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As the global deployment of renewable technologies accelerate, finding efficient ways to store energy will aid in responding to shifting energy demands. A prospective option not only in harvesting solar energy but also in emission‐free heating is MOlecular Solar Thermal (MOST) energy storage. A central part of MOST applications is to develop methods to release the stored energy. Herein, the Quadricyclane (QC)‐to‐Norbornadiene catalyzed back reaction is explored in a specially designed packed‐bed reactor. Four distinctly sized and purposely synthesized platinum on activated carbon catalysts are studied to trigger the heat release from the energy‐dense QC isomer. The catalysts are fully characterized using a variety of structural, surface, and spectroscopic techniques. Parameters to optimize catalytic conversion and heat release in flow conditions are explored including particle size and packing behavior, flow rates, and molecular residence times. Moreover, using CO pulse chemisorption technique, site time yield values and a turnover number are reported. Complementary to the flow reactions, computational fluid dynamic simulations applying lattice Boltzmann methods to two catalytic packed beds of different size ranges are done to evaluate fluid‐dynamic behavior within the reactor bed to ascertain the ideal particle size and packing density for catalysis in MOST applications. [ABSTRACT FROM AUTHOR]

The multifunctionality of carbon fiber (CF) is being extensively explored. Herein, polyimide covalent organic frameworks (PI‐COFs) are grafted bound to CF to enhance their mechanical and electrochemical properties. Here, a range of COF scaffolds are grafted to the surface of CFs via a two‐step functionalization. First, melamine is tethered to the fiber surface to provide an anchoring point for the COFs followed by a "graft from" approach to grow three different sized PI‐COFs utilizing three differently sized dianhydride, PMDA to form MA‐PMDA, NTCDA to form MA‐NTCDA, and PTCDA to form MA‐PTCDA COFs. These COFs increase the capacitance of CF by a maximum of 2.9 F g−1 (480% increase) for the MA‐PTCDA, this coincides with an increase in interfacial shear strength by 67.5% and 52% for MA‐NTCDA and MA‐PTCDA, respectively. This data represents that the first‐time CF has been modified with PI‐COFs and allows access to COF properties including their porosity and CO2 capture ability while being attached to a substrate. This may lead to additional high‐value recyclability and second‐life applications for CFs. [ABSTRACT FROM AUTHOR]

A water‐soluble anthraquinone derived from alizarin, 3HAAQ, is introduced as the redox‐active material in a negative potential electrolyte (anolyte) for aqueous redox flow batteries operating at pH 14. The synthesis of 3HAAQ is carried out using the Mannich reaction, which significantly improves the solubility of the new compound, an important factor for its use in RFB. Pairing with potassium ferri/ferrocyanide positive electrolyte, this flow battery exhibits an open‐circuit voltage of 1.24 V and maintains nearly 80% of the theoretical capacity at 40 mA cm−2 current density. [ABSTRACT FROM AUTHOR]

The lack of anodes stability is one among key barriers to the widespread commercialization of sodium‐ion batteries (SIBs). This is attributed to graphite, a well‐known common anode material for a range of commercial batteries including lithium‐ion batteries (LIBs), which limits the insertion of sodium (Na) ions due to their large ionic size. Tin (Sn) has shown its potential as a suitable anode material because it exhibits high capacities in conversion and alloying reactions. However, it endures significant volumetric expansion and slower reaction rates during sodiation. To overcome these challenges, this work presents a novel anode material for SIBs where a 2D layered architecture of Sn with a hard carbon (HC) buffer layer is engineered using physical vapor deposition technique. This novel anode (SnHT/HC) exhibits a high initial capacity of 470 mAhg−1 and an exceptional retention of 438 mAhg−1 after 3000 cycles at 0.2C, with 99 % Coulombic efficiency. SnHT/HC testing at varying fast charge and discharge C‐rate of 5C, 10C, 15C, and 50C has shown promising results. Better electron transport and reduced volumetric changes are perceived to enhance the overall performance of SnHT/HC electrodes.

As the global deployment of renewable technologies accelerate, finding efficient ways to store energy will aid in responding to shifting energy demands. A prospective option not only in harvesting solar energy but also in emission‐free heating is MOlecular Solar Thermal (MOST) energy storage. A central part of MOST applications is to develop methods to release the stored energy. Herein, the Quadricyclane (QC)‐to‐Norbornadiene catalyzed back reaction is explored in a specially designed packed‐bed reactor. Four distinctly sized and purposely synthesized platinum on activated carbon catalysts are studied to trigger the heat release from the energy‐dense QC isomer. The catalysts are fully characterized using a variety of structural, surface, and spectroscopic techniques. Parameters to optimize catalytic conversion and heat release in flow conditions are explored including particle size and packing behavior, flow rates, and molecular residence times. Moreover, using CO pulse chemisorption technique, site time yield values and a turnover number are reported. Complementary to the flow reactions, computational fluid dynamic simulations applying lattice Boltzmann methods to two catalytic packed beds of different size ranges are done to evaluate fluid‐dynamic behavior within the reactor bed to ascertain the ideal particle size and packing density for catalysis in MOST applications.

Lead‐free ceramic capacitors with high energy storage density are desired. Herein, the novel (1–x)(0.9Bi0.5Na0.5TiO3‐0.1SrTi0.85Zr0.15O3)‐xNa0.95Ca0.04Li0.01Nb0.96Zr0.04O3 [(1–x)(BNT‐STZ)‐xCZNNL, x = 0.1, 0.2, 0.3, 0.4 and 0.5] ceramics are prepared via citrate combustion technology and two‐step sintering method. The dense microstructures are observed and slim hysteresis loops are realized as addition of CZNNL. The enhanced recoverable energy storage density (Wre of 2.52 J cm−3) with high efficiency (η of 80%) is obtained in 0.6(BNT‐STZ)‐0.4CZNNL ceramic under a moderate electric field of 200 kV cm−1. Moreover, excellent thermal stability (Wre varies <1% and η varies <3.5%) at 20 to 100 °C) and excellent fatigue resistance are achieved for 0.6(BNT‐STZ)‐0.4CZNNL ceramic. [ABSTRACT FROM AUTHOR]

