Efficient Energy Storage Research Articles

Atomic-Level Matching Metal-Ion Organic Hybrid Interface to Enhance Energy Storage of Polymer-Based Composite Dielectrics.

In this work, a distinctive "metal-ion organic hybrid interface" (MOHI) between polyimide (PI) and calcium niobate (CNO) nanosheets was designed. The metal ions in the MOHI could achieve atomic-level matching not only with the inorganic CNO but also with the PI chains, forming uniform and strong chemical bonds. These results were demonstrated by experiment and theory calculations. Significantly, the MOHI reduced the free volume and introduced deep traps across the filler-matrix interfacial area, thus suppressing the electric field distortion in PI-based composite dielectrics. Consequently, PI-based dielectric containing the MOHI exhibited excellent energy storage performance. The energy storage densities (Ue) of the composite dielectric reached 9.42 J cm-3 and 4.75 J cm-3 with energy storage efficiency (η) of 90% at 25°C and 150°C respectively, which are 2.6 and 11.6 times higher than those of pure PI. This study provides new ideas for polymer-based composite dielectrics in high energy storage. This article is protected by copyright. All rights reserved.

Artificial neural network-based optimization of heat absorption process of phase change materials in a novel-designed finned-plate latent heat storage system

As the world transitions to more renewable and clean energy sources, energy storage systems become crucial. They assist in storing surplus energy produced during peak production times and release it when there is a high energy demand. Phase change material (PCM) based latent heat storage systems are appropriate candidates for efficient thermal energy storage. Their ability to harness the latent heat of phase transitions provides energy density, temperature control, and reduced heat loss advantages, making them well-suited for various applications. In the current research, a novel plate latent heat storage system (P-LHS) inspired by plate heat exchangers was introduced to enhance heat absorption. Besides, to facilitate the limited thermal conductivity of the PCM and increase natural convection phenomena, several fins were applied within the P-LHS system. Artificial neural network (ANN) models were exerted to anticipate the duration needed for melting of 70 % (φ = 0.7) and 100 % (φ = 1) of the PCM. The input variables of the ANN models were the fin angle (β), the distance between two fins (D), and the fin's trail angle (α). This research examined different configurations of the fins within the P-LHS system to find the optimal one. In all the designed Tests, the heat absorption and temperature distribution within the PCM were accelerated; thereby, the melting time up to φ = 0.7 and φ = 1 was reduced remarkably compared to those in the fin-less P-LHS system. Besides, for the fastest full melting of the material in the P-LHS system, the optimal design 2 (OD2) was proposed, in which the fins should have the dimensions of α = 171.450°, β = 97.540°, and D = 27.545 mm. In OD2, the time needed until the melting of 70 % of the PCM was decreased by approximately 65.68 %. While, the necessary duration for the PCM to melt entirely was 1574 s, approximately 66.80 % less than the time needed for melting the substance in the system without fins (4741 s). This reduction in melting time was about 53 min, which is a significant amount of time in energy storage systems.

Boosting Zinc Hybrid Supercapacitor Performance via Thiol Functionalization of Graphene-Based Cathodes.

Zinc hybrid supercapacitors (Zn-HSCs) hold immense potential toward the next-generation energy storage systems, effectively spanning the divide between conventional lithium-ion batteries (LIBs) and supercapacitors. Unfortunately, the energy density of most of Zn-HSCs has not yet rivalled the levels observed in LIBs. The electrochemical performance of aqueous Zn-HSCs can be enhanced through the chemical functionalization of graphene-based cathode materials with thiol moieties as they will be highly suitable for favoring Zn2+ adsorption/desorption. Here, a single-step reaction is employed to synthesize thiol-functionalized reduced graphene oxide (rGOSH), incorporating both oxygen functional groups (OFGs) and thiol functionalities, as demonstrated by X-ray photoelectron spectroscopy (XPS) studies. Electrochemical analysis reveals that rGOSH cathodes exhibit a specific capacitance (540 Fg-1) and specific capacity (139 mAhg-1) at 0.1 Ag-1 as well as long-term stability, with over 92% capacitance retention after 10000 cycles, outperforming chemically reduced graphene oxide (CrGO). Notably, rGOSH electrodes displayed an exceptional maximum energy density of 187.6Whkg-1 and power density of 48.6kWkg-1. Overall, this study offers an unprecedented powerful strategy for the design and optimization of cathode materials, paving the way for efficient and sustainable energy storage solutions to meet the increasing demands of modern energy applications.

