Use In Energy Storage Devices Research Articles

Morphologically tailored NiMn2O4nanocubic material for high energy-power density asymmetric supercapacitor and non-enzymatic H2O2 sensing

Developing an advanced material for energy storage and sensors is considered a key solution to meet future energy demands and economic challenges. The inverse spinel-structured NiMn2O4 emerges as a promising electrode material for next-gen energy storage due to its notable power capability, high energy density, and excellent cyclic stability. Nanostructuring enhances features not achievable in bulk materials, with a mixed morphology of nano-cubic and nanoflakes optimizing surface-to-volume ratio for effective use in energy storage devices. The addition of PVP as a surfactant, transforms the diffusion-controlled behavior to a capacitive mechanism, enhancing energy density and cyclic stability. Electrodes exhibit a specific capacitance of 816 F g−1 at 1 A g−1 and stable cyclic behavior over 5000 cycles in 1 M KOH. The constructed ASC device shows 96% cyclic stability over 10,000 cycles, maintaining an energy density of 8.8 Wh kg−1 at 6400 W kg−1 and reaching a maximum of 36.55 Wh kg−1 at 400 W kg−1. Electronic structural characteristics explained through density functional theory (DFT) contribute insights. Furthermore, the non-enzymatic NiMn4/GCE H2O2 sensor demonstrates high sensitivity, a low detection limit, and remarkable selectivity against various biological interferences across a broad concentration range.

Fabrication of spinel SrBi2O4 nanomaterials anchored on g-C3N4 nanosheets with enhanced performance of electrode material for energy storage application

Graphitic carbon nitride (g-C3N4) material with a similar structural phase to graphite opens new opportunities in energy conversion storage systems. The g-C3N4 sheets offered many defected sites that enhanced the adsorption and diffusion of electrolyte ions. High nitrogen concentration in g-C3N4 was ideal for increasing the binding energy between metals and carbon. The stability of pseudo-active metal oxides/chalcogenides supported by carbon results in improved capacitive performance. This study used a hydrothermal route to fabricate binary SrBi2O4/g-C3N4 composite onto g-C3N4 sheets. The SrBi2O4/g-C3N4 nanocomposite was characterized through various techniques including different analytical analyses. Among all evaluated electrodes for the electrochemical experiment binary composite SrBi2O4/g-C3N4 demonstrated the highest electrochemical activity and showed the capacitive of 777.2 F g−1 at 1 A g−1. Moreover, binary composite SrBi2O4/g-C3N4 was shown to have a lesser charge transfer resistance (Rct) of 0.87 Ω as compared to other bare fabricated materials. The exceptional electrochemical capability of SrBi2O4/g-C3N4 can be due to the combined effect of SrBi2O4 and g-C3N4 which included various redox state enhanced electrode wettability and superior structural and chemical stability. The composite material shows excellent power and high energy density of 319.95 W Kg−1 and 44.20 Wh Kg−1. Based on the findings our study suggested a practical approach to fabricated hybrid electrode materials that have optimum properties for use in energy storage devices in future supercapacitors.

Effect of Salt Concentration in Water‐In‐Salt Electrolyte on Supercapacitor Applications

AbstractElectrical double‐layer supercapacitors offer numerous advantages in the context of energy storage; however, their widespread use is hindered by the high unit energy cost and low specific energy. Recently, water‐in‐salt (WIS) electrolytes have garnered interest for use in energy storage devices. Nevertheless, their direct application in high‐power devices is limited due to their high viscosity. In this study, we investigate the WIS Lithium bis(trifluoromethanesulfonyl)Imide (LiTFSI) electrolyte, revealing a high specific capacitance despite its elevated viscosity and restricted ionic conductivity. Our approach involves nuclear magnetic resonance (NMR) analysis alongside electrochemical analyses, highlighting the pronounced advantage of the WIS LiTFSI electrolyte over the WIS LiCl electrolyte at the molecular level. The NMR analysis shows that the LiTFSI electrolyte ions preferentially reside within the activated carbon pore network in the absence of an applied potential, in contrast to LiCl where the ions are more evenly distributed between the in‐pore and ex‐pore environments. This difference may contribute to the difference in capacitance between the two electrolytes observed during electrochemical cycling.