Lead‐free ceramic capacitors with high energy storage density are desired. Herein, the novel (1–x)(0.9Bi0.5Na0.5TiO3‐0.1SrTi0.85Zr0.15O3)‐xNa0.95Ca0.04Li0.01Nb0.96Zr0.04O3 [(1–x)(BNT‐STZ)‐xCZNNL, x = 0.1, 0.2, 0.3, 0.4 and 0.5] ceramics are prepared via citrate combustion technology and two‐step sintering method. The dense microstructures are observed and slim hysteresis loops are realized as addition of CZNNL. The enhanced recoverable energy storage density (Wre of 2.52 J cm−3) with high efficiency (η of 80%) is obtained in 0.6(BNT‐STZ)‐0.4CZNNL ceramic under a moderate electric field of 200 kV cm−1. Moreover, excellent thermal stability (Wre varies <1% and η varies <3.5%) at 20 to 100 °C) and excellent fatigue resistance are achieved for 0.6(BNT‐STZ)‐0.4CZNNL ceramic. [ABSTRACT FROM AUTHOR]

The implementation of multimodal motion ensures the stable operation in complex terrain environments, thus providing an effective guarantee for system performance. The crawling‐jumping robot has the ability to navigate in various road conditions utilizing different modes of movement. However, the mobility of the current multimodal jumping robots remains somewhat constrained by their jumping capability and the recovery time after each jump. Drawing inspiration from the energy‐storage jumping mechanism of jumping beetles, a tuneable multimodal jumping robot (Tumro) capable of executing multimodal movements including wheeled locomotion and ground‐based jumping, which can achieve a jump height of up to 3 m and swiftly recover its wheeled crawling state without requiring posture correction post‐jump, is presented. Through a specific structural design, the robot can storage energy and switch motions to jump in the desired direction based on the preset angle according to actual demand. The jumping process is thoroughly analyzed, and the kinematics and dynamics models are derived in meticulous detail. In addition, the performance of the robot is comprehensively assessed from aspects of wheel action versus vertical jump capability, power consumption, and endurance across various motion modes. The simulation scene experiment demonstrates the robot's exceptional jumping capability and efficient wheeled mobility. [ABSTRACT FROM AUTHOR]

A water‐soluble anthraquinone derived from alizarin, 3HAAQ, is introduced as the redox‐active material in a negative potential electrolyte (anolyte) for aqueous redox flow batteries operating at pH 14. The synthesis of 3HAAQ is carried out using the Mannich reaction, which significantly improves the solubility of the new compound, an important factor for its use in RFB. Pairing with potassium ferri/ferrocyanide positive electrolyte, this flow battery exhibits an open‐circuit voltage of 1.24 V and maintains nearly 80% of the theoretical capacity at 40 mA cm−2 current density.

Today the integration of renewable energy production technologies into power systems brings a new challenge in terms of optimal usage of renewable. It is known that due to the discontinuous nature of renewable energy, the challenge can be associated with the presence of unwanted voltage fluctuations and power losses in power grids. This study performs optimization of the calculation of hosting capacity to determine the maximum amount of renewable energy that can be further expanded. This can be possible by energy storage deployment on the same power grids. The battery storages are expected to have power injection and absorption associated with discharging and charging of energy storages, respectively, to solve voltage fluctuations and power disturbances. Thus, to enhance the probability of distributed generation penetration, it is necessary to have optimal allocation and size during the renewable energy penetration in low-voltage distribution networks. Global optimization as a genetic algorithm (GA) method is used during hosting capacity assessment. The results show that using GA-based optimization, total cost and loss can be reduced by 38.8 and 73%, respectively. The practical results are verified by the IEEE-33 bus system. [ABSTRACT FROM AUTHOR]

In order to realize the optimal planning of grid-resource-storage for distribution networks (DNs) with high penetrated distributed photovoltaics (PVs), a cluster partition-based two-layer expansion planning for DNs is proposed. First, a comprehensive cluster partition index-based cluster partition method is proposed, which involves the indexes such as electrical distance, power balance of the cluster, and cluster size. Second, a cluster partition-based two-layer expansion planning model is proposed. In the upper layer, a line planning model for clusters is established to carry out the planning of cluster connection lines. In the lower layer, a robust source-storage planning model is established with the uncertainty of PVs and loads, and then, the optimal location and capacity of PVs and energy storages (ESs) can be obtained. In addition, the uncertainty regulation parameter is utilized to control the range of uncertainty sets, which can reduce the conservatism of the optimization. Finally, the proposed method is carried out in a real DN in China, which can effectively improve the economy of DN planning. [ABSTRACT FROM AUTHOR]

The implementation of multimodal motion ensures the stable operation in complex terrain environments, thus providing an effective guarantee for system performance. The crawling‐jumping robot has the ability to navigate in various road conditions utilizing different modes of movement. However, the mobility of the current multimodal jumping robots remains somewhat constrained by their jumping capability and the recovery time after each jump. Drawing inspiration from the energy‐storage jumping mechanism of jumping beetles, a tuneable multimodal jumping robot (Tumro) capable of executing multimodal movements including wheeled locomotion and ground‐based jumping, which can achieve a jump height of up to 3 m and swiftly recover its wheeled crawling state without requiring posture correction post‐jump, is presented. Through a specific structural design, the robot can storage energy and switch motions to jump in the desired direction based on the preset angle according to actual demand. The jumping process is thoroughly analyzed, and the kinematics and dynamics models are derived in meticulous detail. In addition, the performance of the robot is comprehensively assessed from aspects of wheel action versus vertical jump capability, power consumption, and endurance across various motion modes. The simulation scene experiment demonstrates the robot's exceptional jumping capability and efficient wheeled mobility.