Faradaic and Non-Faradaic Self-Discharge Mechanisms in Carbon-Based Electrochemical Capacitors.

Electrochemical capacitors (ECs) play a crucial role in electrical energy storage, offering great potential for efficient energy storage and power management. However, they face challenges such as moderate energy densities and rapid self-discharge. Addressing self-discharge necessitates a fundamental understanding of the underlying processes. This review sets itself apart from other reviews by focusing on the basic principles of self-discharge processes in carbon-based ECs, particularly examining the nature of the process and the involvement of redox reactions. This study delineates the potential conditions for various self-discharge processes and proposes plausible criteria for differentiation, complemented by mathematical modeling. Additionally, the model selection, curve fitting, and effective tuning methods are explored to control self-discharge processes.

Self-supported iron-doped nickel oxide multifunctional electrodes for highly efficient energy storage and overall water-splitting uses

Caused by complex synthesis processes, slow diffusion rates, and the formation of undesired nanostructures, it is tedious to produce a high-quality nickel oxide (NiO) electrodes for potential energy storage and water splitting applications. This paper introduces a novel chemical technique for producing self-supported iron-doped NiO electrodes having a high concentration of oxygen vacancies by utilizing different iron-based salts i.e. iron nitrate, iron chloride, iron ammonium sulfate, iron fumarate, and iron sulfate salts. After examining physical properties, the electrochemical energy storage and water splitting measurements were performed where iron nitrate precursor-mediated self-supporting Fe-NiO electrode confirms the optimum performance. Specifically, it exhibits a specific capacitance (SC) of 3302.5 Fg−1 at a current density of 5 Ag−1. The as-fabricated Fe-NiO-A//Bi2O3 asymmetric supercapacitor has a broad voltage range of 1.5 V, a remarkable volumetric-energy-density of 98.2 W hkg−1 at a power density of 900 Wkg−1, and a long-lasting cycling life with 92.6 % capacity retention after 5000 cycles at a current density of 15 Ag−1. A bifunctional Fe-NiO//Fe-NiO electrocatalyst demonstrates a current density of 10 mA cm−2 and remarkable long-term durability of 75 h without any degradation while operating at an ultra-low cell voltage of only 1.51 V, specifying importance of self-supported Fe-doped NiO electrodes for electrochemical energy storage and water splitting applications.

A multi-scale modeling of Ca-based material for solar-driven calcium-looping energy storage process: From calcination reactor to energy carrier

The calcium looping (CaL) for thermochemical energy storage possesses a great potential to promote solar thermal utilization. However, the performance of CaL, especially for the Ca-based energy carrier, cannot satisfy the expectations of industrial application, requiring enhancement between multiple length scales. Hence, a model for solar-driven CaL energy storage process, coupled by three-dimensional reactor, two-dimensional light field and one-dimensional particle models, is proposed to study the multiprocess behavior on particle flow, photothermal conversion, calcination reaction, heat-mass transfer and stress response. It is found that moving-bed reactor contributes to achieving continuous calcination and reducing particle waste, while the rapid bouncing particles inhibit the performance of single particle, with up to 45.7 % reduction in conversion. Additionally, energy carrier with stable and continuous flow normally yields high energy storage efficiency and cycle stability when the conversion of outlet particle is closed to 1 and thermal stress is less than 50 MPa.

