC single electrode exhibits excellent charge storage properties, including a high capacitance of 1480.7 F/g at 1 A/g, excellent rate-capability (88.4 % at 20 A/g), and excellent cycle stability of up to 90.1 % for 5000 cycles. The charge storage mechanism was analyzed by ex-situ XRD and XPS, and it reveals that the pseudocapacitive charge storage characteristics are dominant. Operating in the potential range of 1.2–2.0 V, the N-Ov-CCO@CC//Zn-ZHSC provides a high capacitance of 308.2 F/g at 1 A/g, excellent rate capability (86.9 % at 10 A/g), long lifetime (97 % after 10,000 cycles), and high specific energy/power (134.32 Wh/kg at 9507.6 W/kg). Density function theory (DFT) validations show that the N-Ov-CCO system possesses higher conductivities than Ov-CCO and pristine CCO. This work provides an effective strategy for constructing multifunctional electrochemical energy materials for ZHSCs.

Due to their simple structure and tremendous energy efficiency, direct current (DC) microgrids are becoming popular. The recent transition in power generation and consumption is based on the integration of renewable energy sources using DC microgrids. To facilitate this integration, a multi-source DC microgrid structure with five different sources including hybrid photoelectrochemical and photovoltaic (HPEV) cell, fuel cell, supercapacitor, battery and wind is presented in this paper. All the sources are linked to the DC bus via DC-DC power converters. Maximum power points for HPEV and wind have been obtained using artificial neural network. Nonlinear sliding mode controller, integral sliding mode controller, double integral sliding mode controller and super-twisting sliding mode controller have been presented for the output voltage regulation of the power sources. Global asymptotic stability of the framework has been verified using Lyapunov stability analysis. For load-generation balance, energy management system based on fuzzy logic has been devised. The proposed nonlinear controllers have been simulated and compared using MATLAB/Simulink®. Real-time hardware in the loop (HIL) experiment has been performed on the C2000 Delfino Microcontroller F28379D Launchpad for the validation of the proposed nonlinear controllers framework and compared with simulation results to validate the performance of the designed system.

Wireless charging technology for electric vehicles (EVs) is gaining popularity as a result of advancements in battery technology and government incentives. It offers convenience, efficiency, and safety, and is much quicker than traditional plug-in charging. However, optimal power transfer in a wireless power transfer (WPT) system remains a challenge. To design an effective control system for a hybrid energy storage system (HESS), it is important to have an accurate and reliable model of the system. But still, no model can fully represent the nonlinearity of the system. So model-free controllers are designed to operate without an explicit model, using feedback from sensors to adjust the control inputs. This article presents an LCC series-series network-based WPT-HESS model, supported by literature. The HESS system consists of a supercapacitor (SC) and a battery connected to the WPT system through a bidirectional DC-DC buck-boost converter. Three types of machine learning-based model-free controllers, i.e., an artificial neural network controller, a fuzzy logic controller, and a reinforcement learning-based deep Q-network controller, are designed for the HESS DC-DC converters aimed at tracking optimal power. During charging, the supercapacitor is given priority due to its faster charging time, and current references are generated based on the state-of-charge (SoC) of the supercapacitor and battery. The proposed controllers for WPT-HESS are simulated in MATLAB/Simulink and hardware validation is carried out by doing a hardware-in-loop experiment with the C2000 Delfino™ and the MCU F28379D LaunchPad, which has a TMS320F28379D dual-core CPU and runs at 200 MHz.