In this research, an extensive exploration of bimetallic sulfide, CuZr2S4, is delved into. It involves the utilization of diethyldithiocarbamate as a sulfur source. The resulting thin film exhibits a well‐defined crystalline structure, characterized by an average crystallite size of 33 nm, indicating a commendable crystallinity of 87%. Bandgap energy through optical characterization is unveiled to be 2.5 eV, shedding light on the metal sulfide optical behavior. Furthermore, the elemental composition and chemical bonding of the thin film are elucidated using X‐ray photoelectron spectroscopy, revealing distinctive core‐level peaks associated with Cu 2p, Zr 3d, and S 2p. Electrochemical evaluations employing voltammetry measurements showcase remarkable specific capacitive performance, achieving an impressive value of 479 Fg−1. The thin film demonstrates exceptional stability over multiple cycles, underscoring its immense potential for diverse energy‐storage applications. A thorough assessment of the synthesized material's photocatalytic capabilities, namely its ability to degrade several types of environmental contaminants, is conducted. [ABSTRACT FROM AUTHOR]

Hybrid halide perovskites have emerged promising energy‐storage materials due to their high ionic and electronic conductivity. They can be used in rechargeable batteries, photo‐rechargeable supercapacitors, and other ion capacitors. In this article, the role of A‐site cations in halide perovskites on the charge‐storage mechanism in supercapacitors is verified. Three different types of halide perovskites of APbI3 (where A = MA, Cs, or FA) are investigated to unveil the role of A‐site cation in energy‐storage application. Specific capacitance increases with the increasing surface area from CsPbI3 to FAPbI3. From the three‐electrode electrochemical measurement, it is observed that the FAPbI3 has the highest specific capacitance while CsPbI3 is the lowest among all. Herein, solid‐state asymmetric supercapacitors are further fabricated using quasi‐solid‐state gel electrolyte. The specific areal capacitance is achieved over 72 mF cm−2, which is at least six times higher than the CsPbI3‐based devices due to high ionic mobility. The stability and structural charge are further investigated due to charge storage in FAPbI3 electrode by ex situ X‐ray diffraction measurement. As prepared FAPbI3 powder is in δ phase, however during charging it changes to α‐phase and becomes stable. Significant phase changes are not observed for MAPbI3 and CsPbI3 electrodes either charging or discharging cycles. [ABSTRACT FROM AUTHOR]

In this work, the dielectric, ferroelectric, energy storage, electrocaloric (EC), and pyroelectric properties of (Pb0.92La0.08)(Zr0.55Ti0.45)O3 (PLZT) thin film (704 nm) are highlighted. The temperature‐dependent dielectric measurements reveal its relaxor behavior with an excellent tunability (≈64%) and a room‐temperature dielectric constant of ≈1670 at a frequency of 1 kHz. The film demonstrates a recoverable energy storage density of 16.13 J cm−3 and an efficiency of ≈67 %, under an applied field of ≈1915 kV cm−1. The energy storage density of the film exhibits a room‐temperature fatigue endurance of 107 cycles, with a relative deviation of 13%. The EC temperature change (ΔT) and entropy change (ΔS) of 1.42 K and 3.88 J kg−1 K−1, respectively, are measured at near room temperature at 33 MV m−1. In addition, the film demonstrates a high pyroelectric coefficient of 304 μC m−2 K−1 at 293 K. These properties indicate the potential of PLZT film for high‐field energy storage, cooling, and energy‐harvesting applications. [ABSTRACT FROM AUTHOR]

Textile‐based energy storage components are paramount for establishing invisible electronic textiles that do not require conventional rigid batteries. A novel and scalable fabrication method is reported for introducing MXene (Ti3C2Tx) into activated carbon (AC) supercapacitors to enhance electrochemical performance. Supercapacitors are prepared within a single layer of textile with a phase‐inverted polymer membrane fabricated within the textile yarn structure to form a porous, flexible, and mechanically durable separator. MXene is introduced in two different forms: 1) A multilayer MXene (m‐MXene)powder is mechanically mixed with an AC slurry and deposited onto the textile. 2) Delaminated MXene (d‐Mxene) nanosheets are spray‐coated onto the surface of spray coated AC electrode. With an organic electrolyte, 1 M tetraethylammonium tetrafluoroborate in dimethyl sulfoxide, these supercapacitors are electrochemically stable between +/− 2.6 V and demonstrate a maximum areal capacitance of 148.7 mF cm−2, an energy density of 0.921 mWh cm−2, and a power density of 1.01 mW cm−2. The addition of MXenes improves the areal capacitance and by combining both approaches an improvement of 220% is achieved compared with identical supercapacitors with standard AC electrodes. The novelty of this work is to develop a scalable and straightforward solution processing method for introducing MXene into carbon supercapacitor electrodes enabling high‐performance textile‐based energy storage devices. [ABSTRACT FROM AUTHOR]

A promising method of energy storage is the combination of hydrogen and compressed-air energy storage (CAES) systems. CAES systems are divided into diabatic, adiabatic, and isothermal cycles. In the diabatic cycle, thermal energy after air compression is discharged into the environment, and the scheme implies the use of organic fuel. Taking into account the prospects of the decarbonization of the energy industry, it is advisable to replace natural gas in the diabatic CAES scheme with hydrogen obtained by electrolysis using power-to-gas technology. In this article, the SENECA-1A project is considered as a high-power hybrid unit, using hydrogen instead of natural gas. The results show that while keeping the 214 MW turbines powered, the transition to hydrogen reduces carbon dioxide emissions from 8.8 to 0.0 kg/s, while the formation of water vapor will increase from 17.6 to 27.4 kg/s. It is shown that the adiabatic CAES SENECA-1A mode, compared to the diabatic, has 0.0 carbon dioxide and water vapor emission with relatively higher efficiency (71.5 vs. 62.1%). At the same time, the main advantage of the diabatic CAES is the possibility to produce more power in the turbine block (214 vs. 131.6 MW), having fewer capital costs. Thus, choosing the technology is a subject of complex technical, economic, and ecological study. [ABSTRACT FROM AUTHOR]

Electrical conductivity is very important property of nanomaterials for using wide range of applications especially energy applications. Metal‐organic frameworks (MOFs) are notorious for their low electrical conductivity and less considered for usage in pristine forms. However, the advantages of high surface area, porosity and confined catalytic active sites motivated researchers to improve the conductivity of MOFs. Therefore, 2D electrical conductive MOFs (ECMOF) have been widely synthesized by developing the effective synthetic strategies. In this article, we have summarized the recent trends in developing the 2D ECMOFs, following the summary of potential applications in the various fields with future perspectives. [ABSTRACT FROM AUTHOR]