Analysis of the potential application of a residential composite energy storage system based on a double-layer optimization model

Along with the further integration of demand management and renewable energy technology, making optimal use of energy storage devices and coordinating operation with other devices are key. The present study takes into account the current situation of power storage equipment. Based on one year of measured data, four cases are designed for a composite energy storage system (ESS). In this paper, a two-tiered optimization model is proposed and is used to optimizing the capacity of power storage devices and the yearly production of the system. Furthermore, this paper performs a comparative analysis of the performance of the four cases from the energy, environmental and economic perspectives. It is concluded that this kind of energy storage equipment can enhance the economics and environment of residential energy systems. The thermal energy storage system (TESS) has the shortest payback period (7.84 years), and the CO2 emissions are the lowest. Coupled with future price volatility and the carbon tax, the electrothermal hybrid energy storage system (HESS) has good development potential. However, the current investment cost is very high, and it will not be possible to recover this cost in 10 years. Finally, it is recommended that the cost of equipment be reduced in combination with subsidies and incentives for further promotion. The research results not only fill a gap in the study area, but also provide some suggestions for further development of industry and research on user-side energy storage.

Comparison of In Situ‐Fabricated Ternary NiCoMn‐Metal–Organic Frameworks versus Slurry Deposition on Porous Ni‐Foam: A Facile Approach for Enhancing Supercapacitor Performance

Owing to the worldwide energy requirements, metal–organic frameworks (MOFs) have been extensively used as electrode material. Ternary MOFs have been of prime importance because of their characteristic of a variety of oxidation states than mono‐ and bimetallic MOFs. Herein, a novel comparison and superiority of binder‐free MOF deposition known as in situ (IN) on the substrate have been investigated over the slurry deposition method involving the excellent properties of ternary MOFs. Confirmation of MOF formation using X‐ray diffraction and investigation of its morphological features have been explored using field‐emission scanning electron microscopy. Energy dispersive X‐ray area mapping has also been integrated for conformity of uniform elemental distribution. The electrochemical properties of NiCoMn‐MOF have been investigated and the results obtained for NiCoMn deposited using IN methodology are superior due to excellent penetration of MOF inside substrate that provides the basis of excellent electrochemical properties. A specific capacitance of 1000 C g−1 at 4 A g−1 in 3‐electrode assembly has been achieved accompanied by energy and power density of 55 Wh kg−1 and 2467 W kg−1 in 2‐electrode setup. An excellent cyclic stability of about 97% has been obtained after subjecting the asymmetric supercapacitor device to 5000 charge/discharge cycles at 20 A g−1. Diffusive nature dominancy over capacitive is also observed by manipulating Dunns’ model. The superior and novel aspect of using IN deposition may pave the way for their efficient use in energy storage devices.

Experimental investigation on nucleating agent for low temperature binary eutectic salt hydrate phase change material

The melting enthalpy and melting temperature have a significant impact on the latent heat that results from phase change materials (PCMs) used for thermal energy storage. Among the PCMs that are currently on the market, inorganic salt hydrates have greater thermal conductivity and latent heat than organic PCMs. However, the problem of salt hydrates' degree of supercooling limits their use in energy storage devices. Using sodium carbonate decahydrate (SCD) and sodium phosphate dibasic dodecahydrate (SPDD), a low temperature inorganic-inorganic eutectic salt hydrate PCM with a higher melting enthalpy and intended phase transition temperature is developed in this research study. The eutectic SCD/SPDD salt hydrate PCM eutectic point and the eutectic composition of salt hydrate PCMs to operate at low temperature range is numerically determined using Schrader equation. By numerical methods we obtain the 68 wt% of SCD with 32 wt% of SPDD to exhibit eutectic SCD/SPDD composite with eutectic melting temperature of 26.2 °C and melting enthalpy of 210.6 J/g. The synthesised eutectic PCM are characterised to explore their chemical stability, latent heat, melting point and their shortcoming due to degree of supercooling. A good way to get around the problem of the supercooling degree is to disperse the nucleating agents. In order to assess the type and degree of supercooling, the produced eutectic PCM composition is experimentally evaluated at 1–10% utilising borax, alumina, and sodium sulphate dodecahydrate as nucleating agents. However, for building cooling applications PCM with minimal degree of supercooling, with the ability to release low enthalpy during discharging is an advantage.

