Search

Anode material is a crucial component of Li-ion battery influencing electrochemical performance and overall efficiency of energy storage and conversion systems. In particular, its surface properties are of decisive importance. In this work, using density functional theory in conjunction with machine-learning interatomic potentials, we calculated diffusion rates of lithium adatom and its adsorption energy on lithium, copper, and lithium–indium alloy surfaces. We compared calculated properties of chosen materials to estimate their propensity to favor dendrite growth. Our results show that copper is a less favorable environment for dendrite formation than lithium itself, while the lithium-indium alloy has the worst surface properties, which can most likely lead to the formation of dendrites. The performed set of calculations can be used as an initial assessment of the suitability of the material for the role of anode. [ABSTRACT FROM AUTHOR]

Binary solvent electrolytes can provide interpretations for designing advanced electrolytes of next generation batteries. This study investigates the adsorption mechanisms of solvated lithium ions in binary solvents near charged electrodes. Molecular dynamic simulations are performed for lithium hexafluorophosphate (LiPF6) in ethylene carbonate and dimethyl carbonate (EC:DMC) solvent sandwiched between two electrodes. Results show that lithium ions form a tetrahedral solvation structure with two EC and two DMC molecules. The solvated lithium ion shows anti-electrostatic interaction with electrodes. This can be attributed to the electrostatic attraction of the polar end of the DMC molecule, which keeps the cation anchored to the positive electrode. Meanwhile, the solvation structure adopts a fix orientation at the negative electrode, which leads to unchanged electrostatic interaction at high charge density. Finally, EC molecules are swapped by DMC molecules near the negative electrode at high charge density. This leads to a decrease in local relative permittivity and, therefore, a decrease in differential capacitance. The differential capacitance of the positive electrode continuously decreases with increasing charge density. This is caused by the partial anchoring of solvent molecules holding the cations, which cancels the adsorption of anions near the positive electrode. This study provides insights into designing better electrolytes for efficient battery performance. [ABSTRACT FROM AUTHOR]

Both large spontaneous polarization and high breakdown strength are necessary to achieve high recoverable energy density in capacitors. Unfortunately, there is a trade-off between them within the homogeneous medium. Therefore, a sandwich structure with a high polarization layer was designed in the Aurivillius phase lead-free film to address this issue. This strategy can effectively enhance the polarization capability by introducing a highly spontaneous polarization layer and also improve the breakdown strength by reducing the leakage current caused by interfacial barriers and grain refinement. Benefiting from the synergistic effects, a high energy density of 50.4 J / cm 3 with a high efficiency of 76.6% in the sandwich-structure thin film capacitors were achieved. In addition, the energy storage performance exhibits good wide frequency range and high-temperature stability. This approach is generally applicable to the design of other ferroelectrics and dielectrics promises high-performance energy storage capacitors. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries hold great promise as energy storage systems, but the shuttle effect of lithium polysulfides (LiPS) and large volume variation limit their capacity and cycle life. We have developed CoFe alloy wrapped in N-doped porous carbon spheres (e-CF@NC) with a core–shell structure through simple copolymerization and pyrolysis. The nitrogen-doped porous carbon shell provides electron and ion transport channels and more active sites for electrolyte ion adsorption. The high chemically stable carbon can limit the segregation of polysulfides, further improving the battery cycling stability. Besides, the inside CoFe alloy particles catalyze the conversion between LiPS and Li2S, speeding up reaction kinetics and reducing solvation of active sites. Consequently, lithium–sulfur batteries with e-CF@NC-2 as the cathode display a high initial specific capacity of 1146 mA h g−1 at 0.1 C, excellent rate performance (891 mA h g−1 at 1 C, 741 mA h g−1 at 2 C), and satisfied cycle stability (average capacity decay rate of 0.033% per cycle at 1 C for 300 cycles), demonstrating significant application potential. [ABSTRACT FROM AUTHOR]

Modeling solvation dynamics and properties is crucial for developing electrolytes for electrochemical energy storage and conversion devices. This work reports an on-the-fly multi-objective Bayesian optimization (OTF-MOBO) method to parameterize force fields for modeling ionic solvation structures, thermodynamics, and transport properties using molecular dynamics simulations. By leveraging solvation-free energy and solvation radii as training data, we employ the data-driven OTF-MOBO algorithm to actively optimize the force field parameters. The modeling accuracy was evaluated in molecular dynamics simulations until the Pareto front in the parameter space was reached through minimized prediction errors in both solvation-free energy and solvation radii. Using transition metal redox ions (Fe3+/Fe2+, Cr3+/Cr2+, and Cu2+/Cu+) in aqueous solution as examples, we demonstrate that simple force fields combining the Lenard–Jones potential and Coulombic potential can achieve relative error below 2% in both solvation free energy and solvation radii. The optimized force fields can be further extrapolated to predict solvation entropy and diffusivities with relative error below 10% compared with experiments. [ABSTRACT FROM AUTHOR]

With increasing environmental concerns and energy crisis, a variety of renewable energy sources (RES) are being increasingly utilised worldwide. However, the integration of RES such as wind power and photovoltaics in large-scale can lead to increased load fluctuations, which can undermine the overall environmental benefits and pose risks to the secure and stable operation of the power system. To mitigate this challenge, a two-stage electricity production scheduling is developed incorporating energy storage system (ESS) and dynamic emission modelling (DEM). In the first stage, a multi-objective mixed integer programming model schedules the production of RES, increasing penetration rate and system stability. In the second stage, a data-driven dynamic emission model is developed to optimise the load allocation of thermal power unit to reduce the carbon emissions. Furthermore, a flexible operating reserve strategy is proposed to handle the uncertainty resulting from the intermittent character of RES. Experimental results demonstrate that the proposed method effectively schedules the production of RES thereby alleviating the contradiction between high RES utilisation and stable system operation. Compared to the benchmark model, the proposed method can reduce the carbon emissions and total cost of the system by 20.34% and 10.65%, respectively. [ABSTRACT FROM AUTHOR]