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The development of high‐temperature resistant dielectrics with excellent dielectric properties and self‐healing behavior is crucial for the application of metallized film capacitors. In this work, a series of polyetherimide (PEI) dielectric films are designed and fabricated. The introduction of polar groups is in favor to the increase of permittivity, and the flexible connection such as the ether group will facilitate the reduction of dielectric loss. Moreover, the oxygen elements are beneficial to the "self‐healing" of metallized film capacitors. Consequently, the permittivity of 3.53–4.00, dissipation factor of 0.281–0.517%, and Weibull breakdown strength of 347–674 MV m−1 are obtained for the PEI dielectrics. In addition, PEI‐4 (BPADA‐BAPP) and PEI‐8 (BPADA‐MDA) are selected to further investigate dielectric breakdown (150 °C), electrical displacement‐electric filed (D‐E) loop (at room temperature and 150 °C) as well as self‐healing performance, which will evaluate their potential in practical applications. The results show that PEI‐8 has stable breakdown field strength and high charge–discharge efficiency at elevated temperatures. Metallized film capacitor based on PEI‐8 exhibits excellent self‐healing performance, with pleasing self‐clear morphology, high breakdown voltage, and reduced self‐healing energy. Therefore, PEI‐8 is considered as a potential candidate for metallized film capacitors applied under harsh conditions. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) have received much attention regarding the thermal regulation of electronic devices. However, the main limitations of using organic PCMs are the low thermal conductivity and leakage during the phase change process. This work aims to improve these limitations to increase the thermal conductivity of the leakage‐proof PCM formed by a polyrotaxane that serves as a support material to encapsulate PEG. For this purpose, different contents of graphene nanoplatelets (GNP) are blended. To facilitate its postindustrial production and to meet ecological standards, the synthesis of this PCM is simple and only using water as a solvent. The PCMs can be thermally processed conveniently by a hot press. Furthermore, the PCMs achieve high enthalpy values (132.9–142.9 J g−1) due to the action of GNPs as thermally conductive fillers. The PCMs exhibited an increase of 60–257% in thermal conductivity values with higher GNP content, and show great shape stability and no leakage during phase change. These improvements solve the main problems of organic PCMs, thus making PLR‐PEG‐GNP‐based materials a good candidate for use as thermal energy storage materials in industrial applications as thermoregulators of solid‐state disks or realizing the "shaving peaks and filling valleys" effect for thermoelectric generators. [ABSTRACT FROM AUTHOR]

High entropy alloys (HEAs) are composed of five or more metal elements with similar proportions. Due to the electronic structure among metal elements, they have abundant active sites and have good catalytic activity and stability as materials. Therefore, they have great promise in electrochemical energy storage and electrocatalysis. This paper reviews the preparation and characterization methods of HEAs, and the applications of HEAs in catalysis, especially the contribution in lithium‐sulfur batteries, but also in Electrolyzed water and other energy storage materials. The challenges of HEAs in catalysis and their future developments are also presented. [ABSTRACT FROM AUTHOR]

This article reports a new approach toward fabrication and directed assembly of nanoparticulate reactive system (Nanofoils) on patterned substrates. Different from current state‐of‐the‐art, gas phase electrodeposition uses nanoparticles instead of atoms to form densely packed multilayered thin films at room temperature‐pressure. On ignition, the multilayer system undergoes an exothermic self‐propagating reaction. The numerous contact points between two metallic nanoparticulate layers aid in high heat release. Sub‐10‐nm Platinum (Pt) and Aluminum (Al) particles are synthesized through cathode erosion of metal electrodes in a flow of pure nitrogen gas (spark ablation). Pt/Al bilayer stacks with total thickness of 3–8 µm undergo self‐propagating reaction with a 10.3 mm s−1 wavefront velocity on local ignition. The reaction wavefront is captured using high speed videography. Calorimetry studies reveal two exothermic peaks suggesting Pt/Al alloy formation. The peak at 135 °C has a higher calorific value of 150 mW g−1 while the peak at 400 °C has a 12 mW g−1 exothermic peak. X‐ray diffraction study shows reaction‐products are cubic Al2Pt with small quantities of orthorhombic Al6Pt and orthorhombic AlPt2. Electron microscopy studies help draw a correlation between film morphology, bimetallic interface, nanoparticle oxidation, and self‐propagating reaction kinetics that is significant in broadening our understanding towards nanoparticulate reactive systems. [ABSTRACT FROM AUTHOR]

Ultrathin, breathable, and skin‐compatible epidermal electronics are attractive for wearable and implantable healthcare and biomedical applications. However, materializing and integrating all electronic components on ultrathin platforms is still challenging. Here, a charge‐storing electronic tattoo (E‐tattoo) device with ultrathin, breathable, and skin‐compatible properties is reported. Silk protein nanofibers (SNFs) and carbon nanotubes (CNTs) form the top and bottom electrodes that sandwich the intermediate dielectric layer fabricated using poly(vinyl alcohol) nanofibers. The E‐tattoo capacitors on the deformed skin, show excellent mechanical and electrical stability, and 60 µm‐thick capacitors exhibit frequency‐dependent capacitances (up to 350 pF at 5 kHz) and capability for memory operation. Mechanical bending induces capacitance change, which increases as the bending radius is decreased, indicating mechanical sensing capability of the E‐tattoo. SNF/CNT‐based triboelectric nanogenerator E‐tattoos can be connected to the capacitor E‐tattoo, and the charges generated by multiple bare‐finger touches can be stored in the capacitor (0.23 V for 200 touches). Due to the micro/nanopores in the NF networks, the device exhibits a water vapor transmission rate of 115.04 g m−2 d−1, which is better than that of a commercial band‐aid, as well as ethanol sensing capability. Developed E‐tattoo capacitor can be used for constructing multicomponent integrated ultrathin and epidermal electronics. [ABSTRACT FROM AUTHOR]

Zinc‐based flow batteries are promising for distributed energy storage due to their low‐cost and high‐energy density advantages. One of the most critical issues for their practical application is the reliability that results from the heterogeneous zinc deposition and dead zinc from falling off the electrode. Herein, nitrogen‐doped carbon nanotubes (N‐CNTs)‐based composite membrane through a facilely partially embedded method is reported to enable a dendrite‐free alkaline zinc‐based flow battery. The results indicate that the electrically conductive N‐CNTs functional layer can enhance the transport dynamics of charge carriers and homogenize electric field distribution in membrane–electrode interface, which induces the initial nucleation of metallic zinc from the carbon felt electrode to N‐CNTs functional layer and further achieve a uniform and dense plating of metallic zinc in alkaline media. Thus, the engineered membrane enables a stable alkaline zinc–iron flow battery performance for more than 350 h at a current density of 80 mA cm−2. Moreover, an energy efficiency of over 80% can be afforded at a current density of 200 mA cm−2. The scientific finding of this study provides a new strategy on composite membranes design and their capability to adjust the plating of metallic zinc in alkaline media. [ABSTRACT FROM AUTHOR]