Effect of AlN nanoparticle doping on thermophysical properties of nitrate via mechanical milling: Experimental studies and microscopic mechanisms

A compounding method based on ball milling was used to incorporate AlN into LiNO3 to effectively improve its thermal conductivity. The optimal doping ratio was determined to be 2 wt% with an increase in thermal conductivity of 112.09 % integrating the enthalpy decrease. From the perspective of molecular dynamics simulations, it is demonstrated that AlN achieves a better matching of vibrations with LiNO3 by changing its vibrational modes at the doping ratio of 2 wt% with the support of vibration density of states, overlapping energy and phonon participation ratio. When 2 wt% AlN was added, non-local vibrational modes of LiNO3 increased, which microscopically illustrated the intrinsic mechanism of 2 wt% as the optimal doping ratio. The radial distribution function was used to explain the microscopic mechanism behind the changes in the specific heat of LiNO3 concerning temperature. The reason why the enthalpy of LiNO3 would decrease after AlN added is that AlN can bind LiNO3 molecules on the surface, and LiNO3 is confined by stronger intermolecular forces, leading to a blockage of its phase change behavior. This study proposed a doping method that can uniformly disperse AlN and avoid crystallized water. It also provides a strategy for selecting the appropriate nanoaddictives for compositing in molten salts to enhance energy storage efficiency.

Typical unit capacity configuration strategies and their control methods of modular gravity energy storage plants

Modular Gravity Energy Storage (M-GES) systems are emerging as a pivotal solution for large-scale renewable energy storage, essential for advancing green energy initiatives. This study introduces innovative capacity configuration strategies for M-GES plants, namely Equal Capacity Configuration (EC) and Double-Rate Capacity Configuration (DR), tailored to optimize energy storage efficiency and stability. Through comprehensive MATLAB/Simulink simulations, we demonstrate each configuration's distinct power characteristics and operational advantages. Our findings reveal that while the EC configuration offers enhanced power accuracy and stability, it requires a larger number of units. In contrast, the DR configuration, characterized by fewer but larger units, shows a trade-off with reduced power stability. This paper contributes significantly to the field by presenting a first-of-its-kind comparative analysis of these configurations, offering insights into their practical applications and scalability. The proposed strategies and findings lay a foundation for future research and development in gravity energy storage systems, marking a step forward in pursuing sustainable and reliable energy solutions.

Biological Insights into Energy Storage Technologies

In the face of increasing energy demands and environmental concerns, the search for sustainable and efficient energy storage technologies has intensified. This review presents a holistic survey of innovative solutions by examining biological approaches. The study proceeds through three thematic sections: Biological Fuel Cells and Battery Systems, Photosynthesis and Solar Energy Storage, and Energy Generation at the Cellular Level. The first section, Biological Fuel Cells and Battery Systems describes the integration of biological processes into energy storage mechanisms. The use of biological systems and their contribution to the development of environmentally friendly and high performance energy storage technologies are discussed. In the 2nd section, Photosynthesis and Solar Energy Storage are very prominent in sustainability and energy efficiency issues in terms of both energy production and energy source food production while reducing carbon dioxide with photosynthesis-based energy storage methods. Energy production at the cellular level is discussed in the last section, Adenosine triphosphate (ATP), which is necessary for the cell to perform processes such as growth, reproduction and response to environmental stimuli, is characterized as the primary fuel. ATP production is carried out by mitochondria in animal cells and chloroplast in plant cells. Energy storage at the cellular level is carried out by molecules such as glycogen and lipids in animal cells and starch in plant cells. Considering all three issues, it has been observed that biological-based energy storage methods have numerous advantages in terms of sustainability and energy efficiency. In application areas where engineering approaches are at the forefront, it is thought that it may be possible to design more sustainable and highly energy efficient energy production systems by gaining new perspectives with biology-based simulation studies.

Poly(3-Methylthiophene)/Graphene Composite Cathode for Rechargeable Aluminum-Ion Batteries.