In the pursuit of reliable energy storage solutions, the significance of engineering electrodes cannot be overstated. Previous research has explored the use of surface modifiers (SMs), such as single-side fluorinated graphene, to enhance the thermodynamic stability of ion intercalation when applied atop few-layer graphene (FLG). As we seek alternatives to lithium-ion batteries (LIBs), earth-abundant elements like sodium and potassium have emerged as promising candidates. However, a comprehensive investigation into staging intercalation has been lacking thus far. By delving into staging assemblies, we have uncovered a previously unknown intercalation site that offers the most energetically favorable binding. Here, we study the first three elements in both alkali (Li, Na, K) and alkaline (Be, Mg, Ca) earth metals. Furthermore, the precise mechanism underlying this intercalation system has remained elusive in prior studies. In our work, we employed density functional theory calculations with advanced hybrid functionals to determine the electrical properties at various stages of intercalation. This approach has been proven to yield more accurate and reliable electrical information. Through the analysis of projecting density of states and Mulliken population, we have gained valuable insights into the intricate interactions among the SM, ions, and FLG as the ions progressively insert into the structures. Notably, we expanded our investigation beyond lithium and explored the effectiveness of the SM on ions with varying radii and valence, encompassing six alkali and alkaline earth metals. Additionally, we discovered that the number of graphene layers significantly influences the binding energy. Our findings present groundbreaking concepts for material design, offering diverse and economically viable alternatives to LIBs. Furthermore, they serve as a valuable reference for fine-tuning electrical properties through staging intercalation and the application of SMs. [ABSTRACT FROM AUTHOR]

Although K0.5Na0.5NbO3 (KNN) possesses large maximum polarization and relatively high breakdown strength, the large remnant polarization constrains their practical applications as energy storage materials. In this work, through multi-element doping, (K0.5−0.5xNa0.5−0.5xBix)(Nb1−xSn0.2xZn0.6xTa0.2x)O3 relaxor ferroelectrics were prepared. As the superparaelectric states (SPE) were adjusted to room temperature, orthorhombic, tetragonal, and cubic phases coexisted, accompanied by the highly dynamic polar nanoregions (PNRs). In particular, a high recoverable energy storage density of 4.5 J/cm3 and an energy storage efficiency of 83% were achieved for the x = 0.125 ceramic, with the variations less than 11% and 4%, respectively, in the wide temperature range of 20–180 °C. These results demonstrate that the multiphase PNRs in the SPE state is an effective strategy for improving the energy storage performance of KNN-based ceramics. [ABSTRACT FROM AUTHOR]

The development of lithium-ion battery technology has ensured that battery thermal management systems are an essential component of the battery pack for next-generation energy storage systems. Using dielectric immersion cooling, researchers have demonstrated the ability to attain high heat transfer rates due to the direct contact between cells and the coolant. However, feedback control has not been widely applied to immersion cooling schemes. Furthermore, current research has not considered battery pack plant design when optimizing feedback control. Uncertainties are inherent in the cooling equipment, resulting in temperature and flow rate fluctuations. Hence, it is crucial to systematically consider these uncertainties during cooling system design to improve the performance and reliability of the battery pack. To fill this gap, we established a reliability-based control co-design optimization framework using machine learning for immersion cooled battery packs. We first developed an experimental setup for 21700 battery immersion cooling, and the experiment data were used to build a high-fidelity multiphysics finite element model. The model can precisely represent the electrical and thermal profile of the battery. We then developed surrogate models based on the finite element simulations in order to reduce computational cost. The reliability-based control co-design optimization was employed to find the best plant and control design for the cooling system, in which an outer optimization loop minimized the cooling system cost while an inner loop ensured battery pack reliability. Finally, an optimal cooling system design was obtained and validated, which showed a 90% saving in cooling system energy consumption. [ABSTRACT FROM AUTHOR]

Electrochemical interfaces are central to the function and performance of energy storage devices. Thus, the development of new methods to characterize these interfaces, in conjunction with electrochemical performance, is essential for bridging the existing knowledge gaps and accelerating the development of energy storage technologies. Of particular need is the ability to characterize surfaces or interfaces in a non-destructive way with adequate resolution to discern individual structural and chemical building blocks. To this end, sub-diffraction-limit low-energy infrared optical probes that exploit near-field interactions within atomic force microscopy platforms, such as pseudoheterodyne nanoimaging, photothermal nanoimaging and nanospectroscopy, and nanoscale Fourier transform infrared spectroscopy, are all powerful emerging techniques. These are capable of non-destructive surface probing and imaging at nanometer resolution. This review outlines recent efforts to characterize ex situ,in situ,andoperando electrode materials and electrochemical interfaces in rechargeable batteries with these advanced infrared near-field probes.

Antiferroelectric thin films have attracted blooming interest due to their potential application in energy storage areas. Pb(1−3x/2)LaxHfO3 (PLHO-x, x = 0–0.05) thin films were fabricated on Pt(111)/TiO2/SiO2/Si substrates via the chemical solution deposition method. The x-ray diffraction and high-resolution transmission electron microscopy results show that the doping of La3+, which has a smaller ion radius, leads to a slight decrease in the lattice constant and unit cell volume, which can induce the lattice distortion. In addition, the dielectric and polarization properties indicate that with an increase in the temperature or La3+ content, the antiferroelectric (AFE) I phase can transform into an AFE II phase, exhibiting a slimmer P–E loop with enhanced switching field and more pronounced polarization dispersion. Notably, PLHO-0.04 showcases excellent energy storage performance (55 J/cm3, at 2.8 MV/cm). This material also exhibits good thermal, frequency, and fatigue stability. These results suggest that the energy storage performance of PbHfO3-based films can be enhanced through the phase structure design, presenting a valuable approach to fulfill the growing demand for advanced energy storage devices. [ABSTRACT FROM AUTHOR]

For photoelectrochemical water splitting, tungsten trioxide (WO3) films with a monoclinic structure were synthesized on fluorine-doped tin oxide coated glass substrates with a vacuum evaporation method. To control the WO3 film thickness from 0.42 to 5.6 μm, the crystal orientation was intergraded from the (200) crystal plane to the (002) one. In x-ray diffraction measurements, the intensity ratio of the (002) crystal plane to the (200) one was defined as rp. In the WO3 photoelectrode with higher (002)-preferred orientation, the photocurrent continued to flow even when the incident light against the photoelectrode was completely blocked after the irradiation for 60 s. This suggests that hydrogen continues to be produced owing to the electrons charged by the formation of a hydrogen tungsten bronze (HxWO3) phase. After 72 s, the photocurrent density of the WO3 photoelectrode with rp = 42 became one-tenth of the value before the incident light was blocked. This charge release time was remarkably long compared to those of the WO3 photoelectrodes with (200)-preferred orientation and non-orientation. Therefore, it was considered that the hydrogen ion diffusion through the defects in the WO3 crystals tends to occur in the [002] crystal direction. However, the improvement in the (002)-preferred orientation can facilitate the structural change from the WO3 phase to the HxWO3 one for the entire film. [ABSTRACT FROM AUTHOR]