Tiny autonomous systems less than 1 mm across need small energy storage to satisfy the demand for temporary pulse power and consistent power supply. A battery or supercapacitor alone cannot meet both requirements. Integration of battery and supercapacitor is an alternative, but it introduces a device (supercapacitor) that is not frequently invoked but requires substantial space. Herein, a submillimeter (0.42 mm2) high‐power supercapacitor with an additional function, namely, an on‐chip integrated probe for biomolecule detection is created. The dual‐function device is directly used in the liquid electrolyte, and its Swiss‐roll geometry allows for operation in a minimum 12‐nL electrolyte. The micro‐Swiss‐roll supercapacitor delivers a power density of 911 mW cm−2 and displays a 98% capacitance retention over 10 000 cycles. The biomolecule probe achieves a sensitivity of 230–262 µA mm−1 with a limit of detection of 0.4–0.5 × 10−3m for the proof‐of‐concept target, the neurotransmitter dopamine. The biomolecule probe achieves a 230–262 µA mm−1 sensitivity with a limit of detection of 0.4–0.5 × 10−3m for the proof‐of‐concept target, the neurotransmitter dopamine, along with selectivity in the presence of ascorbic acid. The independent dual function provides a promising route toward the full‐time use of dust‐sized supercapacitors integrated into submillimeter functional systems. [ABSTRACT FROM AUTHOR]

Zn–air fuel cells are promising energy storage devices for renewable energy and power sources, as they are cost‐effective and have high energy density. However, limited charge and discharge cycles and low round‐trip efficiency have long been obstacles to large‐scale market deployment. Herein, a new fluidized‐bed zinc–air fuel cell is designed, constructed, tested, and characterized. The integration of the fluidized bed in the zinc–air fuel cell leads to key advantages such as: erosion of the anode passivation layer, which plays a key role in the rapid voltage decay and keeping the products of reactions away from the proximity of the electrodes, reducing the concentration overpotential, due to the concentration gradient of electrode species in the diffusion boundary layer between the electrode–electrolyte interface and the electrolyte bulk. [ABSTRACT FROM AUTHOR]

Tunable dynamic networks of cellulose nanofibrils (CNFs) are utilized to prepare high‐performance polymer gel electrolytes. By swelling an anisotropically dewatered, but never dried, CNF gel in acidic salt solutions, a highly sparse network is constructed with a fraction of CNFs as low as 0.9%, taking advantage of the very high aspect ratio and the ultra‐thin thickness of the CNFs (micrometers long and 2–4 nm thick). These CNF networks expose high interfacial areas and can accommodate massive amounts of the ionic conductive liquid polyethylene glycol‐based electrolyte into strong homogeneous gel electrolytes. In addition to the reinforced mechanical properties, the presence of the CNFs simultaneously enhances the ionic conductivity due to their excellent strong water‐binding capacity according to computational simulations. This strategy renders the electrolyte a room‐temperature ionic conductivity of 0.61 ± 0.12 mS cm−1 which is one of the highest among polymer gel electrolytes. The electrolyte shows superior performances as a separator for lithium iron phosphate half‐cells in high specific capacity (161 mAh g−1 at 0.1C), excellent rate capability (5C), and cycling stability (94% capacity retention after 300 cycles at 1C) at 60 °C, as well as stable room temperature cycling performance and considerably improved safety compared with commercial liquid electrolyte systems. [ABSTRACT FROM AUTHOR]

Functionalization of phase change capsules is recognized as one of the promising technologies to improve energy efficiency and promote their versatile application. Herein, a new magnetic phase change capsule (NiFe2O4‐encapsulated phase change material (EPCM)) composed of paraffin wax core and SiO2‐NiFe2O4 double‐layer shell is designed. The prepared NiFe2O4‐EPCMs possess sensitive magnetic response, excellent thermal management performance, and enhanced thermal stability. In particular, the representative NiFe2O4‐EPCM‐4 has the highest saturation magnetization (8.41 emu · g−1) and high enthalpy of 131.2 J · g−1. Subsequently, NiFe2O4‐EPCM‐4 is introduced into silicone rubber foam (SRF) matrix and magnetic composite SRFs (MSRFs) are prepared. The latent heat of MSRF‐3 containing 30% NiFe2O4‐EPCM‐4 can reach 28.9 J g−1 and there is almost no change even after 200 cycles. In comparison with pure SRF, the tensile strength and compressive strength of MSRF‐3 are increased by 167.7% and 941.8%, respectively. Importantly, the electromagnetic interference shielding effectiveness of MSRF‐3 is significantly improved from 15.9 to 30.6 dB. Besides, the MSR‐3 can achieve an intriguing infrared stealth function for targets both in human body temperature and high temperature environment. Therefore, this work might stimulate people's interest and inspiration in the design and preparation of multifunctional phase change capsules. [ABSTRACT FROM AUTHOR]

Abstract Ultrathin, breathable, and skin‐compatible epidermal electronics are attractive for wearable and implantable healthcare and biomedical applications. However, materializing and integrating all electronic components on ultrathin platforms is still challenging. Here, a charge‐storing electronic tattoo (E‐tattoo) device with ultrathin, breathable, and skin‐compatible properties is reported. Silk protein nanofibers (SNFs) and carbon nanotubes (CNTs) form the top and bottom electrodes that sandwich the intermediate dielectric layer fabricated using poly(vinyl alcohol) nanofibers. The E‐tattoo capacitors on the deformed skin, show excellent mechanical and electrical stability, and 60 µm‐thick capacitors exhibit frequency‐dependent capacitances (up to 350 pF at 5 kHz) and capability for memory operation. Mechanical bending induces capacitance change, which increases as the bending radius is decreased, indicating mechanical sensing capability of the E‐tattoo. SNF/CNT‐based triboelectric nanogenerator E‐tattoos can be connected to the capacitor E‐tattoo, and the charges generated by multiple bare‐finger touches can be stored in the capacitor (0.23 V for 200 touches). Due to the micro/nanopores in the NF networks, the device exhibits a water vapor transmission rate of 115.04 g m−2 d−1, which is better than that of a commercial band‐aid, as well as ethanol sensing capability. Developed E‐tattoo capacitor can be used for constructing multicomponent integrated ultrathin and epidermal electronics.