Borax cross-linked guar gum hydrogel-based self healing polymer electrolytes filled with ceramic nanofibers towards high-performance green energy storage applications

An inventive concept towards the implementation of green energy-storing devices is the synthesis of hydrogel-based gel electrolytes from biopolymers imbued with self-healing capabilities. However, these electrolytes have drawbacks, such as low mechanical stability due to inadequate cross-linking and limited ionic conductivity compared to synthetic polymers. This work develops and characterizes a flexible self-healing hydrogel polymer electrolytes (HPEs) based on guar gum (GG) hydrogel for use in energy storage devices. Hydrogel is prepared with silicon dioxide (SiO2) nanofibers dispersed into borax-bonding cross-linked guar gum. Propylene carbonate (PC) and diethyl carbonate (DC) in equal amounts and lithium perchlorate (LiClO4) are used as plasticizers and salt, respectively. It has been found that adding nanofibers to the hydrogel and spreading them there considerably increases the ionic conductivity as evaluated by ac impedance spectroscopy. When the nanofiber concentration is 5 wt% (wt%), the hydrogel electrolytes reach their maximum room temperature ionic conductivity of 4.3 × 10−3 S cm−1. XRD, FTIR, SEM, and XPS investigations are used to explain the enhanced conductivity caused by the dispersion of nanofibers. Nanofibers also improve the self-healing abilities of materials, as demonstrated by the fact that hydrogels loaded with 5 wt% nanofibers recover from deformation more quickly than hydrogels with lower nanofiber contents. Additionally, the dispersion of nanofibers enhances the hydrogel's mechanical and thermal properties. According to electrochemical investigations and linear sweep voltammetry (LSV) graphs, hydrogel electrolytes are stable up to 4.7 V. When compared to nanofiber-free hydrogels, nanofiber-integrated hydrogel electrolytes show more excellent interfacial stability. The developed self-healing hydrogel-based polymer electrolytes exhibit outstanding promise for a range of energy storage systems, opening the way for creating high-performance and environmentally friendly energy storage solutions.

Structural, optical, dielectric, and ferroelectric properties in [formula omitted] ceramics prepared by a solvothermal reflux approach

Chromium (Cr3+) doped BaTi1−xCrxO3 (x = 0.0, 0.03, 0.06, and 0.09) ceramics were prepared by the solvothermal reflux approach. X-ray diffraction analysis confirmed the development of tetragonal structures with P4mm symmetry in the prepared samples. The SEM analysis showed that Cr3+ doping resulted in a microstructure that was dense, uniform, and had smaller grains. Surface chemical information and oxidation states were studied using X-ray photoelectron spectroscopy. The diffuse reflectance spectrum confirmed the effect of Cr3+ content on the direct optical bandgap of BaTi1−xCrxO3 samples which shifts from 3.21 eV to 2.73 eV with increasing Cr3+ content. Dielectric permittivity was found to increase in the low-frequency region with increasing Cr3+ doping content up to x = 0.06, while it decreased in the high-frequency region compared to an undoped sample. The observed behavior of permittivity might be explained in terms of the formation of oxygen vacancy defects and their effects on the polarization dynamics of the material. Moreover, the addition of Cr3+ doping had a strong effect on the ferroelectric characteristics, as seen by the formation of a pinched hysteresis loop, resulting in the improvement of energy storage properties. Based on the obtained results, the sample with x = 0.06 exhibited an enhancement of about 3.3 times in energy discharge density and 26 % in storage efficiency compared to the undoped sample. This might be due to a large difference between the values of maximum and remnant polarizations, reduced tangent loss, and a smaller grain size, which makes this material attractive for use in energy storage devices.