Polymer dielectrics with excellent capacitive performance are urgently needed in advanced electrical and electronic systems. However, due to the dramatic increase in the conduction loss, the energy density and efficiency of polymers degrade severely at elevated temperatures, limiting their application in harsh environments up to 150 °C. Herein, an all-organic polyurea (PU)/polyetherimide (PEI) blend film is designed to prepare high-temperature polymer dielectric. It is found that carrier traps can be introduced by blending, and the hydrogen bond between PU and PEI increases the trap depth, leading to suppressed leakage current and enhanced breakdown strength, thus improving the energy storage performance. PU/30%PEI exhibits a high discharged energy density of ∼3.74 J/cm3 with an efficiency higher than 90% at 150 °C, which is 78% and 70% higher than pristine PU and PEI, respectively. This work provides a facile strategy to improve the energy storage performance of polymer dielectrics by introducing deep traps through blending. [ABSTRACT FROM AUTHOR]

In the pursuit of sustainable energy solutions, the development of materials with efficient hydrogen and methane storage capacities is imperative, particularly for advancing hydrogen-powered vehicles. Metal–organic frameworks (MOFs) have emerged as promising candidates to meet the stringent targets set by the Department of Energy for both hydrogen and methane storage. This study employs Grand Canonical Monte Carlo simulations to investigate the usable hydrogen and methane gravimetric and volumetric storage capacities of the recently synthesized SIGSUA. A comparative analysis encompasses the selected MOFs with similar metal compositions, those with comparable density and average pore radius, and classical benchmarks, such as IRMOF-15 and IRMOF-20, all evaluated at room temperature and moderate pressures ranging from 25 to 35 MPa. The results reveal that SIGSUA demonstrates noteworthy gravimetric and volumetric storage capacities for both hydrogen and methane, rivaling or surpassing those of the selected MOFs for analysis. These findings underscore the potential of SIGSUA in advancing clean energy storage technologies. [ABSTRACT FROM AUTHOR]

MXene is investigated as an electrode material for different energy storage systems due to layered structures and metal-like electrical conductivity. Experimental results show MXenes possess excellent cycling performance as anode materials, especially at large current densities. However, the reversible capacity is relatively low, which is a significant barrier to meeting the demands of industrial applications. This work synthesizes N-doped graphene-like carbon (NGC) intercalated Ti3C2Tx (NGC-Ti3C2Tx) van der Waals heterostructure by an in situ method. The as-prepared NGC-Ti3C2Tx van der Waals heterostructure is employed as sodium-ion and lithium-ion battery electrodes. For sodium-ion batteries, a reversible specific capacity of 305 mAh g-1 is achieved at a specific current of 20 mA g-1, 2.3 times higher than that of Ti3C2Tx. For lithium-ion batteries, a reversible capacity of 400 mAh g-1 at a specific current of 20 mA g-1 is 1.5 times higher than that of Ti3C2Tx. Both sodium-ion and lithium-ion batteries made from NGC-Ti3C2Tx shows high cycling stability. The theoretical calculations also verify the remarkable improvement in battery capacity within the NGC-Ti3C2O2 system, attributed to the additional adsorption of working ions at the edge states of NGC. This work offers an innovative way to synthesize a new van der Waals heterostructure and provides a new route to improve the electrochemical performance significantly.

An increasingly decarbonized yet resilient power grid requires the corresponding build-out of dispatchable zero-emission resources to supply peak power. However, there is a recognized dearth of solutions which can serve multi-day peak demand events both cost-effectively and with near-term deployability. Here, we find that pairing low-cost automotive fuel cells with hydrogen storage in salt caverns can serve as a peaker plant at less than 500 US$/kW at present, a fraction of the cost of conventional fossil fuel-fired peakers. We demonstrate the peakers value for long duration storage by comparing it with pumped hydro and assessing its profitability within Texas energy-only market region. Although deployment of these peakers is constrained by the presence of salt caverns, we show that a number of sites in the United States and Europe are endowed with suitable salt formations, while utilizing hydrogen storage in pressurized containers could form a location-agnostic peak power solution.

Rechargeable multivalent-ion batteries are attractive alternatives to Li-ion batteries to mitigate their issues with metal resources and metal anodes. However, many challenges remain before they can be practically used due to the low solid-state mobility of multivalent ions. In this study, a promising material identified by high-throughput computational screening is investigated, ε-VOPO4, as a Mg cathode. The experimental and computational evaluation of ε-VOPO4 suggests that it may provide an energy density of >200 Wh kg-1 based on the average voltage of a complete cycle, significantly more than that of well-known Chevrel compounds. Furthermore, this study finds that Mg-ion diffusion can be enhanced by co-intercalation of Li or Na, pointing at interesting correlation dynamics of slow and fast ions.

AgNbO3 (AN)-based lead-free antiferroelectric ceramics are widely studied for their use as dielectric capacitor materials. In this study, Eu3+-doped AN ceramics were prepared and the results show that Eu3+ diffused into the AN lattice. The ceramics were formed by M1 and M2 phases coexisting at room temperature, as distinct from the M1 (M: monoclinic) phase of pure AN. Electrical properties and structural characterization showed that the antiferroelectric stability of the ceramics increases with the increase in Eu3+ levels. At room temperature, Ag0.94Eu0.02NbO3 ceramic exhibited a good energy storage density of 5.3 J/cm3 and a high efficiency of 71.9%. When the temperature rises from room temperature to 140 °C, the efficiency of the sample decreases from 80.4% to 67.1% and Wr decreases from 2.1 to 2.0 J/cm3, which indicates that the sample has good temperature stability. The time constant (t0.9) of this sample was less than 60 ns and the power density (PD) was 51.3 MW/cm3, indicating excellent charge–discharge capabilities. This novel ceramic is expected to be used as a new dielectric capacitor material for pulsed power supplies. [ABSTRACT FROM AUTHOR]