To reduce the dependence on traditional fossil energy, developing efficient energy storage systems is urgent. The reserves of aluminum resources in the earth's crust are extremely rich, which makes aluminum-ion batteries a promising competitor of new energy storage devices. Here, we report a poly(3-methylthiophene)/graphene (P3TH/Graphene) composite as the cathode of an aluminum-ion battery. The adjustment of polymer chain spacing by the methyl side chain provides a channel conducive to the transport of large-size AlCl4- complexes. The addition of electron donor groups also changes the electron delocalization characteristics of polymers and improves the specific capacity of the material. At the same time, the in situ composite of graphene can enhance the Π-Π interaction to form a favorable electronic transmission channel. At a current density of 200 mA g-1, the P3TH/Graphene composite showed a specific capacity of ∼150 mA g-1. The flexible structure of the polymer also guarantees the excellent rate capability of the composite.

2D and 3D Halide Perovskite‐Based Supercapacitors

AbstractMetal halide perovskites (MHPs) are extremely promising materials for energy storage applications. Among them, two‐dimensional (2D) halide perovskites attract much attention for supercapacitor applications because of exciting properties such as electronic confinement, structural flexibility, attractive performance and stability. On the other hand, owing to its low exciton binding energy and long‐range carrier transport nature, three‐dimensional (3D) halide perovskites have been employed as one of the most promising supercapacitor materials. These materials have become one of the highly promising mixed electronic‐ionic material for efficient energy storage devices. 2D and 3D MHPs have distinctive physicochemical and electrochemical characteristics, and capacity to create hetero‐structures to strengthen their electrochemical capabilities. Thus, it is important to understand synthesis, properties and various electrochemical aspects of MHPs and their super‐capacitive behaviors. This review article focuses on the extensive overview of the recent developments of MHPs which have demonstrated exciting possibilities as supercapacitor materials but relatively less explored till now. Our review article comprises of synthesis processes, opto‐electronic properties, mechanism, supercapacitor performances, challenges and opportunities in brief. This review thus thoroughly discusses the importance and intriguing aspect of 2D and 3D halide perovskites as supercapacitor materials for their futuristic energy storage applications.

Multifunctional Polyoxometalates-Based Ionohydrogels toward Flexible Electronics.

Multifunctional flexible electronics present tremendous opportunities in the rapidly evolving digital age. One potential avenue to realize this goal is the integration of polyoxometalates (POMs) and ionic liquid-based gels (ILGs), but the challenge of macrophase separation due to poor compatibility, especially caused by repulsion between like-charged units, poses a significant hurdle. Herein, the possibilities of producing diverse and homogenous POMs-containing ionohydrogels by nanoconfining POMs and ionic liquids (ILs) within an elastomer-like polyzwitterionic hydrogel using a simple one-step random copolymerization method, are expanded vastly. The incorporation of polyzwitterions provides a nanoconfined microenvironment and effectively modulates excessive electrostatic interactions in POMs/ILs/H2 O blending system, facilitating a phase transition from macrophase separation to a submillimeter scale worm-like microphase-separation system. Moreover, combining POMs-reinforced ionohydrogels with a developed integrated self-powered sensing system utilizing strain sensors and Zn-ion hybrid supercapacitors has enabled efficient energy storage and detection of external strain changes with high precision. This work not only provides guidelines for manipulating morphology within phase-separation gelation systems, but also paves the way for developing versatile POMs-based ionohydrogels for state-of-the-art smart flexible electronics.

Multiscale analysis of a seasonal latent thermal energy storage with solar collectors for a single-family building

This paper presents a comprehensive system-to-CFD multiscale analysis of a seasonal thermal energy storage (STES) system based on phase change materials (PCMs) for efficient energy storage and release for space heating. The study investigates the impact of various factors, including the geometry of the individual storage tank and the thermo-fluid dynamic parameters of the heat transfer fluid on the system performance. The work focuses on STES integration with space heating system to meet the thermal energy demands of a typical single-family building located in Naples – South Italy, typical coastline Mediterranean climate. The primary goal is to assess the behaviour of the system-integrated PCM tank and its characteristic parameters, leading to the proposal of sustainable approaches that include renewable energy sources and partially fulfil the building thermal loads. Among the Scenarios, one stands out as it achieves a better operation, allowing storage and solar collectors to cover around 69.2 % of the winter heating demand, i.e., 3.06 MWh. The study also discusses the benefits of modular system operation, as evidenced by Scenario 3, which allows for the parallel discharge of multiple LHTES tanks, leading to an enhancement in efficiency compared to other Scenarios. Results indicate that the total energy discharged by a single STES is 56.30 kWh, with a latent heat fraction released over a time of 111 h and an average temperature difference of 5.65 °C. The tank efficiency reaches a value of 90.4 %, demonstrating the effectiveness of the STES system in meeting heating demands.

