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[Display omitted] Three-dimensional interconnected nickel–cobalt layered double hydroxides (NiCo-LDHs) were prepared on nickel foam by ion exchange using a cobalt-based metal–organic framework (Co-MOF) as a template at different temperatures. The effects of the Co-MOF preparation temperature on the growth, mass, morphology, and electrochemical properties of the Co-MOF and derived NiCo-LDH samples were studied. The synthesis temperature from 30 to 50 °C gradually increased the mass of the active material and the thickness of the Co-MOF sheets grown on the nickel foam. The higher the temperature is, the larger the proportion of Co3+. β-Cobalt hydroxide (β-Co(OH) 2) sheets were generated above 60 °C. The morphology and mass loading pattern of the derived flocculent layer clusters of NiCo-LDH were inherited from metal-organic frameworks (MOFs). The areal capacitance of NiCo-LDH shows an inverted U-shaped curve trend with increasing temperature. The electrode material synthesized at 50 °C had a tremendous specific capacitance of 7631 mF·cm−2 at a current density of 2 mA·cm−2. The asymmetric supercapacitor assembled with the sample and active carbon (AC) achieved an energy density of 55.0 Wh·kg−1 at a power density of 800.0 W·kg−1, demonstrating the great potential of the NiCo-LDH material for energy storage. This work presents a new strategy for designing and fabricating advanced green supercapacitor materials with large power and energy densities. [ABSTRACT FROM AUTHOR]

Benefitting from the synergetic effects of heterostructured sulfide as the charge transfer accelerator and N -doped carbon matrix as an armor, the bimetallic FeS 2 /MoS 2 heterostructure confined in nitrogen-doped carbon (FMS@NC) delivers a comprehensive K-ions storage ability. Moreover, the as-built K-ion capacitor based on FMS@NC anode and activated carbon cathode achieves a high energy/power density as well as ultra-long cycling stability. [Display omitted] The means of structural hybridization such as heterojunction construction and carbon-coating engineering for facilitating charge transfer and electron transport are considered viable strategies to address the challenges associated with the low rate capability and poor cycling stability of sulfide-based anodes in potassium-ion batteries (PIBs). Motivated by these concepts, we have successfully prepared a hydrangea-like bimetallic sulfide heterostructure encapsulated in nitrogen-doped carbon (FMS@NC) using a simple solvothermal method, followed by poly-dopamine wrapping and a one-step sulfidation/carbonization process. When served as an anode for PIBs, this FMS@NC demonstrates a high specific capacity (585 mAh g−1 at 0.05 A/g) and long cycling stability. Synergetic effects of mitigated volume expansions and enhanced conductivity that are responsbile for such high performance have been verified to originate from the heterostructured sulfides and the N -doped carbon matrix. Meanwhile, comprehensive characterization reveals existence of an intercalation-conversion hybrid K-ion storage mechanism in this material. Impressively, a K-ion capacitor with the FMS@NC anode and a commercial activated carbon cathode exhibits a superior energy density of up to 192 Wh kg−1, a high power density, and outstanding cycling stability. This study provides constructive guidance for designing high-performance and durable potassium-ion storage anodes for next-generation energy storage devices. [ABSTRACT FROM AUTHOR]

A high performance lamellar structured Fe-doped MnS/graphene anode has been developed for sodium-ion storage. Due to the synergistic positive effect of graphene confinement, strong Mn S C bonding and Fe-doping, the composite exhibits excellent rate performance and long-term stability. A prototype sodium-ion capacitor fabricated with Fe-MnS/PG anode and nitrogen-doped carbon cathode can deliver both high energy and high power densities. [Display omitted] Manganese sulfide (MnS) is a promising converion-type anode for sodium storage, owing to the virtues of high theoretical capacity, coupled with it crustal abundance and cost-effectiveness. Nevertheless, MnS suffers from inadequate electronic conductivity, sluggish Na+ reaction kinetics and considerable volume variation during discharge/charge process, thereby impeding its rate capability and capacity retention. Herein, a novel lamellar heterostructured composite of Fe-doped MnS nanoparticles/positively charged reduced graphene oxide (Fe-MnS/PG) was synthesized to overcome these issues. The Fe-doping can accelerate the ion/electron transfer, endowing fast electrochemical kinetics of MnS. Meanwhile, the graphene space confinement with strong Mn S C bond interactions can facilite the interfacial electron transfer, hamper volume expansion and aggregation of MnS nanoparticles, stabilizing the structural integrity, thus improving the Na+ storage reversibility and cyclic stability. Combining the synergistic effect of Fe-doping and space confinement with strong Mn S C bond interactions, the as-produced Fe-MnS/PG anode presents a remarkable capacity of 567 mAh/g at 0.1 A/g and outstanding rate performance (192 mAh/g at 10 A/g). Meanwhile, the as-assembled sodium-ion capacitor (SIC) can yield a high energy density of 119 Wh kg−1 and a maximum power density of 17500 W kg−1, with capacity retention of 77 % at 1 A/g after 5000 cycles. This work offers a promising strategy to develop MnS-based practical SICs with high energy and long lifespan, and paves the way for fabricating advanced anode materials. [ABSTRACT FROM AUTHOR]