The global demand for high energy density batteries, mostly for application in electric vehicles, offering increased durability, safety, and sustainability is growing rapidly. In the past, this demand has been met primarily by the development and/or improvement of new/established battery materials and technologies. The high-entropy design concept—aiming at increasing chemical complexity/occupational disorder—has recently been introduced into the field of electrochemical energy storage. Various high-entropy battery materials that are seemingly capable of outperforming low-entropy counterparts by offering desirable properties have been reported. However, future studies are required to explore if the concept is broadly applicable and can be extended to all types of battery materials, especially those that are of industrial relevance. Herein, we provide a brief overview of the existing high-entropy anodes, cathodes, and solid/liquid electrolytes for use in rechargeable Li- or Na-ion batteries and discuss potential research directions and opportunities. [ABSTRACT FROM AUTHOR]

Dielectric capacitors prepared by antiferroelectric (AFE) materials have the advantages of large power density and fast discharge ability. It has been a focus on the improvement of the recoverable energy density (Wrec) and discharge energy–density (Wdis) in the AFE ceramics. To address the above issue, optimizing the proportion of components is proposed for enhancing ceramic antiferroelectricity, ultimately improving the breakdown strength (Eb) and Wrec. In this work, an ultrahigh Wrec (14.3 J/cm3) with an excellent energy efficiency (η) of 81.1% is obtained in (Pb0.96Sr0.02La0.02)(Hf0.9Sn0.1)O3 AFE ceramic at electric field of 490 kV/cm, which is the maximum value reported in lead-based AFE ceramics fabricated by the conventional solid-state reaction method so far. The multistage phase transition induced by the electric field is observed in the polarization–electric field (P–E) hysteresis loops. Furthermore, an outstanding power density (PD) of 335 MW/cm3 and an excellent Wdis of 8.97 J/cm3 with a rapid discharge speed (102 ns) are obtained at electric field of 390 kV/cm. In addition, (Pb0.96Sr0.02La0.02)(Hf0.9Sn0.1)O3 ceramics also possess an excellent thermal and frequency stability. These exceptional properties indicate that (Pb0.98−xSrxLa0.02)(Hf0.9Sn0.1)O3 ceramics are a potential candidate for pulsed power devices and power electronic devices. [ABSTRACT FROM AUTHOR]

Increasingly, society requires high power, high energy storage devices for applications ranging from electric vehicles to buffers on the electric grid. Supercapacitors are a promising contribution to meeting these demands, though there still remain unsolved practical problems. Molecular dynamics simulations can shed light on the relevant molecular level processes in electric double layer capacitors, but these simulations are computationally very demanding. Our focus here is on the algorithmic complexity of the constant potential method (CPM), which uses dedicated electrostatics solvers to maintain a fixed potential difference between two conducting electrodes. We show how any standard electrostatics solver—capable of calculating the energies and forces on all atoms—can be used to implement CPM with a minimum of coding. As an example, we compare our generalized implementation of CPM, based on invocations of the particle–particle–particle–mesh routine of the Large-scale Atomic/Molecular Massively Parallel Simulator, with a traditional implementation based on a dedicated re-implementation of Ewald summation. Both methods yield comparable results on four test systems, with the former achieving a substantial gain in speed and improved scalability. The step from dedicated electrostatic solvers to generic routines is made possible by noting that CPM's traditional narrow Gaussian point-spread of atomic charges on the electrodes effectively endows point-like atoms with chemical hardness, i.e., an intra-atomic energy quadratic in the charge. [ABSTRACT FROM AUTHOR]

VO2 polymorphs present a unique opportunity to unravel diverse electronic properties possessed by their metastable phases. A highly reproducible, single-phase, and inexpensive synthesis method is challenging for obtaining VO2 polymorphs. Recent years have witnessed some exciting success in the growth and application of a wide range of VO2 polymorphs. This comprehensive review article delves into different polymorphs, including VO2(x) (x = A, B, M, R, C, P, and D), and investigates their distinct physical attributes. The primary focus of this article centers on providing a thorough overview of the recent progress made in stabilizing VO2(A) and VO2(B) polymorphs, emphasizing the significance of the coexistence of nanodomains at the film–substrate interface in stabilizing specific metastable phases. Additionally, the review article delves into advancements in understanding the phase transition mechanism, adjusting the order parameter in resistivity, and modifying the metal–insulator transition (MIT) temperature through doping. It also summarizes the structural, optical, electronic, and interface properties of these polymorphs and highlights their potential applications in next-generation electronic devices, particularly in the fields of sensing and energy storage. [ABSTRACT FROM AUTHOR]

The intrinsically low electrical conductivity and poor structural fragility of MnO2 have significantly hampered the zinc storage performance. In this work, Ba2+-implanted δ-MnO2 nanosheets have been hydrothermally grown on a carbon cloth (Ba–MnO2@CC) as an extremely stable and efficient cathode material of aqueous zinc-ion batteries. The three-dimensionally porous architecture composed of interwoven thin MnO2 nanosheets effectively shortens the electron/ion transport distances, enlarges the electrode/electrolyte contact area, and increases the active sites for the electrochemical reaction. Meanwhile, Ba2+ could function as an interlayer pillar to stabilize the crystal structure of MnO2. Consequently, the as-optimized Ba–MnO2@CC exhibits remarkable Zn2+ storage capabilities, such as a high capacity (305 mAh g−1 at 0.2 A g−1), prolonged lifespan (95% retention after a 200-cycling test), and superb rate capability. The binder-free cathode is also applicable for flexible energy storage devices with attractive properties. The present investigation provides important insights into designing advanced cathode materials toward wearable electronics. [ABSTRACT FROM AUTHOR]

The effects of the electrical parameters, including storage capacitance, additional inductance, charging voltage, and electrode gap, on the shock wave induced by spark discharge in gas were experimentally investigated. The results showed that the shock waves induced by spark discharge conform to the attenuation law for weak spherical shock waves outside the spark core. The shock wave amplitude is approximately proportional to the electrode gap and storage energy and decreases with increasing inductance. The effect of the charging voltage on the shock wave amplitude can be almost ignored if the storage energy is the same. The average power in the first quarter cycle of spark discharge was found to be closely related to the shock wave amplitude. An empirical equation was given between the shock wave amplitude and the average discharge power, which provides convenient access to set appropriate electrical parameters to generate shock waves of specified amplitude induced by spark discharge. [ABSTRACT FROM AUTHOR]