High energy storage performance of (1-x)Ba0.5Sr0.5TiO3-xK0.5Na0.5NbO3 ceramics via a combined strategy of fine grains and multiphase polar nanoregions

Electrostatic dielectric capacitors have received great attention due to their ultrafast charging-discharging speed and ultrahigh power density. However, the low energy storage density and efficiency are the main obstacles to their practical applications. In this work, solid solution relaxor ceramics with different proportions of lead-free ferroelectrics Ba0.5Sr0.5TiO3 (BST) and K0.5Na0.5NbO3 (KNN) were prepared. Superior energy storage performance was achieved in the 0.7BST-0.3KNN ceramics with a breakdown strength (Eb) of 510 kV/cm, a recoverable energy storage density (Wrec) of 4.10 J/cm3, and an energy storage efficiency (η) of 80 %, which was fairly stable over the temperature range of 30–100 °C. Since multiple cations with different valence and radius coexist on the equivalent sites (A or B sites) of the solid solutions, the chemical disorder and the corresponding lattice distortion induced the coexistence of cubic, tetragonal, and orthorhombic phases, as well as the appearance of the multiphase polar nanoregions (PNRs), making the ferroelectric hysteresis loops linear. At the same time, ultrafine grains in the ceramics greatly improved the Eb. For achieving excellent energy storage performance, this work demonstrates a potential candidate of (1-x)BST-xKNN lead-free solid solution ceramics and a combined strategy of fine grains and multiphase PNRs.

Transparent, flexible capacitor for ionotronic wearable technology

Lithium chloride hydrogel enabled 99% transparency and efficiency energy storage in electrochemical capacitors.

Flat-tube solid oxide stack with high performance for power generation and hydrogen production

This study presents the design, fabrication, and evaluation of a high-performance flat-tube solid oxide cell (FT-SOC) stack, which demonstrates exceptional power generation and hydrogen production capabilities. Comprising three large-sized FT-SOCs, each with an active area of 60 cm2, the stack was tested at 750 °C. It achieved a peak power density of 1.222 W/cm2 in fuel cell (FC) mode and an electrolysis current density of 1.283 A/cm2 at an average voltage of 1.3 V in electrolysis cell (EC) mode, marking the highest reported values for FT-SOC stacks to date. These results surpass the performance of most large-sized planar SOC stacks. Post-operation analysis revealed excellent interfacial contact between components, contributing to the stack's high performance. This study underscores the potential of FT-SOCs in efficient power generation and electrolytic energy storage applications, providing insights that could facilitate their industrial application.

A novel energy recovery and storage approach based on turbo-pump for a natural gas pressure reduction station

In this research, a direct energy harvesting and storage strategy was proposed for the recovered energy from the natural gas pressure reduction station. For this purpose, a novel turbo-pump system is proposed, which consists of a turbo-expander and a water pump. The proposed plan was integrated into a gas pressure reduction station with a capacity of 300,000 Nm3/hr. In gas pressure reduction stations, a regulator reduces gas pressure, which wastes natural gas energy in the depressurization process. To recover this wasted energy, a turbo-expander has been used instead of the regulator. The designed turbo-expander shaft is connected to the pump shaft. By receiving mechanical energy from the turbo-expander, the pump transfers the water into the water towers and thus stores the energy. For this purpose, water towers with different sizes were designed and their energy storage capacity and efficiency was calculated. The obtained results showed that 15.3 GWh energy can be recovered annually, which this amount of energy is currently wasted. While harvesting this significant amount of energy from a gas pressure reduction station, emissions are also prevented. The analysis results of the designed energy storage system also showed that the total energy conversion efficiency of recovered energy from natural gas in the pressure reduction process to electrical energy in the discharge stage of the energy storage system is about 52%. Also, the average daily electrical power generated during peak consumption hours is between 0.7 and 17.9 MW. By recovering and storing wasted energy from just one gas pressure reduction station, in addition to generating electrical energy during peak hours, the emission of 4620 tons of carbon dioxide can be prevented annually. The designed energy storage system can be installed as discrete packs of energy storage in different capacities, which have high installation and flexibility.