A strategy to boost the electrochemical properties of Ag–Fe2O3 with intercalation of MXene hydrogel

Due to the presence of several oxidation states, MXenes and their composites with different metal oxides are of significant interest for use in electrochemical energy storage devices. However, the restacking of MXene layers and weak electrical conductivity of metal oxides pose significant obstacles to their efficient electrochemical transport. To address these crucial problems, we synthesized MXene hydrogel-based composite nanomaterials. MXene stability can be significantly improved by incorporating MXene into hydrogels. MXene hydrogels have high mechanical strength, large surface areas, high electrical conductivity, high flexibility, and superb water absorbency. To effectively stop restacking and expand the surface area of the supercapacitor electrode material, a nanocomposite containing Fe2O3 nanospheres doped with silver and then entangled with cellulose-based MXene hydrogel was fabricated by a facile coprecipitation and ultrasonication procedure. The prepared nanomaterials were characterized for structural analysis via X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Electrochemical measurements were investigated in a 1 M aqueous solution of KOH, used as an electrolyte, via cyclic voltammetry, electrochemical impedance spectroscopy, and cyclic charge-discharge. It was observed that the MXene hydrogel boosted the electrochemical characteristics of the Fe2O3 nanospheres. The fabricated nanocomposite electrode exhibited an increase in specific capacitance. The obtained specific capacitance of the nanocomposite electrode was 709.4 Fg-1 (at 1 Ag-1) and exhibited capacitance retention of 84.4%. The research results revealed that the Ag–Fe2O3/MXene hydrogel nanocomposite has potential uses in energy storage devices.

EDLC performance of plasticized NBG electrolyte inserted with Ba(NO3)2 salt: Impedance, electrical and electrochemical properties

The great challenge in front of energy storage devices is to reduce the microplastics in the ocean and their potential harm to human health through drinking. The microplastics topic mainly results from the increasing usage of electronic devices and their components. Developing green electrolytes based on natural polymers and plasticizers is unique in overcoming microplastic issues. Natural beef gelatin (NBG) based plasticized polymer electrolyte films doped with barium nitrate (Ba(NO3)2) and glycerol (Gly) were fabricated using a solution casting process. The NBG electrolyte containing 12 wt.% Ba(NO3)2 and 50 wt.% Gly-has the maximum ionic conductivity, 4.87 × 10−5 S cm−1, at room temperature. The electrochemical performance of plasticized NBG:Ba(NO3)2 was examined utilizing impedance spectroscopy, with an emphasis on the dielectric characteristics and electric modulus parameters. With electrochemical stability up to 2.65 V, the plasticized specimen with the highest conducting demonstrated eligibility for use in energy storage devices. Transference number measurement (TNM) proved the dominancy of ions as a charge carrier in the plasticized NBG:Ba(NO3)2 system, yielding an electron transference number of 0.045 and an ion transference number of 0.955. The absence of redox peaks in the cyclic voltammograms suggests a capacitive charge accumulation in the plasticized electrolyte near to the electrode surface other than the Faradaic process. The triangle-shaped galvanostatic charge-discharge (GCD) plot shows a comparatively low drop voltage. The constructed electric double layer capacitor (EDLC) using activated carbon displays energy and power densities of 3.41 W/kg and 336.4 Wh/kg, respectively, at the first cycle. The EDLC performances of plasticized NBG:Ba(NO3)2 demonstrated the cell has potential industrial use as an energy storage device.

Fallen Leaves-Based Femtosecond-Laser-Induced-Graphene for High-Performance Flexible Micro-Supercapacitors

The rapid growth of wearable and portable electronics has led to the development of microscale energy storage devices. Among these devices, microsupercapacitors (MSCs) have emerged as promising flexible energy storage devices owing to their high power density, fast charge/discharge rate, and long-term cycling stability [1-4]. Flexible MSCs were mainly made from non-biodegradable synthetic polymers, resulting a massive electronic waste. Moreover, complex manufacturing processes increase production costs.To address these challenges, we present a novel approach to fabricate green and flexible MSCs using naturally fallen leaves as a carbon precursor [5]. Our method utilize ultrashort laser pulses to create highly conductive and intrinsically flexible microelectrodes without any additional materials. The laser-induced-graphene is formed on leaves in ambient air, resulting in hierarchically porous graphene with 3D mesoporous few-layer structures.Our green flexible MSCs demonstrated excellent electrochemical performance and were confirmed to work as a power sources for various applications such as LEDs and thermometers. Furthermore, our approach offers a low-cost, renewable, and environmentally friendly alternative to traditional manufacturing processes. Overall, our green and flexible MSCs have significant potential for use in energy-storage devices for flexible/wearable electronics.