[Display omitted] The imbalances of storage capacity and reaction kinetics between carbonaceous cathodes and zinc (Zn) anodes restrict the widespread application of Zn-ion hybrid capacitor (ZIHC). Structure optimization is a promising strategy for carbon materials to achieve sufficient Zn2+ storage sites and satisfied ion–electron kinetics. Herein, porous graphitic carbon nanosheets (PGCN) were simply synthesized using a K 3 [Fe(C 2 O 4) 3 ]- and urea-assisted foaming strategy with polyvinylpyrrolidone as carbon precursor, followed by activation and graphitization. Sufficient pores with well-matched pore sizes (0.80–1.94 nm) distributed across the carbon nanosheets can effectively shorten mass-transfer distance, promoting accessibility to active sites. A partially graphitic carbon structure with high graphitization degree can accelerate electron transfer. Furthermore, high nitrogen doping (7.2 at.%) provides additional Zn2+ storage sites to increase storage capacity. Consequently, a PGCN-based ZIHC has an exceptional specific capacity of 181 mAh g−1 at 0.5 A g−1, superb energy density of 145 Wh kg−1, and excellent cycling ability without capacity decay over 10,000 cycles. In addition, the flexible solid-state device assembled with PGCN exhibits excellent electrochemical performances even when bent at various angles. This study proposes a straightforward and economical strategy to construct porous graphitic carbon nanosheets with enhanced storage capacity and fast reaction kinetics for the high performance of ZIHC. [ABSTRACT FROM AUTHOR]

A newly designed third-order mixed-mode orthogonally tuned quadrature oscillator, generating sinusoidal voltage and current waveforms, is introduced in this paper. The reported circuit is realized using two dual-X current conveyor transconductance amplifiers (DXCCTAs), two active MOS-based grounded resistors and three grounded capacitors. MOS-C realization of the proposed oscillator with all grounded capacitors is the best choice for modern integration. In this study, the ideal and non-ideal analyses and frequency stability aspect of the circuit are elucidated. The proposed third-order oscillator circuit has the advantages of orthogonally controllable frequency of oscillation & condition of oscillation, very good operating frequency (34.25 MHz) and low total harmonic distortion (within 1.8%). The theoretical analyses have been validated by both pre-layout and post-layout simulations using general process design kit 0.18 μ m technology and the results have been compared with relevant state-of-the-art works. Layout of the used active block, DXCCTA, is developed with Cadence Virtuoso that measures an area of 38 μ m × 2 1 μ m. [ABSTRACT FROM AUTHOR]

The relationship between the dielectric constant and leakage current of materials often exhibits a negative correlation. However, to sustain Moore's Law, the semiconductor industry necessitates novel materials that simultaneously possess a high dielectric constant and low leakage current, meeting the shrinking demands of electronic components. In this study, a high-performance hafnium-based thin film capacitor achieved through the collaborative effects of bottom electrode engineering and ion doping. Tungsten (W) as the bottom electrode, with its chemically inert nature and low thermal expansion coefficient, proves advantageous in improving interface quality and promoting the generation of the high- k phase in HfO 2. Concurrently, yttrium (Y) ion doping contributes to stabilizing the high- k phase of HfO 2 , reducing non-lattice oxygen, and enhancing the disorderliness of the dielectric thin film. By synergistically integrating these factors, the hafnium-based thin film capacitor achieves a high dielectric constant of 36.6 while maintaining minimal leakage current (Electric field ∼ 6 MV/cm, J ∼ 10−8 A/cm2) and a high charge storage capacity (U rec ∼ 104.4 J/cm³). These research findings open a promising pathway for the development of novel hafnium-based materials with broad applicability and exceptional dielectric performance. [ABSTRACT FROM AUTHOR]

[Display omitted] Lithium-ion batteries (LIBs) and electrical double-layer capacitors (EDLCs) are widely used in commercial energy storage systems, but each has inherent limitations. To overcome these limitations, the lithium-ion capacitor (LIC) has emerged as a hybrid energy storage device, combining the benefits of LIBs and EDLCs. However, the introduction of active lithium into LICs poses challenges due to lithium's reactivity and instability. In this study, we propose a dual wet chemical prelithiation strategy to enhance LIC performance. By wet chemically prelithiating both the activated carbon cathodes and hard carbon anodes, significant improvements are achieved compared to traditional prelithiation methods. The dual prelithiation approach outperforms electrochemical prelithiation in terms of energy storage performance, cycle life, and process simplification. LICs with dual wet chemically prelithiated electrodes demonstrate the highest energy density and retain a substantial portion of reversible capacity even at high discharge rates. The strategy exhibits fast kinetics and wide operational stability. In contrast, LICs with metallic lithium anodes or electrochemically prelithiated hard carbon anodes exhibit inferior performance and limited cycle life. The dual wet chemical prelithiation strategy represents a breakthrough in LIC technology, offering superior performance, cycle stability, and scalability. It holds promise for alkali-ion energy storage systems and drives advancements in electrochemical energy storage technology. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous ammonium-ion capacitors (AAICs) are promising for large-scale energy storage owing to low cost and inherent safety, while their practical applications are suffered from performance under extreme environment. Low ion conductivity and high viscosity, as well as freezing of the electrolyte, are the main issues for the electrochemical performance failure at low temperatures. In this work, the AAICs were assembled with commercial carbon electrodes and antifreeze electrolyte, where the electrolyte with a freezing point lower than −115 °C is developed by using Ethylenediamine (EDA) as an additive with a volume ratio of 50 % to an aqueous solution of 0.5 M NH 4 Cl. This antifreeze electrolyte displays a superior ionic conductivity of 8.58 mS cm−1 and a weaker viscosity of 8.16 mPa s at low temperatures. Furthermore, the spectroscopic investigations and molecular dynamics (MD) simulations demonstrate that the addition of EDA can break the hydrogen bonds of water molecules and modulate the solvation structure. Therefore, the assembled AAICs with electrolytes of 0.5 M NH 4 Cl (50 %-EDA) could be operated at wide-temperature conditions steadily, exhibiting excellent capacity, rate performance and good cycling stability. This work provides a simple and effective strategy for wide-temperature energy storage devices. [ABSTRACT FROM AUTHOR]