The development of advanced electrode materials for the next generation of electrochemical energy storage (EES) solutions has attracted profound research attention as a key enabling technology toward decarbonization and electrification of transportation. Since the discovery of graphene's remarkable properties, 2D nanomaterials, derivatives, and heterostructures thereof, have emerged as some of the most promising electrode components in batteries and supercapacitors owing to their unique and tunable physical, chemical, and electronic properties, commonly not observed in their 3D counterparts. This review particularly focuses on recent advances in EES technologies related to 2D crystals originating from non‐layered 3D solids (non‐van der Waals; nvdW) and their hallmark features pertaining to this field of application. Emphasis is given to the methods and challenges in top‐down and bottom‐up strategies toward nvdW 2D sheets and their influence on the materials' features, such as charge transport properties, functionalization, or adsorption dynamics. The exciting advances in nvdW 2D‐based electrode materials of different compositions and mechanisms of operation in EES are discussed. Finally, the opportunities and challenges of nvdW 2D systems are highlighted not only in electrochemical energy storage but also in other applications, including spintronics, magnetism, and catalysis. [ABSTRACT FROM AUTHOR]

Supercapacitors (SCs) have demonstrated great potential for integration into future wearable and implantable electronics, yet the insufficient environmental adaption and biosafety limit their further development. To this regard, application of biodegradable polymers is considered as an ideal solution strategy for the environmentally sound disposal of SCs. The biodegradable polymers with satisfactory degradability and excellent biocompatibility demonstrate an irreplaceable role in the future development of SCs and provide an ideal solution strategy for its environmentally sound disposal. In this review, the research progress and challenges of biodegradable polymers in the field of SCs are discussed and analyzed. First, the classification of existing biodegradable polymers and their typical structure, properties, and preparation processes are elucidated. Subsequently, the main applications of biodegradable polymers in different components of SCs, including electrodes, electrolytes, substrate, and encapsulation materials, are summarized. In addition, the research progress of biodegradable polymer‐based SCs in terms of preparation strategies and modification methods is summarized, and the key role of biodegradable polymers in the development process of green SCs is deeply discussed. Finally, the future perspectives and challenges faced by the biodegradable polymer‐based SCs are briefly proposed. [ABSTRACT FROM AUTHOR]

Covalent-organic frameworks (COFs) are emerging organic crystalline materials with a porous framework that extends into two or three dimensions. Originating from their versatile and rigorous synthesis conditions, COFs have abundant and tunable pores, large and easily accessible surfaces, and plenty of redox-active sites, making them promising material candidates for various energy storage applications. One important area is to serve as capacitive electrode materials in supercapacitors. This review provides a timely and comprehensive summary of the recent progress in the design and synthesis of COF-based or COF-derived materials for capacitive energy storage applications. The review starts with a brief introduction to COFs' structural features and synthesis methods. Next, recently reported literature is categorized and introduced following their different energy storage mechanisms and material assembly or treatment approaches. Finally, the existing challenges and future directions for realizing practical COF-based supercapacitors are discussed. [ABSTRACT FROM AUTHOR]

Nanoengineered polar oxide films have attracted much attention for electric energy storage thanks to their high energy density, though they are all deposited on thick and rigid substrates, resulting in inferior overall energy density and poor manufacturability. Herein, an alternative strategy is developed for oxide dielectrics utilizing van der Waals epitaxy on ultrathin and flexible mica substrate, with a dielectric superlattice of Pb0.92La0.08(Zr0.95Ti0.05)O3‐SrTiO3 carefully engineered to break its long‐range antiferroelectric polar order. An ultrathin flexible capacitor is obtained as a result, with a record high overall energy density of 12.19 J cm−3 and an efficiency of 90.98%, and there is much room for further improvement since mica substrate can approach 2D limit. The superlattice can be easily rolled for large‐scale manufacturing, and the energy storage performances are well maintained under large bending deformation as well as extended bending cycling. The study thus establishes a viable route for dielectric oxide films, paving way for their practical applications in high‐energy density capacitors. [ABSTRACT FROM AUTHOR]

The advent of new solid‐state energy storage devices to tackle the electrical revolution requires the usage of nonlinear behavior leading to emergent phenomena. The ferroelectric analyzed herein belongs to a family of electrolytes that allow energy harvesting and storage as part of its self‐charging features when thermally activated. The Na2.99Ba0.005ClO electrolyte shows quasi‐adiabatic behavior with a continuous increase in polarization upon cycling, displaying almost no hysteresis. The maximum polarization obtained at a weak electric field is giant and similar to the remanent polarization. It depends on the temperature with a pyroelectric coefficient of 5.37 C m−2 °C−1 from −5 to 46 °C. The emergence occurs via negative resistance and capacitance. The glass transition is found to have its origins in the sharp depolarization at 46 – 48 °C. Above –10 °C, at ≈ –5 °C, another thermal anomaly may rely on the topologic characteristics of the A3–2xBaxClO (A = Li, Na, K) glass electrolytes enabling positive feedback of the current of electrons throughout the surface of the inner cell. The phenomena may pave the way toward a better understanding of dipolar nanodomain fragile glasses with exceptional ferroelectric characteristics to architect energy harvesting and storage devices based on multivalent thermally activated Na+‐ion‐ion electrolytes. [ABSTRACT FROM AUTHOR]

• Proposes a method for energy management in the smart home (SH) by integrating PVs, ESSs, and 2-way energy flow. • Solar-based building modeling in digital twin. • Collaborate machine learning and digital twin framework for smart management of intelligent building. Increasing populations and economic expansion have substantially increased the energy requirements of residential consumers. Energy storage system (ESS) and distributed generation (DGs) are key tools for tackling this problem in smart homes. This study investigates the cost of electricity for residential consumers as a result of the combination of distributed photovoltaics (PVs) and ESSs for IoT-based smart home. Moreover, this paper examines energy management advantages due to bidirectional energy flow (H2G). In order to formulate the home energy management issue, PV and ESS end-user satisfaction limitations are taken into account. This study exploits a Q value-enabled reinforcement learning (RL) method to optimize home appliance scheduling (HAS) according to end-user priority. According to simulation outcomes, the suggested scheduling for household appliances performs well, and demand response (DR) measures have been implemented. It can be seen that the cost of electricity consumption as well as the uncertainty of the system have decreased in digital twin real-based application. [ABSTRACT FROM AUTHOR]