Improving the efficiency of the solar water-lifting installation for irrigation in conditions of variable clouds

Relevance. In cloudy weather, the use of solar energy for power supply to consumers without the use of energy storage devices is impossible. Known electrical consumers for which power supply may be at intervals. But at these intervals, you need to supply them with a rated voltage. Such a consumer is, for example, a waterlifting installation for an irrigation system with a capacity of 3 m³/h from a depth of up to 90 m and a power consumption of 1500 W.Methods. Modeling of the process of accumulating electricity from a solar power plant and its transmission to an electric consumer.Results. It is proposed to use an electric power storage device based on supercapacitors with the return of the rated voltage to the consumer at certain intervals. At the same time, if a solar power plant produces enough energy, then the electric consumer is connected directly to it, if not enough— first the supercapacitors are charged, then the return of electricity from them. The method of calculating the capacity, charge time and the number of supercapacitors in the storage is given. The parameters of the storage device for cyclic power supply of the water-lifting installation for 60 seconds are calculated. in cloudy weather , with the supply of 50 liters of water in these intervals.

Structural evolution and energy storage properties of Bi(Zn0.5Zr0.5)O3 modified BaTiO3-based relaxation ferroelectric ceramics

A series of (1−x)BaTiO3−xBi(Zn0.5Zr0.5)O3 (x = 0–0.15) ceramics were synthesized using the conventional solid-state method. An ultrahigh recoverable energy storage density of 3.58 J/cm3 and a high energy efficiency of 90% are obtained for 0.85BaTiO3–0.15Bi(Zn0.5Zr0.5)O3 lead-free bulk ceramics under an electric field of 430 kV/cm; the energy storage density is thus enhanced by a factor of a ∼ 895% compared with that of the pure BT ceramics. Furthermore, an excellent temperature stability is obtained, with changes in the energy storage density and efficiency <5% and <0.1%, respectively, over the temperature range of 30 °C – 120 °C. These ergodic relaxor ferroelectric characteristics are attributed to the reduced grain size, the transition from the tetragonal phase to the pseudo-cubic phase, and the transformation of the domain structure from macro domains to polar nanoregions. This work provides a lead-free material for realizing high-temperature capacitors for use in energy storage devices.

Core/shell structured Ti/Si/C composite for high-performance zinc-ion hybrid capacitor

Zinc-ion capacitors (ZnIC) have focused great attention due to high intrinsic safety and their advantages in terms of environmental protection and price. However, the increase in energy and power densities still remains a challenge. Therefore, this study aims to design and fabricate novel low-cost and environmentally-friendly nanocomposite based on titania/silica/carbon used as cathode in ZnIC. The fabrication procedure involves the functionalization of TiO2 nanoparticles with APTES and glucose, followed by a hydrothermal reaction and carbonization at 600, 700, and 800 °C (Ti/Si/C-Tx, where Tx is the temperature of carbonization) to result in carbon-coated titania/silica with a core/shell architecture. In-situ Raman and X-Ray Diffractometry (XRD) analyses were conducted to elucidate the electrochemical behaviour of the material during charge-discharge cycles. The nanocomposites were electrochemically tested using cyclic voltammetry (CV), galvanostatic cycling with potential limitation (GCPL), and potentio electrochemical impedance spectroscopy (PEIS). The designed nanocomposite showed improved performance in terms of specific capacity, power, and energy densities with values of 295 F/g, 160 W/kg, and 210 Wh/kg, respectively. Ti/Si/C-700 also demonstrated a high stability retention of 85% after 10′000 cycles, indicating its potential for use in energy storage devices. Despite these promising results, further research is required to improve capacity retention at increased current densities. The key implication of this study is the potential for the development of low-cost and high-performance energy storage devices for various applications, contributing to the growth of renewable energy sources.

A Review on Flash Sintering of Graphene Oxide Films: Mechanism and Recent Advances in the Field.