The two-dimensional layered Ti 3 C 2 T x and N-doped Carbon Nanotube Hollow Polyhedron were tightly anchored together by strong electrostatic adsorption, which ensures the complexity of the multilevel structure and high electronic conductivity and fast transport channels. [Display omitted] • N-doped carbon nanotube hollow polyhedron/Ti 3 C 2 T x prepared with hierarchical multilevel structures. • Electrochemical performance enhancement due to rational heat treatment temperature and "electron sharing" mechanism. • Co 3 O 4 -CNT-800/Ti 3 C 2 T x provides exceptional lithium storage properties with a stabilized structure. The matching of long cycle life, high power density, and high energy density has been an inevitable requirement for the development of efficient anode materials for lithium-ion capacitors (LICs). Here, we introduce an N -doped carbon nanotube hollow polyhedron structure (Co 3 O 4 -CNT-800) with high specific surface area and active sites, which is anchored with two-dimensional (2D) Ti 3 C 2 T x nanosheets with metallic conductivity and abundant surface functional groups by electrostatic adsorption to form a hierarchical multilevel hollow semi-covered framework structure. Benefiting from the synergistic effect between Co 3 O 4 -CNT-800 and Ti 3 C 2 T x , the composites exhibit superior energy storage efficiency and long cycling stability. The Co 3 O 4 -CNT-800/Ti 3 C 2 T x electrodes exhibit a high specific capacity of 817C/g at a current density of 0.5 A/g under the three-electrode system, and the capacity retention rate is 91 % after 5000 cycles at a current density of 2 A/g. Additionally, we assembled Co 3 O 4 -CNT-800/Ti 3 C 2 T x as the anode and Activated carbon (AC) cathode to form LIC devices, which showed an electrochemical test result of 90.01 % capacitance retention after 8000 cycles at 2 A/g, and the maximum power density of the LIC was 3000 W/kg and the maximum energy density was 121 Wh/kg. This work pioneered the combination of N -doped carbon nanotube hollow polyhedron structure with two-dimensional Ti 3 C 2 T x , which provides an effective strategy for preparing LIC negative electrode materials with high specific capacitance and long cycling stability. [ABSTRACT FROM AUTHOR]

In the present study, an analytical model is developed to investigate the dehydration efficiency of a NATCO Dual Polarity® electrostatic treater at steady state conditions using population balance equations (PBE). To investigate the effect of frequency on dehydration performance and electric field strength between electrodes, a detailed electrical model is considered. In the developed electrical model, electrodes are virtualized as simple ideal capacitors, with emulsion acting as dielectric. Proving the model's accuracy, gathered industrial data were compared with simulation results. In addition, current frequency as the main electrical parameter besides power supply electrical potential was proved to be effective on the strength of the applied electric field, the electrical potential profile on electrodes, and the outlet water cut in the treated crude oil. The results indicated that increasing the current frequency from 50 to 500 Hz, by enhancing direct current field strength, reduces the water cut by 0.03%. Although high temperatures and frequencies increase the electrical conductivity of the emulsion, electrical power lost during the disconnection of the power supply on electrodes will be retrieved by increasing frequency. Finally, the performance of different electric fields on crude oil dehydration was compared. [ABSTRACT FROM AUTHOR]

A capacitance multiplier is an active circuit designed specifically to increase the capacitance of a passive capacitor to a significantly higher capacitance level. In this paper, the use of a voltage differencing differential difference amplifier (VDDDA), an electronically controllable active device for designing grounded and floating capacitance multipliers, is proposed. The capacitance multipliers proposed in this study are extremely simple and consist of a VDDDA, a resistor, and a capacitor. The multiplication factor ( K c ) can be electronically controlled by adjusting the external bias current ( I B ). It offers an easy way of controlling it by utilizing a microcontroller for modern analog signal processing systems. The multiplication factor has the potential to be adjusted to a value that is either less than or greater than one, hence widening the variety of uses. The grounded capacitance multiplier can be easily transformed into a floating one by utilizing Zc-VDDDA. PSpice simulation and experimentation with a VDDDA realized from commercially available integrated circuits were used to test the performance of the proposed capacitance multipliers. The multiplication factor is electronically adjustable, ranging in approximation from 0.56 to 13.94. The operating frequency range is approximately three frequency decades. The realization of the lagging and leading phase shifters using the proposed capacitance multiplier is also examined and proven. The results reveal that the lagging and leading phase shifts are electronically tuned via the multiplication factor of the proposed capacitance multipliers. [ABSTRACT FROM AUTHOR]

Materials offering high energy density are currently desired to meet the increasing demand for energy storage applications, such as pulsed power devices, electric vehicles, high-frequency inverters, and so on. Particularly, ceramic-based dielectric materials have received significant attention for energy storage capacitor applications due to their outstanding properties of high power density, fast charge–discharge capabilities, and excellent temperature stability relative to batteries, electrochemical capacitors, and dielectric polymers. In this paper, we present fundamental concepts for energy storage in dielectrics, key parameters, and influence factors to enhance the energy storage performance, and we also summarize the recent progress of dielectrics, such as bulk ceramics (linear dielectrics, ferroelectrics, relaxor ferroelectrics, and anti-ferroelectrics), ceramic films, and multilayer ceramic capacitors. In addition, various strategies, such as chemical modification, grain refinement/microstructure, defect engineering, phase, local structure, domain evolution, layer thickness, stability, and electrical homogeneity, are focused on the structure–property relationship on the multiscale, which has been thoroughly addressed. Moreover, this review addresses the challenges and opportunities for future dielectric materials in energy storage capacitor applications. Overall, this review provides readers with a deeper understanding of the chemical composition, physical properties, and energy storage performance in this field of energy storage ceramic materials. [ABSTRACT FROM AUTHOR]