Plug-in electric vehicle (PEV) is the long-term eco-friendly solution to conventional fossil fuel based vehicles. In this study, a novel nonlinear barrier conditioned super-twisting sliding mode controller (BC ST-SMC) is proposed for the control of the PEV. The conventional super-twisting sliding mode control (ST-SMC) can only cater for the disturbances with known bounds and exhibits wind-up effects in the presence of saturated inputs which deteriorates the closed-loop performance of the system. The proposed BC-ST SMC solves these problems by providing anti-windup and un-bounded disturbance rejection. Lyapunov stability criterion is used to prove the asymptotic stability of the system. The PEV comprises of two subsystems namely: bidirectional charging unit (BCU) and hybrid energy storage system (HESS). The BCU comprises of a totem pole power converter between the PEV and grid which operates in two modes of grid to vehicle (G2V) and vehicle to grid (V2G). The components of the HESS are the battery and regenerative fuel-cell (RFC) (i.e. fuel-cell (FC) with an electrolyzer). The electrolyzer generates hydrogen which is required for the FC. Fuzzy-logic based energy management system (EMS) is adopted to maintain the power balance using state of charge (SoC) of the battery and electrolyzer as inputs. Furthermore, the controller gains are tuned using multi-objective genetic algorithm (MOGA) and multi-objective grey wolf optimizer (MOGWO) using integral absolute derivative of control input (IADU) with integral square of the error (ISE) as a fitness function. The simulations are performed on MATLAB® Simulink (2022b) which proves the superior performance of BC ST-SMC over conventional nonlinear controllers in the presence of saturated inputs. Finally, hardware-in-loop (HIL) based experimental results verify the real-time control of the proposed PEV.

The widespread adoption of electric vehicle (EV) ecosystem is tantamount to providing a reliable means of charging of vehicle battery through a critical component i.e., an EV charger. This paper presents a bidirectional EV charger system comprising of AC to DC converter, dual active bridge (DAB) and equivalent battery model has been proposed. Furthermore, a novel barrier conditioned double super-twisting sliding mode controller (BC DST-SMC) is presented in this study. The proposed approach is applied to cater the system disturbances and improve the controller’s performance in terms of robustness and disturbance rejection. Furthermore, a methodical optimization approach is taken to tune the proposed controller gains instead of error-and-trial approach. The gains of the proposed controller have been tuned using meta-heuristic algorithm “genetic algorithm” (GA), “improved-grey wolf optimizer” (I-GWO) and “neural network algorithm” (NNA) with integral square error (ISE) as an objective function. The optimization results show that NNA generates the most optimized gain values. The proposed model and controller are simulated using ODE45 solver settings in Simulink, MATLAB® (2023a) where its comparison is done with the conventional super-twisting sliding mode controller (ST-SMC). The proposed framework has also been validated through hardware-in-loop (HIL) experimental setup using MicroLabBox DSP-based dSPACE-DS1202.

The adoption of electric vehicles as a potential solution to the increasing energy crisis and environmental concerns has been on the rise. The development of smart grid concepts has further amplified the role of electric vehicles through the incorporation of vehicle-to-everything (V2X) technology. V2X is a comprehensive term that encompasses the use of electric vehicle batteries to derive additional value during non-use times. Bi-directional charging is employed to generate revenue from the battery asset to provide benefits to the electric grid, reduce energy consumption of buildings and homes, or provide backup power to loads. This paper presents an overview of the current state-of-the-art V2X operation of electric vehicles. It commences by discussing V2X frameworks such as vehicle-to-grid (V2G), vehicle-to-home (V2H), vehicle-to-building (V2B), vehicle-to-vehicle (V2V), vehicle-to-load (V2L), and vehicle-for-grid (V4G). Additionally, the infrastructure of V2X is analyzed with respect to control modes, power flow, types of charging systems, charging/discharging strategies, and the role of aggregator and IoT in the V2X system. Various standards and operational strategies for V2X are also examined. Moreover, this paper explores the crucial role of power electronics in ensuring reliable V2X operations and cyber-physical systems. The increasing penetration of renewables and the role of V2X in utilizing these resources efficiently are also studied. The global representative V2X projects that have already been implemented or are in the current phase are discussed. Finally, the challenges and barriers to the implementation of V2X are detailed, and future perspectives and policy recommendations are provided to make full use of this technology for a sustainable future.