This review highlights the significance of flash sintering, a photothermal route, in reducing graphene oxide (GO) films. Essentially, extensive efforts are devoted to form graphene electrodes due to its distinctive properties, such as high surface area, excellent electrical conductivity, and optical transparency, owing to which it finds widespread use in energy storage devices, wearable electronics, sensors, and optoelectronics. Thus, rapidly rising market demands for these applications necessitate the need of a technique offering ease of manufacturability and scalability for production of graphene electrodes. The solution-processed graphene electrodes (SPGEs) are promising to fulfil these requirements. Particularly, SPGEs are fabricated by reducing GO film to graphene/reduced graphene oxide (rGO) by utilizing any reduction method, such as chemical, solvothermal, electrochemical, etc. Lately, flash sintering has garnered substantial attention as a promising reduction route for rapid, clean, and green production of graphene electrodes. This review briefly describes the underlying principle, mechanism, and parameters of flash sintering to develop an insight and advantages of this method over extensively used reduction methods. The review is a systematic summarization of the electrical, optical, and microstructural properties of rGO films/electrodes fabricated using this technique.

Improving energy storage efficiency through carbon doping of niobium oxide nanomaterials derived from areca husk in redox flow batteries and supercapacitors

In this study, niobium oxide nanoparticles (NbO2) were synthesized using the hydrothermal technique and then composite with areca activated carbon (ACs) to produce activated carbon‑niobium oxide (ACs-NbO2) nanocomposite for use in energy storage devices. The surface morphology and properties were characterized using various techniques, such as FE-SEM, EDX, XRD, Raman spectroscopy, and BET. The composites were used to modify the electrode, and the electrochemical behavior was analyzed using various studies, including CV, CP, ESI, and Tafel methods. The results showed that the modified electrode improves the electrochemical performance, reversibility, faradaic redox reaction, and stability of the material compared to the untreated electrode. Additionally, the electrocatalytic activity of the composite material was tested for use in iron and vanadium redox flow batteries and its charge and discharge performance was studied using a 132 cm2 active surface area at different current densities. The results showed a significant improvement in the electrochemical performance of the VRFBs and IRFBs, with a columbic efficiency of 87 % and 89 % respectively. The electrode also displayed good life cycle stability in VRFBs and IRFBs, up to 100 cycles and 25 cycles respectively. Furthermore, the composite material was also tested for supercapacitor applications, showing a specific capacitance of 245 Fg−1 and a CE of 81 % with 77 % retention after 3000 cycles. This is a pioneering work in the field of energy storage devices as it utilizes low-cost and abundant areca husk to obtain the electrocatalyst, and the electrocatalytic activity is further improved by the NbO2 nanocomposite.

Comparison of the capacitance of MnCo2O4 supercapacitor electrode synthesized with different morphologies

In this research, manganese cobaltite (MCO) nanoparticles with different morphologies were synthesized by a simple hydrothermal method with excellent electrochemical properties. To investigate the physical features of prepared samples, XRD analysis was used to study the crystalline structure. The SEM and TEM proved that the morphology of synthesized materials formed as flake and nanoplane structures. The electrode of samples was prepared using the hydrothermal method and the electrochemical properties of samples were investigated by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), electrochemical impedance spectroscopy (EIS) and cyclic stability analysis. Results showed that the flake structures of nanoparticles revealed the highest capacitance of 1971.98[Formula: see text][Formula: see text] at 0.5[Formula: see text]Ag[Formula: see text] as well as longer stability compared to the others with the nanoplane structure. The high cyclic stability of 91.47% after 5000 cycles introduces this electrode as a durable and promising electrode for use in energy storage devices.