The health management of railway signal equipment in the high-speed railway is a key link between intelligent operation and maintenance. Accurately predicting the health state of compensation capacitors is of great significance to ensure the reliable work of track circuits. This paper proposes an improved deep neural network algorithm focusing on the problem of long-term accurate health forecasts for compensation capacitors. First, establishing a transmission state model for degradation mechanism mining, the difference function that can quantitatively evaluate features is defined by piecewise processing cab signaling receiving voltage. Introducing the degradation model, predictive driving under both model and data is implemented. Then, the convolutional neural networks and bidirectional long–short-term memory are combined and improved to construct a novel artificial intelligence combination strategy, while parameters are optimized based on the sparrow search algorithm. Finally, facing the conditional repair of compensation capacitors, we set a reasonable threshold for the occurrence of hidden dangers to complete fault warning. This novel and practical approach effectively explores the procedure of prognosis and health management, while the refined maintenance will better utilize current monitoring information, helping the intelligence and accuracy of safety control decision-making. [ABSTRACT FROM AUTHOR]

To address the alerting issue of energy demand, lithium-ion capacitors (LICs) have been widely studied as promising electrochemical energy storage devices, which can deliver higher energy density than supercapacitors (SCs), and have higher power density with longer cycling life than lithium-ion batteries (LIBs). In this work, the active material lithium nickel cobalt manganese oxide LiNi0.5Co0.2Mn0.3O2 (NCM523) is grown on a cotton textile template and building a 3-dimensional (3D) integrity to improve capacitance and energy density of LICs by enhancing the interfacial ion-exchange process. With the 3D structure, the specific discharge capacitance is increased to 718.67 F g-1 at 0.1 Ag-1 from that of non-textile NCM523 (265.97 F g-1), and remains a high capacitance of 254.48 Fg-1 at 10 Ag-1 in the half-cell capacitors. In addition, the energy density can achieve up to 36.17 Whkg-1 at the power density of 1,200 Wkg-1 in the full-cell capacitor. The textile NCM can maintain an energy density of 28.26 Whkg-1 at the current density of 10 Ag-1 and power density of 6,000Wkg-1. Our results present promising applications of electrodes with the 3D porous structure for high energy density LICs. [ABSTRACT FROM AUTHOR]

A mathematical model is presented for the optimisation of an Electromagnetic Halbach Array (EHA) for wireless power transfer. The mathematical model is based on Biot‐Savart's law of magnetic field in a current‐carrying square loop. The model is validated through static electromagnetic simulations in ANSYS Maxwell and found to be accurate and effective when predicting the magnetic field within the EHA box. To verify the analytical and simulation results, an EHA was fabricated, and experimental verification was carried out. The results show that the mathematical model can be widely used in the analysis and design optimisation of EHAs of any size and with diverse parameters in the case of single‐layer square spiral planar coils. [ABSTRACT FROM AUTHOR]

[Display omitted] Lithium ion capacitors (LICs) are a new generation of energy storage devices that combine the super energy storage capability of lithium ion batteries with the satisfactory power density of supercapacitors. The development of high-performance LICs still faces great challenges due to the unbalanced reaction kinetics at the anode and cathode. Therefore, it is an inevitable need to enhance the electron/ion transfer capability of the anode materials. In this paper, to obtain a superior-rate and high-capacity Ni 3 S 2 -based anode, highly conductive Ti 3 C 2 T x MXene sheets were introduced to sever as the carrier of Ni 3 S 2 nanoparticles and simultaneously an amorphous carbon layer which coats onto the surface of Ni 3 S 2 nanoparticles was in-situ generated by the carbonization of dopamine reactant. The as-synthesized Ni 3 S 2 /Ti 3 C 2 T x /C composite exhibits a high specific surface area (112.6 m2/g) because of the addition of Ti 3 C 2 T x that can reduce the aggregation of Ni 3 S 2 nanoparticles and the in-situ generated amorphous carbon layer that can suppress the growth of Ni 3 S 2 nanoparticles. The Ni 3 S 2 /Ti 3 C 2 T x /C anode possesses a remarkable reversible discharge specific capacity (626.0 mAh/g under 0.2 A/g current density), which increases to 1150.8 mAh/g after 400-cycle charge/discharge measurement at the same measurement condition indicating eminent cyclability, along with superior rate capability. To construct a superior-performance LIC device, a sterculiae lychnophorae derived porous carbon (SLPC) cathode with an average discharge specific capacity of 73.4 mAh/g@0.1A/g was prepared. The Ni 3 S 2 /Ti 3 C 2 T x /C//SLPC LIC device with optimal cathode/anode mass ratio has a satisfactory energy density ranging from 32.8 to 119.1 Wh kg−1 at the corresponding power density of 8799.4 to 157.5 W kg−1, together with a prominent capacity retention (95.5 %@1 A/g after 10,000 cycles). [ABSTRACT FROM AUTHOR]