Aqueous Zn-ion hybrid supercapacitors (AZHSCs) combining the advantages of high‐energy batteries and high‐power supercapacitors see a bright future, but they still suffer from the poor capacity of carbonic cathodes. Herein, a functionalized porous carbon cloth (denoted as FPCC) electrode is demonstrated based on commercial carbon cloth (denoted as CC) tuning by structural and surface engineering. The constructed exfoliated porous carbon layer and the negatively charged functionalized interface not only increase the electrical double layer capacitance but also favor the chemical adsorption of Zn2+ to obtain additional pseudocapacitance. Consequently, the FPCC electrode delivers a high capacity of 0.16 mAh cm−2 at 4 mA cm−2, which is 923.8 times higher than CC, and a long cycle life (85.0% capacity retention after 30 000 cycles). More importantly, the Zn//FPCC AZHSC possesses an impressive energy density (3.3 mWh cm−3) and power density (240 mW cm−3), superior to many advanced batteries and supercapacitors. The quasi-solid-state device is also assembled as a demo. This modification strategy may provide new opportunities for high-performance AZHSCs. [ABSTRACT FROM AUTHOR]

The pursuit of advanced materials to meet the escalating demands of energy storage system has led to the emergence of vertical graphene (VG) as a highly promising candidate. With its remarkable strength, stability, and conductivity, VG has gained significant attention for its potential to revolutionize energy storage technologies. This comprehensive review delves deeply into the synthesis methods, structural modifications, and multifaceted applications of VG in the context of lithium–ion batteries, silicon-based lithium batteries, lithium–sulfur batteries, sodium–ion batteries, potassium–ion batteries, aqueous zinc batteries, and supercapacitors. The review elucidates the intricate growth process of VG and underscores the paramount importance of optimizing process parameters to tailor VG for specific applications. Subsequently, the pivotal role of VG in enhancing the performance of various energy storage and conversion systems is exhaustively discussed. Moreover, it delves into structural improvement, performance tuning, and mechanism analysis of VG composite materials in diverse energy storage systems. In summary, this review provides a comprehensive look at VG synthesis, modification, and its wide range of applications in energy storage. It emphasizes the potential of VG in addressing critical challenges and advancing sustainable, high-performance energy storage devices, providing valuable guidance for the development of future technologies. [ABSTRACT FROM AUTHOR]

The electric grid was designed to move large amounts of energy through space, but decarbonization goals will require it to also move energy through time--from days and seasons with a surplus of energy production to days and seasons with insufficient production. Long-duration energy storage technologies that can hold a large amount of electricity and distribute it over periods of many hours to days and even seasons will play a critical role in the clean energy transition. But creating an environment in which these nascent technologies can develop and thrive will require changes in how the grid is planned and built. [ABSTRACT FROM AUTHOR]

Dielectric energy storage capacitors offer great potential in pulsed power devices due to the high power density and fast charging-discharging rate. Designing a host material with high field-induced polarization is of importance for developing dielectric energy storage materials via further composition modulation. In this paper, we compare the microstructure, dielectric, and ferroelectric properties as well as the energy storage performance of samples K1/2Bi1/2TiO3(KBT), 75KBT-25BiFeO3 (KBTF25), and 88KBT-12Bi0.85Nd0.15FeO3 (KBNTF12) in detail. It is found that, among three samples, sample KBNTF12 possesses the most complex local structure coexisting of a four-distortions with different polarities; meanwhile, sample KBNTF12 behaves as a strong relaxor, thus giving a high field-induced polarization. Besides, sample KBNTF12 realizes the highest electric breakdown strength Eb among three samples, which is resorted to the highest resistivity of grain boundary. Highest ΔP and Eb of sample KBNTF12 among three samples render it achieve ultrahigh stored energy density Ws of 6.94 J/cm3, high recoverable energy density Wr of 5.23 J/cm3, and high efficiency η of 75.4%. Our work suggests that 88KBT-12BNF binary composition be an optimal candidate for dielectric energy storage ceramics. [ABSTRACT FROM AUTHOR]

Rechargeable batteries exhibit poor performance at low temperatures due to sluggish ion transport through the electrolytic phase. Ion transport is governed by three transport parameters—conductivity, diffusion coefficient, and the cation transference number with respect to the solvent velocity—and the thermodynamic factor. Understanding how these parameters change with temperature is necessary for designing improved electrolytes. In this work, we combine electrochemical techniques with electrophoretic NMR to determine the temperature dependence of these parameters for a liquid electrolyte, LiTFSI salt dissolved in tetraglyme between −20 and 45 °C. At colder temperatures, all species in the electrolyte tend to move more slowly due to increasing viscosity, which translates to a monotonic decrease in conductivity and diffusion coefficient with decreasing temperature. Surprisingly, we find that the field-induced velocity of solvent molecules at a particular salt concentration is a nonmonotonic function of temperature. The cation transference number with respect to the solvent velocity thus exhibits a complex dependence on temperature and salt concentration. The measured thermodynamic and transport properties are used to predict concentration gradients that will form in a lithium-lithium symmetric cell under a constant applied potential as a function of temperature using concentrated solution theory. The calculated steady current at −20 °C is lower than that at 45 °C by roughly two orders of magnitude.

Non-aqueous redox flow batteries have shown promise for applications in grid energy storage. Increasing the efficiency of these batteries by developing the electrolyte chemistries is needed. Herein, we investigate the correlation between solvent properties and the electrochemical parameters of vanadium acetylacetonate V(acac)3. Using cyclic voltammetry (CV) and rotating disk electrode experiments (RDE), we show that trends in the performance of the V(acac)3 kinetics are directly related to solvent properties. We found strong relationships between the solvents polarity, viscosity, and donor number with the electrochemical behavior of V(acac)3 in terms of the electrochemical working widow, electron kinetics and stability towards cycling. Based on these finding, we also demonstrate how solvent selection can be improved with limited a priori knowledge.