Gas turbine operating as part of a thermal power plant with hydrogen storages

Over the past few years, much attention has been paid to hydrogen energy. The development of hydrogen technologies leads to a reduction in the cost of both the hydrogen fuel itself and hydrogen systems, which leads to a wider use of this type of fuel in various branches of the fuel and energy complex. At the moment, the primary task is to increase the efficiency of combined cycle power units, reduce wear and tear of equipment during peak electricity consumption, reliable backup of energy supply, and reduce harmful emissions during the generation of heat and electricity. One of the modern methods for implementing these challenges is the use of energy storage devices. A new solution to this problem can be the introduction of hydrogen storage in the cycle of a thermal power plant. The article considers the modernization of a combined-cycle power unit with a gas turbine PG6111FA manufactured by « General Electric» with a rated power of 80 MW, a waste heat steam boiler manufactured by JSC « EnergoMashinostroitelny Alliance», and a steam turbine KT-33/36–7.5/0.12. During periods of night unloading, the effective efficiency of the power unit drops, so it is necessary not to unload the equipment, but to turn on the electrolyzers for the production of hydrogen fuel for further use in hydrogen fuel cells. The operating time of the hydrogen system with an electrolyzer is not limited in time, the operation of the electrolyzer takes place during night unloading periods (from 4 to 7 h a day), while the hydrogen storage works constantly, in this mode of operation, the service life is about 15 years, for stable operation it is necessary hydrogen fuel and periodic maintenance. An important component of the hydrogen system is a hydrogen battery with minimal storage losses, in contrast to traditionally installed thermal storage. Studies of the use of hydrogen storage in the circuits of thermal power plants have shown their effectiveness, including their implementation allows you to increase the efficiency, reduce the cost of own needs of the power plant, reduce emissions in the production of electricity, a leveled load schedule allows you to increase the life of the gas turbine, as the turbine works in basic mode. The use of accumulators in thermal power plants increases the competitiveness among traditional energy generation systems.

Synthesis of PMIA/MIL-101(Cr) composite separators with high Li+ transmission for boosting safety and electrochemical performance of lithium-ion batteries

Energy storage devices require separators with sufficient lithium-ion transfer and restrained lithium dendrite growth. Herein, PMIA separators tuned using MIL-101(Cr) (PMIA/MIL-101) were designed and fabricated by a one-step casting process. At 150 °C, the Cr3+ in the MIL-101(Cr) framework sheds two water molecules to form an active metal site that complexes with PF6- in the electrolyte on the solid/liquid interface, leading to improved Li+ transport. The Li+ transference number of the PMIA/MIL-101 composite separator was found to be 0.65, which is about 3 times higher than that of the pure PMIA separator (0.23). Additionally, MIL-101(Cr) can modulate the pore size and porosity of the PMIA separator, while its porous structure also functions as additional storage space for the electrolyte, enhancing the electrochemical performance of the PMIA separator. After 50 charge/discharge cycles, batteries assembled using the PMIA/MIL-101 composite separator and the PMIA separator presented a discharge specific capacity of 120.4 and 108.6 mAh/g, respectively. The battery assembled using PMIA/MIL-101 composite separator significantly outperformed both the batteries assembled from pure PMIA and commercial PP separators in terms of cycling performance at 2 C, displaying a discharge specific capacity of 1.5 times that of the battery assembled from PP separators. The chemical complexation of Cr3+ and PF6- plays a critical role to improve the electrochemical performance of the PMIA/MIL-101 composite separator. The tunability and enhanced properties of the PMIA/MIL-101 composite separator make it a promising candidate for use in energy storage devices.

FEATURES OF ORGANIZATION AND USE OF ENERGY STORAGE SYSTEMS IN DISTRIBUTION NETWORKS

The article analyzes the features and formulates recommendations for the most effective use of the energy storage systems in electrical distribution systems and microgrids in the context of expanding the use of local renewable energy sources. Information about various energy storage technologies is summarized and recommendations are formulated regarding their best applying for various applications in the electric power industry. The tasks that can and should be solved by energy storage systems in distribution networks are considered, as a result of which the expediency of forming hybrid storage systems is substantiated. Based on the analysis of the bibliography and consideration of international experience, the main problems have been identified that require further research for a reasonable choice of the structure, parameters, locations and modes of operation of hybrid energy storage systems, taking into account the specifics of the structure and operation of domestic electric distribution systems with local energy sources. Under the implementation of hybrid energy storage systems, a fundamentally new problem of determining the optimal parameters of individual components of such systems arises, which was practically not covered in published works on this issue. Additionally, difficulty in solving this task is the need for its complex solution, since, firstly, the parameters of the individual components of the hybrid energy storage system are most likely interdependent, and secondly, it is necessary to take into account the involvement of the storage systems in the solution of a number of optimization problems inherent in the electrical distribution systems. In order to facilitate the use of energy storage devices, it is advisable to create a comprehensive standard that allows you to evaluate and compare the quality and performance of different technologies, helps energy storage users justify the type and parameters, as well as optimal placement for maximum benefit.