In this work, polycrystalline n-CrSe2 nanosheets with thickness of 100 nm are grown on p-type Si wafers by the thermal deposition technique under vacuum pressure of 10−5 mbar. Structural and optical investigations showed the preferred growth of the trigonal phase of CrSe2 on Si substrates. Direct allowed transitions within an energy band gap of 2.60 eV were found to be dominant in the films. Silver contacts on the layers allowed construction of hybrid optoelectronic device structure formed from Ag/p-Si Schottky arm and p -Si/ n -CrSe2 pn junction. The device runs in such a way that forward biasing of the Schottky arm is accompanied by a reverse biasing of the pn junction. It is observed that the hybrid device structure can perform as a high-frequency capacitor. The capacitance–voltage characteristic curves show that these capacitors can respond to ac signals with frequencies of 100 MHz. They also exhibit bandstop filter characteristics allowing the passing of signals with return loss and voltage standing wave ratios exceeding 10 dB and 1.76, respectively, at 60 MHz. The device under study displayed rectifying and photo-sensing properties with an asymmetry ratio of 60 in the dark and 217 under excitation of visible light. Visible light excitation of these photosensors displayed voltage biasing dependence in their current responsivity, external quantum efficiency and specific detectivity, reaching values of 0.24 A/W, 65.2% and 4.83 × 109 Jones, respectively. The features of the hybrid devices which use CrSe2 nanosheets as active media make them good candidates for use in radio wave and visible light communication technologies. [ABSTRACT FROM AUTHOR]

Reactive power compensation (RPC) is a big problem during power system operation. Parenthetically, capacitor allocation and sizing may be the only convenient solution for RPC of power systems. The loss sensitivity factor (LSF) is applied here for finding the optimum capacitor position. This paper presents quasi-oppositional fast convergence evolutionary programming (QOFCEP), fast convergence evolutionary programming (FCEP), and evolutionary programming (EP) for the optimum location and sizing of shunt capacitors in the isolated microgrid (MG) for minimizing total real power loss throughout the day with and without the demand response program (DRP). The 33-node, 69-node, and 118- node isolated MGs have been studied to authenticate the efficacy of the suggested approach. Each MG includes small hydro power plants (SHPPs), solar PV plants (SPVPs), wind turbine generators (WTGs), diesel generators (DGs), and plug-in electric vehicles (PEVs). [ABSTRACT FROM AUTHOR]

Background: With the increasingly serious environmental pollution and natural environment damage, renewable energy such as solar cells have gradually become the key to change this situation. Therefore, the local abnormal diagnosis of the charge and discharge of solar cell capacitors is particularly important. Objective: To extend the life of ultracapacitors by resolving the issue of their low detection rate and enhancing the capacity to recognize fault diagnosis factors. A novel approach to charging and discharging, as well as the diagnosis of local anomalies, is put forth, utilizing switching networks. Methods: By controlling the capacitors of multiple solar cells and supercapacitors to work together, it is possible to compensate for the shortage of photovoltaic power. The performance of fault diagnosis is optimized by combining principal component analysis and binary K-means clustering, which completes the fault diagnosis of capacitors. Results: The experimental results show that the research method can increase the maximum output power of photovoltaic by 32.9% under multi-layer shadows. In the charging state of the training set, the number of abnormal capacitors is 6, and the number of normal capacitors is 12, and both of them are in accordance with the preset value. The number of abnormal capacitors and normal capacitors in the discharge state is the same as that in the charging state, which is also 6 and 12. Conclusion: The research method can effectively address the issue of unbalanced energy storage battery packs and minimize the impact of local shadows on photovoltaic systems. In comparison to fuzzy C-means clustering, this method requires fewer iterations, enables faster fault diagnosis, and produces more accurate clustering results. It can provide technical support for diagnosing local abnormalities in the charging and discharging of solar cell capacitors. [ABSTRACT FROM AUTHOR]

[Display omitted] Coupling TiO 2 within N -doped porous carbon (NPC) is essential for enhancing its Na+ storage performance. However, the role of different N configurations in NPC in improving the electrochemical performance of TiO 2 is currently unknown. In this study, melamine is deliberately incorporated as a pore-forming agent in the self-assembly process of metal organic framework precursors (NH 2 -MIL-125(Ti)). This intentional inclusion of melamine leads to the one-pot and in-situ formation of highly active edge-N, which is vital for the development of TiO 2 /NPC with exceptional reactivity. Electrochemical performance characterization and density functional theory (DFT) calculation indicate that the interaction between TiO 2 and pyridinic-N enriched NPC can effectively narrow the bandgap of TiO 2 /NPC, thereby significantly improving electron/ion transfer. Additionally, the abundant mesoporous channels, high N content and oxygen vacancies also contribute to the fast reaction kinetics of TiO 2 /NPC. As a result, the optimized TiO 2 /NPC-M, with high proportion of pyridinic-N (44.1 %) and abundant mesoporous channels (97.8 %), delivers high specific capacity of 282.1 mA h−1 at 0.05 A g−1, superior rate capability of 177.3 mA h−1 at 10 A g−1, and prominent capacity retention of 89.3 % over 5000 cycles even under ultrahigh 10 A g−1. Furthermore, the TiO 2 /NPC-M//AC sodium ion capacitors (SIC) device achieves a high energy density of 136.7 Wh kg−1 at 200 W kg−1. This research not only offers fresh perspectives on the production of high-performance TiO 2 -based anodes, but also paves the way for customizing other active materials for energy storage and beyond. [ABSTRACT FROM AUTHOR]