The effect of surface-step-terrace on energy storage density and working temperature of BaZr0.2Ti0.8O3 epitaxial films

Dielectric film capacitors have been widely used in various electronic devices due to the high energy storage density and high charge–discharge speed. The energy storage performances are highly determined by the strain status of the films. Herein, we improved the energy storage performances of epitaxial BaZr0.2Ti0.8O3 film through surface-step-terrace in the vicinal substrate. It is found that the terraces in the vicinal substrate create an additional strain parallel to the terraces and a compressive strain along the out-of-plane direction. The strains result in the increase in the energy storage density of the BZT film up to 66.9 J/cm3 with an energy storage efficiency of 73.2% at room temperature, which is 2.2 times as high as that of the films on regular substrates. Moreover, the strains also lead to the reduction of the hysteresis loss and increase in the up-limited working temperature from 125 to 225 °C with an energy storage density of 52.35 J/cm3 and an efficiency of 70.25%, exhibiting excellent thermal stability. Our work demonstrates that the strains generated by vicinal substrates can improve the energy storage performance greatly and provide a method to improve the energy storage performances of dielectric thin film capacitors.

A comparative study of chemically oxidized carbon cloth and thermally treated carbon paper electrodes applied on aqueous organic redox flow batteries

Aqueous organic redox flow batteries (AORFBs) are emerging as promising candidates for efficient energy storage in grid-scale applications. In this study, we present a comprehensive analysis comparing the performance of thermally treated carbon paper and chemically oxidized carbon cloth electrodes, which have been extensively examined for their potential suitability in AORFBs. Results indicate that carbon cloth electrodes exhibit a higher concentration of oxygenated functional groups, contributing to enhanced electrochemical kinetics and improved electrochemical stability. These attributes translate to an AORFB with 62 times higher power density when compared to paper-based electrodes used. Through repeated charge-discharge cycles utilizing the BQDS║AQS model as a representative AORFB prototype, superior performance in the carbon cloth electrodes is consistently observed. Our findings even suggest the potential for optimizing the flow rate of the electrolyte to further enhance performance.

2D/2D Molybdenum Sulfo Selenides/Black Phosphorus Heterostructures for Supercapacitors and Light‐Driven Hydrogen Generation Applications

Abstract2D transition metal dichalcogenide alloys are considered as the promising duo for energy storage and catalyst for light‐driven energy conversion applications due to their novel physicochemical properties. However, heterostructuring with other 2D materials is an effective strategy to enhance the charge storage kinetics as well as comprehensive spectral light response and efficient charge separation. Herein, Molybdenum sulfo selenide (MoSSe)/black phosphorous (BP) heterostructure is synthesized by a one‐pot solvothermal technique, and energy storage and conversion efficiency are characterized. Interestingly, the fabricated symmetric supercapacitor based on the MoSSe/BP hybrid shows an exceptional capacitance of 230 mF cm−2 with an excellent energy density of 31.9 µWh cm−2 and a power density of 805.7 µW cm−2. To validate the experimental findings, Density Functional Theory (DFT) computational simulations are carried out concurrently. The lower diffusion energy barrier for electrolytic ions, in the case of hybrid MoSSe/BP compared to pristine MoSSe, supports the higher charge storage performance. Finally, MoSSe/BP nanocomposites' photocatalytic hydrogen evolution reaction (HER) performance is evaluated under 400 W of UV–vis light, with eosin Y dye acting as a sensitizer and triethanolamine acting as a sacrificial agent. The MoSSe/BP nanocomposite exhibits the maximum photocatalytic HER activity of 5718 µmol h−1 g−1, greater than the bare MoSSe nanostructure.