Poly(3,4‐ethylene dioxythiophene) (PEDOT) is a conducting polymer that can be used in flexible bioelectronic devices. The electrode/electrolyte interface interaction is one of the most important factors in improving the electrochemical performance of energy storage materials, and these polymers are often combined with a negatively charged poly(styrene sulfonate) (PSS) chain to improve their interaction with alkali metal cations such as sodium and potassium. In this work, we performed a one‐step electrochemical synthesis of PEDOT on carbon fabric using the molecule 2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid (AMPS) to create highly effective materials for supercapacitor electrodes. The electrode had a significant increase in capacitance value, measured 16.4 times higher than that of the PEDOT electrode. The 2‐electrode system exhibited a specific capacitance value of 495.2 F g−1 at a scan rate of 5 mV s−1. It exhibited a high operating voltage of 2.3 V in aqueous electrolyte system. It showed a significant energy density of 109.0 Wh kg−1 when operating at 6.1 kW kg−1 power density and 85.2 Wh kg−1 when operating at 30.6 kW kg−1 power density. Recent findings reveal that the capacitance retention performance value of the device increased significantly to 113.9% after 25,000 cycles in 3.0 M NaCl aqueous electrolyte, demonstrating its outstanding long‐term durability. Thus, the creation of the synthesized supercapacitor electrode is a significant advance in the study of conducting polymers, which often have a limited lifetime in real‐world electronic applications. [ABSTRACT FROM AUTHOR]

Antiferroelectric (AFE) materials are potentially useful for energy storage applications. Lead hafnate (PbHfO 3) is one of the prototypical AFE materials. However, its critical field (E cr) which is needed to induce the AFE to ferroelectric phase transition is close to the dielectric breakdown strength. To reduce E cr , we prepare the solid solutions of (1- x)PbHfO 3 – x BiAlO 3 (x = 0.00–0.04) via solid state synthesis. The crystal structures, dielectric behaviour, ferroelectric properties, and energy storage properties are investigated. A temperature-composition phase diagram is established. At room temperature, the crystal symmetry of all compositions is orthorhombic with the Pbam space group. Upon heating, the transition to the AFE orthorhombic Imma phase is observed at the temperature T C1 , which slightly decreases with increasing x , followed by the transition to the cubic phase at the temperature T C2 , which does not depend on x. Distinct dielectric anomalies are observed at T C1 and T C2. It is found that BiAlO 3 substitution reduces E cr and the polarization–electric field relations display characteristic double hysteresis loops. For x = 0.04, at a comparatively small applied field of 130 kV/cm, the values of recoverable energy density (W rec) and efficiency of 0.24 J/cm3 and 84 %, respectively, are obtained. At 190 °C, a W rec = 0.75 J/cm3 and a very high efficiency of 92 % are obtained at the field of 50 kV/cm. Thus, the prepared material can potentially be used in high-temperature pulsed power capacitors for energy storage applications within the temperature range from room temperature up to 190 °C. [ABSTRACT FROM AUTHOR]

The integration of Zn/α-MnO 2 in aqueous zinc-ion batteries (ZIBs) has emerged as a promising avenue owing to their eco-friendliness, facile manufacturability, cost-effectiveness, low flammability, and commendable electrochemical performance. However, the intrinsic limitation in the rate capability of α-MnO 2 constitutes a significant impediment to its practical application. In this study, we introduce K-ion preintercalated nanorods (K-MnO 2 -NR) with a diameter of approximately 10 nm as a cathode material for ZIBs. The synthesis of K-MnO 2 -NR entails a facile one-step electrochemical participation method, whereby K-ion are electrochemically intercalated into the tunnel-structured α-MnO 2. The incorporation of K-ion serves a dual purpose of enhancing the electrical conductivity of manganese oxides and stabilizing the tunnel structure. Consequently, K-MnO 2 -NR manifests exceptional rate capability, exhibiting a specific capacity of 222 mAh g−1 at 2 A g−1, coupled with outstanding cycling stability (with negligible capacity decay observed over 1450 cycles at 2 A g−1). The facile and scalable synthesis process underscores its potential for large-scale production and eventual commercialization in pouch cells for energy storage applications. [ABSTRACT FROM AUTHOR]

In the present work, the investigation of the structural, dielectric, ferroelectric and energy storage properties of polycrystalline samples of (1-x)BaTiO 3 – xEuTiO 3 (BT-ET) solid solution materials prepared by conventional solid-state reaction method has been carried out. X-ray diffraction analyses have revealed the formation of a single-phase tetragonal structure with the P 4 mm space group. Furthermore, the temperature dependence of the dielectric constants marked the presence of the following sequence of structural phase transitions, namely from rhombohedral to orthorhombic, from orthorhombic to tetragonal and from tetragonal to cubic phase transitions with the increase of temperature. A diffuse phase transition has been observed from the dielectric permittivity peak and has been analyzed using the modified Curie-Weiss law and the degree of diffuseness is found to be in the range of 1.16–1.76 due to the existence of different states of polarization. A phase diagram has been established based on the temperature-dependent dielectric permittivity studies. The room temperature ferroelectric properties point to a coercive field larger than that of BaTiO 3 ceramics. Broad dielectric peaks associated with diffuse phase transition appear in a wide temperature range (40–100 °C) with the highest dielectric permittivity ε' = 6498 found in the x = 0.05 ceramics. Moreover, an improved energy storage performance is obtained in the 0.95BaTiO 3 -0.05EuTiO 3 ceramic with a recoverable energy density of W rec = 0.797 J/cm3, coupled with an efficiency η = 73 % at 170 kV/cm and the highest storage energy density of W st = 1.571 J/cm3 is obtained for 0.90BaTiO 3 -0.10EuTiO 3 , which is superior to other lead-free BT-based ceramics. All these features demonstrate that the BT-ET ceramics can be widely used in energy storage applications and also in high-temperature multilayer capacitors for automotive, aerospace and related industries. [ABSTRACT FROM AUTHOR]