A 16-bit 125 MS/s pipelined analog-to-digital converter (ADC) implemented in a 0.18 μ m CMOS process is presented in this paper. A sample-and-hold amplifier-less (SHA-less) modified 2.5-bit front-end is adopted, which splits the sampling capacitor in half to eliminate the common-mode voltage buffer. The multiplying-digital-to-analog converter (MDAC) in the first pipeline stage is modified by reusing the sampling capacitor in a foreground digital calibration for improving the ADC linearity. This design can circumvent a dedicated reference buffer to generate the calibration voltages at all comparator thresholds. By calibrating the ADC in the digital domain, the integral non-linearity (INL) is improved from −9.2/10 LSB to −3/2.2 LSB, and the spurious-free dynamic range (SFDR) is optimized by over 8dB. The ADC consumes 154mW (reference buffer and clock included) from a 1.8 V supply. [ABSTRACT FROM AUTHOR]

The phenomenon of surface charging, known as contact electrification or tribocharging, has wide-ranging applications but also notable hazards. Precisely measuring surface charge density in insulating materials is crucial for optimizing tribocharging and mitigating adverse effects. Although the vibrating capacitor method is commonly used for this purpose, its principle, designed for conductive materials, limits direct application to insulating surfaces, leaving the relationship between measured surface potential and surface charge density unclear. To address this issue, this study simulated the process of measuring the surface potential of insulating materials using Comsol simulations. It analyzed the effects of charged area size, probe height, and probe position, and utilized the spatial distribution of potential measurement values of surface point charges to derive an integral relationship between the distribution of measured surface potential values and the distribution of surface charge density. The integral relationship of surface potential distribution under different forms of surface charge density distributions calculated from this formula largely matches the numerical simulation results. Based on this, a relationship between the distribution of surface charge density and surface potential measurement values was further derived. This relationship can be used for measuring the surface charge density of insulating materials. [ABSTRACT FROM AUTHOR]

The utilization of a zirconium oxide (ZrO2) thin film as the insulator in a metal–insulator–semiconductor (MIS) capacitor to enhance the characteristics of thin‐film transistors is investigated. Although the high crystallinity of ZrO2 is favorable to achieving higher capacitance density in metal–insulator–metal capacitors with ZrO2 thin films, it decreases the capacitance with increasing applied bias in Mo/ZrO2/InGaZnO (IGZO)‐structured MIS capacitors. Through comprehensive physical, chemical, and electrical characterizations, this study investigated the mechanism underlying the decreasing capacitance with increasing the applied bias in the accumulation state of the Mo/ZrO2/IGZO‐structured MIS capacitor depending on the crystallinity of ZrO2. Furthermore, the investigation identifies the optimal crystal structure of ZrO2 thin films for IGZO‐based MIS capacitors, highlighting the importance of forming meso‐crystalline structures in high dielectric constant (k) materials to enhance the k value and mitigating the decrease in capacitance caused by the accumulated carrier loss through grain boundaries of ZrO2. [ABSTRACT FROM AUTHOR]

The inerter was introduced as a mechanical counterpart to the electrical capacitor, completing the force-current analogy. This is a one-port, twoterminal device in which the equal and opposite forces exerted at its terminals are proportional to the relative acceleration between them. Within this relationship, the "inertance" is the coefficient of proportionality and carries the unit of mass. This implies that the inerter can exert an inertial force at its terminals, effectively representing a virtual mass. Due to these properties, inerters have gained popularity, finding applications as components of vibration control systems and energy harvesters. Derived from passive inerters, semiactive inerters are integrated with active control systems to regulate their inertance. Since their introduction, semi-active inerters have been pivotal in situations demanding active monitoring of natural frequency or control force, generally outperforming their passive counterparts. While numerous significant reviews on passive inerters and their applications have been published in respected journals, dedicated literature reviews on semi-active inerters remain scarce. This review seeks to bridge this gap, offering a comprehensive literature review on semi-active inerters and highlighting research challenges and opportunities. Given the novelty of semi-active inerters, they present a fascinating area of study. [ABSTRACT FROM AUTHOR]

Nickel oxide nanoparticles (NiO NPs) are synthesized using olive leaf extract (OLE), which contains a range of polyphenols. These polyphenols serve as both reducing and capping agents, stabilizing the nanoparticles. Aqueous nickel acetate is employed as a precursor. Simultaneously, exfoliated graphene (EG) is obtained via electrochemical exfoliation of graphite in aqueous solutions. These materials were employed as electroactive components in supercapacitor applications. Characterization of NiO and EG involved thermogravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron spectroscopy (XPS), and scanning/transmission electron microscopy (SEM/TEM), alongside Brunauer−Emmett−Teller (BET) analysis, confirming the formation of crystalline NiO NPs with a cubic phase and Fm-3m space group. Micrographs revealed nanoscale dimensions for both NiO and EG with a substantial surface area, as verified by BET analysis. Symmetric (NiO/NiO, EG/EG) and asymmetric (NiO/EG) supercapacitors were fabricated using the doctor blade method. Electrode evaluation, employing field-emission scanning electron microscopy FESEM, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), demonstrated promising morphological and electrochemical characteristics. At low scan rates, both symmetric and asymmetric supercapacitors exhibited a notable gravimetric capacitance (221, 111, and 162 F g–1 at 1 mV s–1). Additionally, they revealed higher power density (173, 137, and 161 W kg–1 at 10 mV s–1), showcasing pseudocapacitive and electric double-layer capacitor (EDLC) behavior for NiO NPs and EG, respectively. This research significantly contributes valuable insights by presenting a sustainable synthesis route for NiO NPs, developing high-performance supercapacitor electrodes, and achieving a comprehensive understanding of the electrochemical behavior of NiO NPs and EG. [ABSTRACT FROM AUTHOR]