Two-dimensional materials, including graphene and its derivatives, MXenes, and transition metal dichalcogenides, have attracted significant research attention due to their unique physicochemical properties. Among the various applications of these materials, energy storage and conversion have gained particular importance in light of the ongoing energy crisis. In this review, a critical evaluation is presented, focusing on the fundamentals, recent developments, and future perspectives of two-dimensional materials as anodes in lithium-ion batteries. The emphasis of this evaluation lies specifically on the years between 2010 and 2023. The review will primarily delve into the design and manipulation of advanced interface architectures for anodes, the latest developments, and the composition structure-property relationship of transition metal dichalcogenides (TMDs), MXenes, molybdenum disulfide (MoS2), tungsten sulfide (WS2), and black phosphorous (BP). The main focus of the presented review revolves around modification techniques that hold great potential in energy storage applications and other energy-related fields. The exceptional characteristics of these materials, including efficient ion transport across layers and large surface areas facilitating enhanced ion adsorption and accelerated surface redox reactions, contribute to their promising performance. While we have accumulated about twenty years of experience in energy conversion applications, particularly in lithium-ion batteries, we found that a large number of articles have been published on electrodes and electrolytes. However, a critical discussion about the composition structure-property relationship, along with challenges and optimizing strategies for anodes, is still lacking. Therefore, this review aims to fill that gap. Additionally, an overview of recent research advances is provided, focusing on the application of 2D materials in advanced energy storage systems beyond conventional lithium-ion batteries. Key findings and strategies employed to address associated challenges are examined while considering the prospects of these materials in the field.

As a supercapacitor material, transition metal selenide (TMS) can be synthesised in a cost-effective and simple manner. However, it suffers from low-rate capacities and poor cyclic stability due to their easy aggregation and structural instability during charge and discharge cycles. Herein, we report the synthesis of aluminum selenide (Al2Se3) nanorods over reduced graphene oxide (rGO) nanosheets as a novel material using the solvothermal method. The successful formation of Al2Se3/rGO nanocomposite was confirmed via XRD (X-ray diffraction), SEM (scanning electron microscopy), and XPS (X-ray photoelectric spectroscopy) and was also investigated for its optical characteristics and electrochemical performance. The optimised Al2Se3/rGO sample with 5 wt% and 10 wt% rGO exhibited high specific capacitances of 701.83 Fg−1and 1138.1 Fg−1, respectively. Moreover, Al2Se3/10%rGO nanocomposite as a positive electrode achieves energy densities of 39.57 Wh/kg and power densities of 0.006 kW/kg at current densities 2.5 A/g along with stability up to 2000 cycles, suggesting it to be a significant technological candidate in the future. This work highlights an effective and feasible approach to engineer or construct TMS/rGO nanocomposites for charge storage applications.

The battery electric vehicle (BEV) charger provides an effective two-way interconnection between the grid and the vehicle in both grid to vehicle (G2V) and vehicle to grid (V2G) configurations. However, the control of power flow in either of the configurations is a challenging task. In this study, a supertwisting sliding mode-based controller (ST-SMC) is designed for the control of the bi-directional power converter in a BEV charger for tracking the desired current and output voltage of the charger in both G2V and V2G operations. The proposed controller reduces the chattering effect, which is a major drawback in power converters. The robust integral backstepping controller (IBS-SMC) is also designed in this paper for comparison purposes. The stability of the system is analyzed using the Lyapunov stability criterion. The proposed controllers are simulated in Matlab/Simulink environment. The proposed controller shows better dynamic performance as compared to the IBS-SMC controller. Hardware in loop (HIL)-based experimental verification has been done by using the Delfino F28369D dual core microcontroller in order to prove the effectiveness of the proposed controller.

•A comprehensive overview of both analytical and electrochemical techniques for studying supercapacitors is provided.•Present knowledge on the use, advances, pros, and cons of techniques for the characterization of supercapacitors.•Different characterization techniques are classified according to the information they can provide.•The prospects and challenges associated with supercapacitors in practical applications are also discussed.

Plug-in hybrid electric vehicles (PHEVs) are considered to be a better choice than conventional hybrid electric vehicles due to environmental concerns. There are two main subsystems in the PHEVs power system namely: integrated charging unit (ICU) and hybrid energy storage system (HESS). In this work three energy sources fuel cell (FC), battery and ultra-capacitor (UC) are considered. Keeping in view of different challenging aspects like actuator limits and nonlinear nature of power conditioning circuits in ICU and HESS, design of robust nonlinear controller is still a challenge. Conventional Supertwisting Algorithm (STA) based controller exhibits wind-up effects when control signal is saturated which deteriorates the dynamic response of the controller. In order to resolve this issue, conditioning technique is used to propose conditioned Supertwisting algorithm (CSTA) based controller which mitigates the wind-up phenomenon when the control signal is saturated and exhibits better dynamic performance in the presence of external disturbances. Moreover, energy management algorithm in HESS is also presented in which State of Charge (SoC) of the battery and UC is taken as a decisive factor for the execution of rule-based strategy. Asymptotic stability of the system is proved using Lyapunov stability criterion. Simulations are performed in Matlab/Simulink ODE 45 environment which show the comparison of the proposed controller with conventional STA-based controller. The results show better performance of proposed controller when the control signals are saturated but at the same time conventional STA does not exhibit good response due to integrator wind-up. For the real-time control of PHEV, hardware in loop (HIL)-based experimental verification is also done.