Environment-friendly piezoelectric micro/nanogenerators have attracted tremendous attention due to the increasing demand for portable self-power devices. Here, the [(0.94−x)Bi 0.5 Na 0.5 TiO 3 –0.06BaTiO 3 –xK 0.5 Na 0.5 NbO 3 ; BNT-BT-xKNN] lead-free ceramic, at x = 0, 0.02, 0.04, 0.06, 0.08 and 0.10 mol%, was prepared via the solid-state method. The doping concentration x = 0.02 mol% shows the highest dielectric properties and the lowest dielectric loss. The active layer of the hybrid device is made by mixing BNT-BT-2KNN into the PDMS to form a series of polymer-ceramic composite films ranging from 7 to 19 wt% of BNT-BT-2KNN. The electrical response of the composite film is systematically studied with the addition of different weight percentages of the particles to the PDMS matrix. It was found that incorporating BNT-BT-2KNN at 11 wt% into the PDMS matrix exhibited the optimum harvesting performance, resulting in an output voltage and current density of about 30 V and 0.28 μA/cm2, respectively. The hybridized PENG and TENG devices could operate in a long-term cyclic mode, charge the capacitor for energy storage, and also light up LEDs. This research proposed a simple device fabrication and provided a guideline for the development of high-performance microgenerators, which is crucial for device development and practical use in the future. [ABSTRACT FROM AUTHOR]

Ferroelectric ceramic capacitors have potential advantages in energy storage performance, such as high energy storage density and fast discharge speed, making them widely applicable in different energy storage devices. During heat treatment, ferroelectric ceramics undergo an evolution of grain growth leading to changes in dielectric properties. Optimizing the energy storage properties of ferroelectric ceramics during heat treatment is a crucial issue. In this work, a phase field modeling for dielectric breakdown coupled with a grain growth model is developed to give a fundamental understanding of the effect of grain growth on dielectric breakdown. In addition, this work proposes a breakdown detection method to shorten the computational time of the model. The results indicate the existence of a local maximum of the breakdown field strength during grain growth, leading to a local maximum of the energy storage density. It is found that the dielectric breakdown strength and the pattern of the final breakdown path are significantly influenced by the grain size and distribution. The model is also applicable to various dielectrics and provides guidance for the design of high-energy storage dielectrics. [ABSTRACT FROM AUTHOR]

In this study, the influence of La3+ substitution on the phase structure, microstructure, electrical and energy storage properties of (Sr 0.3 Bi 0.35 Na 0.335 Li 0.015) 1-x La x TiO 3 (SBNLT-xLa) ceramics with x = 0–0.05, using the solid-state combustion technique, was investigated. X-ray diffraction (XRD) patterns indicated a pure perovskite structure formed, along with coexisting rhombohedral and tetragonal phases in all ceramics. The Rietveld refinement analysis showed the tetragonal phase increased while the rhombohedral phase decreased with increased La3+ content. The morphology of the SBNLT-xLa ceramics displayed polygonal grain shapes and anisotropic grain growth. Average grain sizes increased from 2.01 to 2.43 μm as x increased from 0 to 0.01 and afterwards decreased as x increased further. Both the measured density and maximum dielectric constant (ɛ m) decreased from 5.48 to 5.29 g/cm3 and from 4667 to 2313, respectively, when x increased from 0 to 0.05. A decrease in the dielectric properties caused by the phase ratio shifting away from a morphotropic phase boundary (MPB) condition, poor microstructure and low density was produced with La3+ replacement. The maximum polarization (P max), remnant polarization (P r) and coercive field (E c) decreased with increased La3+ content. A decline in P r and E c improved the energy storage efficiency (ƞ) and energy storage loss (W loss), resulting in enhanced energy storage properties. At x = 0.02, the ceramic showed good energy storage properties (W total of 0.781 J/cm3, W rec of 0.624 J/cm3, W loss of 0.157 J/cm3 and ƞ of 79.8%), measured at 60 kV/cm. [ABSTRACT FROM AUTHOR]

The development of lead-free dielectric capacitors with high recoverable energy storage density and high energy storage efficiency is important for improving the overall performance of electronic and power systems. BaTiO 3 (BTO) is one of the most common ferroelectric materials and has attracted much attention for energy storage applications in the past decades due to its excellent dielectric and ferroelectric properties. However, high remnant polarization and low electrical breakdown strength of BTO limit its development in energy storage applications. Many efforts (e.g., elements doping, interface/heterostructure, etc.) have been made to improve the energy storage density of BTO thin films. In this paper, Ba 1-x Ni x TiO 3 thin films (x = 0, 0.02, 0.04, 0.06, 0.08; abbreviated as BN x T) were synthesized via sol-gel and spin-coated method. The effect of Ni doping on the structural, dielectric, ferroelectric and energy storage properties of BTO thin films has been studied. The results confirmed that with the increase of Ni doping, a second phase arises and the dielectric constant decreases. While appropriate Ni doping led to the improvement of the breakdown strength, further increase of Ni deteriorated the energy storage because of the high oxygen vacancy. Finally, optimized energy storage performance was obtained for BN 0.04 T thin film: dielectric constant of 401, dielectric loss of 0.002, recoverable energy density of 20.2 J/cm3 and energy storage efficiency of 83.6% at 965 kV/cm. Meanwhile, the remnant and maximum polarization of the films were 0.06 μC/cm2 and 50 μC/cm2, respectively. BN 0.04 T thin film has an excellent application prospect and is expected to appear as a component in the future composite energy storage film system. [ABSTRACT FROM AUTHOR]

With the continuous development of society, the energy demand is also increasing, and the consumption of fossil fuels is becoming more and more serious. Dielectric capacitors are widely used in electronic devices due to their advantages of fast charging and discharging speed and high power density. In this work, 2D-Na 0.5 Bi 0.5 TiO 3 (2D-NBT) filler and polyimide (PI) polymer matrix were compounded to prepare 2D-NBT/PI composites, and the energy storage performance of the composites was improved by surface modification of the filler and the design of 'sandwich' structure. The prepared samples were analyzed by XRD, SEM and dielectric properties. For 2D-NBT/PI single-layer composites, when the volume fraction of NBT powder is 0.25 vol.%, the energy storage density of the composites reaches 11.11 J/cm3 under the electric field of 400 kV/mm. For the 'sandwich' structure 2D-NBT/PI composites, when the system of 2D-NBT/PI composites is 0.25-0-0.25, the energy storage density of the composites reaches 12.44 J/cm3 under the electric field of 440 kV/mm. [ABSTRACT FROM AUTHOR]