This study introduces an innovative filter topology capable of providing simultaneous positive and negative gain outputs for one-fractional order LP, with high-pass, all-pass, and fractional-order shelving filter responses. The circuit, utilizing multi-output second-generation current-controlled conveyors, stands out as the first to deliver ten outputs, incorporating both integer and fractional-order filter responses, without requiring additional components. Its current-mode design simplifies the process, employing minimal active and grounded passive elements, making it appropriate for low-voltage/low-power applications. The filter utilizes fifth-order Oustaloup approximation and Foster type-I RC networks for fractional-order capacitors, providing enhanced control over the transition slope. PSpice simulations confirmed a 1 kHz cut-off, showcasing low power consumption, minimal noise, and a wide dynamic range, positioning the filter as suitable for sensors, control, and acoustic applications. [ABSTRACT FROM AUTHOR]

The modular multilevel converter (MMC) is a research hotspot in medium-voltage and high-voltage applications. The measurement offset error would cause an increase in the monitoring error of the submodule (SM) capacitance of the MMC, affecting the estimation accuracy of the SM capacitance monitoring. This paper proposes a capacitor monitoring strategy based on the offset error compensation, where two reasonable capacitor monitoring periods are selected in one fundamental period under the proposed voltage-balancing control (VBC) based on the virtual capacitor voltage (VCV) to compensate for the offset error impact on the capacitance monitoring. The proposed strategy can effectively eliminate the offset error impact on the capacitance monitoring, which ensures the accuracy of the SM capacitance monitoring in the MMCs. The effectiveness of the proposed monitoring strategy is confirmed by the simulations and experiments. [ABSTRACT FROM AUTHOR]

In industry, to improve the power factor in low-voltage power substations, a power factor controller (the most used method) can be installed which connects capacitors banks (connected, or not, with coils) in the electrical installation. The most important parameters of power engineering are the power factors that indicate the efficiency of energy use. Currently, many non-linear consumers (more single-phase than three-phase) are used on low voltages. Harmonics (currents and/or voltages) are the most important dynamic component of power quality, affecting electrical equipment performance and also reducing power factors. The purpose of this analysis is to increase the displacement power factor and to decrease the total harmonic distortion (for the current) in the conditions where there are linear and non-linear consumers, where the power factor must be improved with capacitors banks. Relevant different consumers have been selected for both the industry and the home sector, as follows: inductive motors that are linear, inductive consumers, compact fluorescent lamps that are non-linear, and capacitive consumers. This analysis was carried out depending on the number of steps used for the power factor controller, the values of the capacitors banks, the AC reactor (connected in series with all consumers), and the LC shunt filters. For a slight deformation regime, a large number of capacitors banks with different values ensure a finer adjustment of the displacement factor. The maximum number of steps that regulators can command should not necessarily be used (the reliability of the installation decreases with the increase in the number of capacitors banks), but a reduced number of steps can be used, which can lead to higher values of displacement power factors. To improve the deforming regime and to increase the displacement power factor, the use of LC shunt filters, connected to a small number of steps, will also increase the displacement power factor (over 0.9) and decrease the total harmonic distortion (up to 7–10%) for the current. Weaker results were obtained with AC reactors connected to the power supply phases of consumers and, if a larger number of stages were used, to which LC shunt filters were connected, these filters become difficult to calibrate (resonances occur). [ABSTRACT FROM AUTHOR]

Outstanding materials and novel device structures are key factors in satisfying the increasing demand for energy storage. Li‐ion capacitors, as one typical model of asymmetric supercapacitors, benefit from the battery's ultrahigh specific energy and supercapacitor's superlarge specific power to meet the balanced electrochemical energy storage requirements. The inherent and irreplaceable advantages make spinel lithium titanate an optimal candidate for power batteries and Li‐ion capacitors. However, upstream market volatility, including price spikes and supply shortages, tremendously threatens spinel lithium titanate's production, sale, and application. Lithium hydroxide hydrate is an alternative raw material to synthesize spinel lithium titanate synthesis, which can help address these concerns. The indirect production path generates high‐quality lithium carbonate as an intermediate product. Spinel lithium titanate is synthesized preferably via another economically and technically more efficient method that skips the isolation step after carboxylation. The electrochemical performance of the resulting spinel lithium titanate is evaluated to be better than that of commercial competitors. The spinel lithium titanate negative electrode‐based lithium‐ion capacitor achieves a specific energy of 89.5 Wh kg−1. These results demonstrate the success of efforts to find a feasible and affordable synthesis route to mitigate market risks. [ABSTRACT FROM AUTHOR]

This study proposes an optimal approach for enhancing the quality of a weak electrical power distribution system by utilizing thyristor‐controlled series capacitors (TCSC). The proposed approach considers various system components, including shunt capacitors and distributed generators that rely on renewable energy sources, which are characterized by uncertainty due to changing weather conditions. The proposed system maximizes the benefits of these components by updating its parameters to improve the distribution power system's quality under all operating conditions, which change due to the varying energy generated by the distributed generators and load changes. The optimal TCSC values are calculated for all operating conditions using the Hyper‐Spherical Search with graded objective functions management strategy (HSSA‐GOFMS) algorithm. The GOFMS converts all restrictions into objective functions with limits and prioritizes the search for objectives according to a sequential system of priorities. This strategy prevents the possibility of non‐convergence. The results demonstrate the effectiveness of the proposed approach in improving the performance quality of a weak electrical distribution system. The proposed strategy achieves the target voltage level limits within nominal values, even with the interference of the system with generators distributed at variable power levels. Furthermore, the proposed approach enhances the performance quality of the system under a wide range of load changes. [ABSTRACT FROM AUTHOR]