As one of the "miracle materials" in the 21st century, aerogels with ultra‐low weight and remarkable mechanical performance have emerged and shown incredible immunity to harsh working environments, attracting substantial research interests across a wide range of areas. Recently, exploitation of MXene nanosheets into aerogels represents a new research focus in the field of materials science, on account of their unique structures and outstanding properties. In this review, the aim is to provide a timely and insightful overview for the recent advances in the fabrication, performance, and application of MXene‐based aerogels. The main strategies for constructing MXene‐based aerogels, directly from MXene‐dispersion or in the presence of other functional components, are summarized. Furthermore, the desirable performance of MXene‐based aerogels and their related applications in the areas including electromagnetic management, sensors, solar steam generators, and energy storage are highlighted. A thorough investigation and comparison of their mechanical, electrical, sensing, and other properties are performed to understand the structure‐property relationships. At last, this study is concluded with summary and outlook section on the future development as well as challenges that remained, thus bringing new research opportunities for the material engineering and functional application of MXene‐based aerogels. [ABSTRACT FROM AUTHOR]

Dealing with multi-objective problems has several interesting benefits, one of which is that it supplies the decision-maker with complete information regarding the Pareto front, as well as a clear overview of the various trade-offs that are involved in the problem. The selection of such a representative set is, in and of itself, a multi-objective problem that must take into consideration the number of choices to show the uniformity of the representation and/or the coverage of the representation in order to ensure the quality of the solution. In this study, day-ahead scheduling has been transformed into a multi-objective optimization problem due to the inclusion of objectives, such as the operating cost of multi-energy multi-microgrids (MMGs) and the profit of the Distribution Company (DISCO). The purpose of the proposed system is to determine the best day-ahead operation of a combined heat and power (CHP) unit, gas boiler, energy storage, and demand response program, as well as the transaction of electricity and natural gas (NG). Electricity and gas are traded by MGs with DISCO at prices that are dynamic and fixed, respectively. Through scenario generation and probability density functions, the uncertainties of wind speed, solar irradiation, electrical, and heat demands have been considered. By using mixed-integer linear programming (MILP) for scenario reduction, the high number of generated scenarios has been significantly reduced. The ɛ-constraint approach was used and solved as mixed-integer nonlinear programming (MINLP) to obtain a solution that meets the needs of both of these nonlinear objective functions. [ABSTRACT FROM AUTHOR]

Binder is a crucial component in present‐day battery electrodes but commonly contains fluorine and requires coating processing using organic (often toxic) solvents. Preparing binder‐free electrodes is an attractive strategy to make battery electrode production and its end‐of‐use waste greener and safer. Herein, electrospinning is employed to prepare binder‐free and self‐standing electrodes. Such electrodes often suffer from low flexibility, and the correlation between performance and flexibility is usually overlooked. Processing parameters affect the mechanical properties of the electrodes, and for the first time it is reported that mechanical flexibility directly influences the electrochemical performance of the electrode. The importance is highlighted when processing parameters advantageous to powder materials, such as a higher heat treatment temperature, harm self‐standing electrodes due to deterioration of fiber flexibility. Other strategies, such as conductive carbon addition, can be employed to improve the cell performance, but their effect on the mechanical properties of the electrodes must be considered. Rapid heat treatment achieves self‐standing V2O3 with a capacity of 250 mAh g−1 at 250 mA g−1 and 390 mAh g−1 at 10 mA g−1 [ABSTRACT FROM AUTHOR]

Due to the unique properties which are considerably different from macro‐scale or bulk materials, 1D) nanostructures have received great interests. In particular, they have greatly contributed to building next‐generation batteries by providing beneficial features such as short ion/electron pathways, structural versatility (i.e., formation of 3D current collectors, free‐standing electrodes, and separators), and excellent stress relaxation. Owing to these definite advantages, 1D nanostructure is often followed by discovery of new electrode materials. This review provides a systematic overview of the state‐of‐the‐art research progresses on 1D nanostructures, which are extensively used for rechargeable batteries. Specifically, a brief introduction of some important 1D nanostructuring methods is started and then, in situ structural characterizations using 1D nanostructures are summarized, which allow a great step forward in atomic‐scale monitoring of reaction kinetics and observing dynamic structural evolution of electrode materials. 1D nanstructuring in solid‐state electrolytes and stabilization of metal anodes are also highlighted which are not only substantially important in current research trends for future batteries but also rarely discussed in previous reviews. At the end, critical perspective and future research direction of 1D nanoengineering for future batteries are suggested. [ABSTRACT FROM AUTHOR]