Plugin hybrid electric vehicles (PHEVs) are a suitable choice to achieve enhanced performance and reduced toxic gases. The considered PHEV consists of an integrated charging unit and a hybrid energy storage system (HESS). The proposed HESS comprises of a battery with high energy density and a supercapacitor with high power density coupled together to fulfill the load demands of the vehicle. A DC–DC buck converter with an uncontrolled rectifier has been used for an on-board and balanced charging and two bi-directional DC–DC buck-boost converters have been incorporated to ensure a smooth transition of energy. A rule-based algorithm has been employed as a supervisory controller by incorporating total power inflow and state of charge of the power sources to fulfill the load demands. Moreover, a robust integral backstepping-based nonlinear controller has been designed for the smooth execution and energy management of PHEV in terms of output voltage regulation, reference generation, and smooth tracking of current. Lyapunov stability theory has been used to ensure asymptotic stability of the PHEV. The performance of the proposed controller has been validated using simulations on MATLAB/Simulink by comparing it with the Lyapunov redesign and backstepping controllers already proposed in the literature. The robustness of the proposed controller has been verified by introducing uncertainty in the state model. Finally, the real-time applicability and effectiveness of the proposed work have been ensured using controller hardware in loop (C-HIL) test bench.

Hydrogen-based electric vehicles are an important application of clean energy generation and storage systems. Fuel cell hybrid electric vehicles (FHEVs) are gaining tremendous popularity as they address both the issues; CO2emission and fuel economy crisis. FHEV under consideration consists of three sources which are fuel cell, supercapacitor and battery. Fuel cell acts as the main source, while the other two as auxiliary sources connected to the DC bus via DC–DC converters. In this paper, supertwisting sliding mode control based nonlinear controller has been designed for the hybrid energy storage system of FHEV. Moreover, fuzzy logic-based energy management unit has been implemented with proposed control design for the reduction of hydrogen consumption by utilizing maximum state of charge of battery and supercapacitor. The global stability of the system has been ensured by Lyapunov based analysis and simulated in MATLAB/Simulink® (2019a). A comparison of hydrogen fuel consumption with existing FHEVs in the literature reveals that the proposed approach successfully reduced the hydrogen fuel consumption by 29%. A robustness test has also been conducted which validates the immunity of the proposed controller to external as well as internal parametric variations. Lastly, controller hardware-in-the loop experiments have been conducted to validate the effectiveness of the proposed framework.

•The morphology of zinc sulfide nanoflakes on Ni foam was successfully controlled.•ZnS nanoflakes exhibited a high specific capacity of 650 C g−1at 2 A g−1.•Asymmetric supercapacitor device delivered high specific energy of 30 Wh kg–1.•Asymmetric supercapacitor device delivered a high specific power of 14 kW kg−1.•Asymmetric supercapacitor device illuminated 52 red LEDs for 100 s.

In this research contribution, adaptive terminal sliding mode control (ATSMC) of the hybrid energy storage system (HESS) has been proposed having fuel cell as a major source and ultra-capacitor as an auxiliary source of energy. ATSMC has been proposed to control the switching operation in the converters and adapt the unknown parameters of the system. It also ensures the rapid tracking of the current references and regulates the DC-bus voltage for higher efficiency. Moreover, nonlinear stability analysis is done to promise the system stability while simulations are done in MATLAB/SIMULINK environment using the extra-urban driving cycle (EUDC) standard. An energy management algorithm has also been proposed to ensure effective power-sharing between the two sources depending upon their nature to improve the efficiency and life span of the HESS. In the simulation results, the proposed controller has been compared with controllers given in the literature to highlight its better performance in this application. Hardware-in-loop (HIL) test bench has also been used for the real-time implementation of the proposed controller to analyze its performance.