Lead-free ferroelectric ceramics with a composition of 0.7(Bi 0.5 Na 0.5) 0.7 Sr 0.3 Ti (1- x) O 3 -0.3Ba 0.94 La 0.04 (Mg 1/3 Nb 2/3) x O 3 (abbreviated as 0.7BNST (1- x) -0.3BL(MN) x , 0 ≤ x ≤ 0.12) were prepared using solid-phase sintering method, involving co-substituting at A and B sites. High recoverable energy density (W rec) of 3.54 J/cm3 and energy efficiency (η) 85.49% are achieved at an electric field of 270 kV/cm. Furthermore, these ceramics exhibited excellent temperature and cycle stability at 120 kV/cm (within 25 °C–150 °C, W rec fluctuation range <14 %; under 1∼106 cycles, the W rec fluctuation range <5 %). In terms of dielectric performance, they exhibited a high dielectric constant (ε r ∼4540), an extremely low dielectric loss tanδ of <0.04 (30 °C–300 °C), and good temperature stability with Δ ε / ε 150 °C ≤ ±15 % (−19.5 °C–233.4 °C). During the charging and discharging process, these ceramics demonstrated a high energy density (W d) of 1.2 J/cm3, a power density (P D) of 61.7 MW/cm3, and an extremely short discharge time (t 0.9) of approximately ∼0.11 μs. This study has improved the dielectric energy storage performance of BNT-based lead-free piezoelectric ceramics, making them suitable for use in pulse power devices. [ABSTRACT FROM AUTHOR]

The design of fault-tolerant structures against the breakdown of heterogeneous ferroelectric films is essential to enhance the breakdown strength. Based on the self-repairing theory, heterogeneous ferroelectric PbZr 0.52 Ti 0.48 O 3 (PZT) film capacitors with a fault-tolerant structures against breakdown were synthesized by utilizing dielectric/electrolytic dual characteristics of the amorphous aluminum oxide film (AmAO). The PZT/AmAO composite films with Au top electrodes exhibited significant weak breakdown at low voltages, whereas the breakdown in the composite films with Al top electrodes have been repaired and no longer occurred. Compared to PZT(100 nm)/AmAO(120 nm) composite films with Au top electrodes, breakdown strength of PZT(100 nm)/AmAO(120 nm) composite films with Al top electrodes improves from 278 MV/m to 477 MV/m, energy storage density increased from 14.3 J/cm3 to 22.5 J/cm3, since the heterogeneous interface and structural defects have been repaired by adaptive anodizing of Al electrode under high electric field. Cross-sectional SEM images have confirmed the formation of fresh aluminium oxide films (AAO) at the interfaces of AmAO/Al and PZT/AmAO during the application of an electric field. Defects have been effectively repaired, resulting in an increase in breakdown strength. This study establishes a theoretical and technical foundation for the design of fault-tolerant structures against breakdown in heterogeneous ferroelectric films. [ABSTRACT FROM AUTHOR]

High entropy oxides with interesting physical properties can be obtained by the design of A-site cations. Herein, a series of medium entropy and high entropy perovskite ceramics (Ba 0.25 Sr 0.25 Ca 0.25 Bi 0.25)TiO 3 , (Ba 0.2 Sr 0.2 Ca 0.2 Bi 0.2 La 0.2)TiO 3 , (Ba 0.2 Sr 0.2 Ca 0.2 Bi 0.2 Na 0.2)TiO 3 and (Ba 0.2 Sr 0.2 Ca 0.2 La 0.2 Na 0.2)TiO 3 were synthesized by the solid-state method, which selected various valence elements to achieve a single-phase structure and increase the lattice distortion. The microstructure indicated that the high-entropy ceramics exhibited the same macroscopic single perovskite while the local configuration is different. Mesoscopic results show that high entropy can adjust the polarization and relaxation of ferroelectrics, so as to optimize the energy storage performance. Meanwhile, the results manifest that grain boundaries, oxygen defects and relaxation can be changed by entropy configuration. Our work proves that the properties of high entropy ferroelectric materials can be regulated by different valence states of the elements in high entropy and explores the relevant mechanism, which provides a possible opportunity for the design and application of high-entropy dielectric materials with excellent properties. [ABSTRACT FROM AUTHOR]

In this study BNBCTS ceramics were co-doped with Fe and Sb to form (Bi 0.5 Na 0.5) 0.93 (Ba 0.945 Ca 0.055) 0.07 (Ti (0.9946-x) Sn 0.0054)(Fe 0.5 Sb 0.5) x O 3 ceramics (denoted as BNBCTS-xFS) with various x content and were prepared via the solid-state combustion technique to enhance the electrical and energy storage performance. The effect of co-doping Fe and Sb on the phase formation, defect dipole, microstructure, electrical and energy storage properties of BNBCTS-xFS ceramics was studied. When x content increased from 0.0 to 0.030, the amount of the rhombohedral (R) phase decreased from 51 to 24 % while the tetragonal (T) phase increased from 49 to 76 %. The increased Fe and Sb content increased the defect dipole of singly/doubly charged oxygen-vacancies (V O ∙ / V O ∙ ∙ ) and caused more Ti4+ to transition to Ti3+, which caused the transition temperature of the ferroelectric phase to relaxor state (T F-R) in the ceramics to drop to below room temperature and it exhibited relaxor characteristics at room temperature. The ceramic with an x content of 0.010 had the largest grain size (3.06 μm), excellence ferroelectric properties (P r ∼31.04 μC/cm2, P m ∼38.98 μC/cm2 and E c ∼18.28 kV/cm), the largest electro strain (∼0.175 %) and a large d 33 * of 350 pm/V. Moreover, when x = 0.020, the ergodic relaxor ceramic showed the smallest grain size (1.03 μm), the lowest remanant polarization (P r) of 4.52 μC/cm2 and the lowest coercive field (E c) of 8.37 kV/cm, at an electric field of 60 kV/cm. More importantly, energy storage properties at the electric breakdown strength (E b = 120 kV/cm) of the ceramics with an x content of 0.020 exhibited a recoverable energy storage density (W rec) of 1.81 J/cm3, a total energy storage density (W total) of 2.95 J/cm3 and an efficiency (η) of 61.30%, with excellent thermal (∼25–150 °C) and frequency stability (∼1–100 Hz). This study provides new insights into the modulation of BNBCTS ceramics with Fe and Sb co-doping, which could effectively improve the electrical properties and energy storage properties of BNBCTS-xFS ceramics. [ABSTRACT FROM AUTHOR]