An iron complex, tris(4,4′‐bis(hydroxymethyl)‐2,2′‐bipyridine) iron dichloride is reported, which operates at near‐neutral pH with a redox potential of 0.985 V versus SHE. This high potential compound is employed in the posolyte of an aqueous flow battery, paired with bis(3‐trimethylammonio)propyl viologen tetrachloride in the negolyte, exhibiting an open‐circuit voltage of 1.3 V at near‐neutral pH. It demonstrates excellent cycling performance with a low temporal capacity fade rate of 0.07% per day over 35 days of cycling. The extended cycling lifetime is the result of low permeability and improved structural stability of the newly developed iron complex compared to that of the iron tris(bipyridine) complex. The combination of high redox potential and low capacity fade rate compares favorably with those of all previously demonstrated organic and organometallic aqueous posolytes. Extensive investigation into the possible degradation mechanisms, including post‐mortem chemical and electrochemical analyses, indicates that stepwise ligand dissociations of the iron complex are responsible for the reported capacity loss during cell cycling. This investigation provides unprecedented insight to guide further improvements of such metalorganic compounds for energy storage and conversion applications. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries (LIBs) show poor performance at temperatures below 0 °C due to sluggish reaction kinetics, hindered diffusion, and electrolyte freezing. Materials that alloy with lithium offer higher specific capacity than graphite anodes and are studied extensively at room temperature, but their low‐temperature behavior is not well understood. Here, the electrochemical and transformation behavior of three alloy materials (antimony, silicon, and tin) are investigated. It is shown that antimony is particularly well suited for low‐temperature applications due to its relatively high electrode potential and promising electrochemical stability at low temperatures. It is found that lithium‐antimony alloys can be cycled down to −40 °C with ten times higher specific capacity than graphite on the first cycle. The galvanostatic intermittent titration technique is used to understand the kinetic and thermodynamic limitations of these electrode materials at low temperatures, and X‐ray diffraction shows that electrochemical phase transformation behavior is also altered at low temperatures. Finally, it is found that the use of reference electrodes is necessary at low temperatures to avoid counter electrode effects. This investigative study provides new understanding of the behavior of alloy anodes at low temperatures and reveals the need for electrode/electrolyte optimization to enable low‐temperature LIBs. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries are a promising large‐scale electrochemical energy storage system because of their excellent cost advantage compared with lithium‐ion batteries. However, the lack of high safety, low cost, and long service life anode materials hinder its actual development. Here, a sodium titanate/titanium dioxide/C (C‐NTC) heterostructure composite is reported with oxygen vacancies (OVs) that delivers a high specific capacity of 92.6 mAh g‐1 at 5 A g‐1 after 35 000 cycles (100% capacity retention) and excellent rate performance of 54 mAh g‐1 at 20 A g‐1 when tested in combination with a Na‐metal anode. Moreover, sodium‐ion full batteries assembled with C‐NTC as the anode and Na3V2(PO4)3@C‐BN as the cathode demonstrates a high specific capacity after 5500 cycles. Electrochemical kinetic tests and density functional theory measurements confirm that the synergistic effect of heterostructure and OVs accelerate the ion/electron transfer kinetics, the stable frame structure, and solid electrolyte interphase layer ensuring the long cycle life. Ex‐situ X‐ray photon spectroscopy reveals that the generation of Ti0 by disproportionation reactions may be responsible for the degradation of Ti‐based oxide performance, which provides unique insight and guidance for the design of titanium‐based electrodes with ultra‐long cycle life. [ABSTRACT FROM AUTHOR]

This paper proposes an energy management strategy (EMS) of a reconfigurable grid-tied hybrid ac/dc microgrid (HMG) architecture for commercial building (CB) applications. This HMG architecture consists of a multi-mode configuration (MMC) with renewable-based distributed generators (DGs), energy storages (ESs), and genset. The main advantage of this architecture is its capability to reconfigure its structure based on the predicted building load power (BLP) and renewable-based DGs power. However, minimizing the building electricity cost (BEC) and maximizing the reliability index (RI) of a reconfigurable grid-tied HMG architecture is a challenging task due to the stochastic behaviors of BLP and renewable-based DGs power. In this context, the BLP and renewable-based DGs behaviors are modeled using an artificial neural network approach to predict future time slot values. Then, system level models are developed for HMG energy sources and grid-tied converters/switches. Furthermore, BEC and RI models are developed based on the dynamic pricing of grid/HMG electricity cost and supplied energy. Then, an EMS is proposed for the developed reconfigurable grid-tied HMG architecture, which consists of a two-stage control strategy, i.e., stage I and stage II. Stage I control strategy minimizes BEC and maximizes RI using multi-objective particle swarm optimization (MOPSO) and MMC. Stage II control strategy generates control signals for HMG energy sources, converters, and grid-tied converters/switches based on stage I reference signals. Historical data is used to demonstrate the effectiveness of the proposed EMS for a reconfigurable grid-tied HMG architecture. Through numerical simulation studies, it is shown that the proposed EMS is capable of reducing BEC and increasing RI by concurrently enabling MMC of a reconfigurable grid-tied HMG architecture. [ABSTRACT FROM AUTHOR]

The thermodynamics analysis of processes flowing into the storages of compressed air energy are considered in the paper. The exergy balance has been propose as the instrument for study. The main indices have been estimate: the compressed air potential, efficiencies for all elements of the scheme and air-accumulating electric station (AAES) as a whole. The study procedure demonstrated on the example of adiabatic AAES. The relation of final temperatures, specific exergy and compression work per 1000 m3 of atmospheric air to compression ratio are determined. On the base, it can concluded that adiabatic AAES has not high efficiency, but it has some advantages: simple scheme, low investment, and combined well with renewable energy sources, for instance, wind-driven plants. To raise the efficiency of an adiabatic AAES, it should be transform to diabatic type. For that it is required modify the scheme and work regime of its elements, and combined it in complex with gas turbine plants.

Superior electrochemical performance, structural stability, facile integration, and versatility are desirable features of electrochemical energy storage devices. The increasing need for high‐power, high‐energy devices has prompted the investigation of manufacturing technologies that can produce structured battery and supercapacitor electrodes with optimized charge transport. While conventional electrode production techniques are becoming increasingly obsolete and incompatible with technological developments such as wearables and flexible electronics, additive manufacturing (AM) has emerged as one of several state‐of‐the‐art tools to produce 3D‐structured electrodes with morphology control, high yield, and scalability. Herein, a comprehensive review of the major AM technologies and most recent literature about designing and manufacturing electrode materials for batteries and supercapacitors is presented. A thorough discussion of research opportunities and challenges in this promising field is also presented to introduce the potential and importance of AM to current developments involving electrode materials.

An amorphous cobalt boride alloy with high electronic conductivity is fabricated through the liquid‐phase reduction method. Benefiting from large specific surface area and hierarchical pore structure, the as‐synthesized Co‐B nanoflakes expose substantial electrochemical active sites, promote the transfer of electrons and ions, and accelerate the redox kinetic process. The as‐obtained amorphous Co‐B alloy sample displays a specific capacitance of 411 F g−1 at 0.5 A g−1, and with the current density increased to 10 A g−1, it maintains 69% of the initial capacitance. The as‐assembled asymmetric supercapacitor device reveals electrochemical properties comprising an excellent specific capacitance of 64.3 F g−1 at 0.25 A g−1, superior cyclical stability of 105% after 20,000 cycles at 3 A g−1, and maximum energy density of 22.9 Wh kg−1 at a power density of 200.3 W kg−1. This study demonstrates great potential in developing high‐conductivity materials for an asymmetric supercapacitor through utilizing an amorphous cobalt boride alloy as a promising electrode material. [ABSTRACT FROM AUTHOR]