•This work explores the importance of sulfides composite for energy storage in supercapacitors.•The synthesized NiCo2S4/WHAC composite exhibit excellent electrochemical performance.•The redox pseudocapacitive behavior of NiCo2S4/WHAC composite storage is revealed.•The capacitive contribution of NiCo2S4/WHAC composite is discussed in detail.•The synthesized material opens the door to promotion and tenure for energy storage.

•A kind of new materials, high-entropy alloys (HEAs) as an electrode.•Differences in charge storing mechanism in electrode materials.•Differences in symmetric, hybrid, and asymmetric supercapacitors.•Recent advances in HEAs as an electrode material.•Critical points to be considered for HEAs as newborn electrode materials.

The charging unit of battery electric vehicle (BEV) is one of the primary subsystems which allows its interconnection with the charging facility. Due to the nonlinear behavior of the power conditioning circuitry and its sensitivity to external disturbances, robust nonlinear controller is required to achieve various control objectives like output voltage regulation and power factor correction in grid to vehicle (G2V) mode. For this purpose, an integral backstepping sliding mode controller (IBS-SMC) and backstepping sliding mode controller (BS-SMC) is designed in order to achieve these objectives. But their responses exhibit the phenomenon of chattering which is highly undesirable and can cause heat and power losses in the system. In order to mitigate the effect of chattering, supertwisting sliding mode controller (ST-SMC) has been designed which not only reduces the effect of chattering but also exhibits a better dynamic performance in controlling the BEV charger in G2V mode. The global asymptotic stability of the system for the proposed controllers has been proved using Lyapunov stability criterion. The proposed controllers have been simulated on Matlab/Simulink in which ST-SMC has been compared with IBS-SMC and other nonlinear controllers in the literature. The robustness of the designed controllers have also been checked by adding external disturbances in the plant. The results show negligible chattering and better dynamic response of ST-SMC as compared to other controllers. To further validate the designed controller experimentally in G2V mode, hardware in the loop (HIL) simulations have been done using Delfino F28379D dual core microcontroller which further prove the effectiveness of the proposed controller for BEV charger.

•2D Cu-Ni-Co ternary oxide nanoflakes were grown from 1D long leaf arrays.•The Cu-Ni-Co oxide electrode showed a high specific capacity 1046 C g − 1at 1 A g − 1.•Cu-Ni-Co oxide showed higher capacity and rate capability than NiCo2O4and Co3O4.•The HSC device delivered specific energy 51 W h kg−1at a specific power 764 W kg−1.•The HSC device illuminated 52 parallel red LEDs for approximately 266 s.

•Three nonlinear controller for output voltage regulation for DC-DC converter and MPPT of PV has been proposed.•Using Lyapunov Stability Theory, asymptotic stability of the controller has been proved.•Tracking of maximum power from the PV array has been assured using MIMO converter.•The comparison is done with Perturb & Observe method and Fuzzy Logic controllers.

•Adaptive terminal sliding mode controller, sliding mode controller and finite time synergetic controller have been proposed for Battery-UC HEV.•The energy management algorithm using the state of charge has also been incorporated for the varying load.•Using Lyapunov Stability Theory, asymptotic stability of the controllers has been proved.•The comparison of proposed controllers has been done with others proposed in the literature in MATLAB.•Results have been verified by testing it on real-time hardware-in-loop setup.

•Mn was doped on ZnS to make a high-performance supercapacitor electrode material.•Huge temperature effect on the morphology of Mn-doped ZnS was observed.•Nanosheets exhibited a high capacitance (1905 F/g) and a long cycle life (93%).•Mn-doped ZnS//AC ASC showed a high capacitance 140 F/g and lighted 52 LEDs for 150 s.•ASC exhibited a high energy density 43.3 Wh/kg and a high power density 6.8 kW/kg.

•Fuel Cell-Supercapacitor-Battery based Hybrid Electric Vehicle ahas been considered.•Double Integral Sliding Mode non-linear controller for output voltage regulation of DC Bus in HEVs has been proposed.•Using Lyapunov Stability Theory, asymptotic stability of the proposed controller has been proved.•The comparison is done with other controllers in the literature has been given.