There is an increasing desire to utilize complex functional electronic materials such as ferroelectrics in next-generation microelectronics. As new materials are considered or introduced in this capacity, an understanding of how we can process these materials into those devices must be developed. Here, the effect of different fabrication processes on the ferroelectric and related properties of prototypical metal oxide (SrRuO3)/ferroelectric (BaTiO3)/metal oxide (SrRuO3) heterostructures is explored. Two different types of etching processes are studied, namely, wet etching of the top SrRuO3 using a NaIO4 solution and dry etching using an Ar+-ion beam (i.e., ion milling). Polarization-electric-field hysteresis loops for capacitors produced using both methods are compared. For the ion-milling process, it is found that the Ar+ beam can introduce defects into the SrRuO3/BaTiO3/SrRuO3 devices and that the milling depth strongly influences the defect level and can induce a voltage imprint on the function. Realizing that such processing approaches may be necessary, work is performed to ameliorate the imprint of the hysteresis loops via ex situ "healing" of the process-induced defects by annealing the ferroelectric material in a barium-and-oxygen-rich environment via a chemical-vapor-deposition-style process. This work provides a pathway for the nanoscale fabrication of these candidate materials for next-generation memory and logic applications. [ABSTRACT FROM AUTHOR]

This article presents a comprehensive comparative evaluation of a three-phase Three-Level (3L) Flying Capacitor Converter (FCC) and a Stacked Polyphase Bridge Inverter (SPBI), specifically a converter system formed by two Series-Stacked Two-Level three-phase Converters (2L-SSC), for the realization of a 7.5 kW Integrated Motor Drive (IMD) with a high short-term overload capability. The 2L-SSC requires a motor with two three-phase windings and a split DC-link, but uses standard six-switch, two-level transistor configurations. In contrast, the bridge legs of the 3L-FCC feature flying capacitors whose voltages must be actively balanced. Despite the 800 V DC-link voltage, both topologies employ the same set of 650 V GaN power transistors, i.e., the same total chip area, and if operated at the same switching frequency, show identical semiconductor losses. Electric Discharge Machining (EDM) damage of the motor bearings is a relevant issue caused by the common-mode (CM) voltages of the inverter stage. The high effective switching frequency of the 3L-FCC and the possibility of CM voltage canceling in the 2L-SSC facilitate mitigation of EDM by means of CM chokes, whereby a substantially smaller CM choke with lower losses suffices for the 2L-SSC; based on exemplary designs, the 2L-SSC features only about 75% of the total volume and 85% of the nominal losses of the 3L-FCC. If, alternatively, motor-friendliness is maximized by including DC-referenced sine-wave output filters, the 3L-FCC's higher effective switching frequency and the 2L-SSC's need for two sets of filters due to the dual-winding-set motor change the outcome. In this case, the 3L-FCC features only about 60% of the volume and only about 55% of the 2L-SSC's nominal losses. [ABSTRACT FROM AUTHOR]

In this study, we investigate the electrochemical properties of a nickel oxide-carbon (NiO/C) material, synthesized in the form of highly porous carbon nanofibers through the electrospinning of polymers such as polyacrylonitrile (PAN) and polystyrene (PS) followed by a carbonization process. The primary focus of this work is to determine the optimal mixing ratio for the hybrid material composed of NiO and carbon. While it is widely acknowledged that supercapacitor materials benefit from having a high specific surface area, our findings reveal that hybrid carbon nanofibers with a 45% specific carbon-to-nickel oxide ratio exhibit significantly enhanced capacitance (39.9 F g−1). This outcome suggests the promising potential of our materials as an energy storage material for hybrid supercapacitors, combining the advantages of electric double-layer capacitors (EDLC) and Pseudo capacitors (Pseudo). [ABSTRACT FROM AUTHOR]

As electrochemical research undergoes rapid technological progression, the acquisition of substantial amounts of electrochemical impedance spectra (EIS) becomes increasingly feasible. Yet, this advancement introduces intricate challenges in data processing, automation, and interpretation. This paper delves into the sufficiency of unsupervised machine learning (ML) and in particular dimensionality reduction methods in decoding EIS complexities, examining its strengths, limitations, and potential pathways for optimization. As we navigated the intricacies of non‐linear dimensionality reduction, spotlighting t‐distributed stochastic neighbor embedding (t‐SNE) and uniform manifold approximation and projection (UMAP) algorithms, a pattern emerged: these techniques excel at categorizing divergent impedance spectra but show limitations when faced with analogous circuit configurations, especially those substituting a capacitor with a constant phase element. This observation not only underscores a limitation but also accentuates that unsupervised ML approaches, alone, may not fully unravel the nuances of EIS spectra. In the concluding section of our manuscript, we discuss the implications of this finding from a practical standpoint, particularly for electrochemists seeking to apply these methods in their work. [ABSTRACT FROM AUTHOR]

The dual-ion (B and F) co-doped hierarchical porous carbon with suitable pore size and interconnected network was prepared by a facile activated strategy. The synergistic effect of B and F adsorption and the coupling mechanism between suitable pore size and vacancy defects not only can enhance Zn2+ storage capability but also effectively facilitate electron and ion transfer behavior in porous carbon materials. This work provides a comprehensive illustration and new insights for the rational design of heteroatom-doped porous carbon materials cathode, thereby offering promising potential for practical applications in electrochemical energy storage devices. [Display omitted] • The B/F groups anchored into the hierarchically porous carbon cathode was obtained. • The synergistic effect on dual-ion adsorption enhances the Zn2+ storage capability. • The energy density of 175.8 Wh kg−1 at a power density of 159.1 W kg−1 is achieved. • BFPC-2//Zn delivers a superior capacity retention of 96.9% after 20,000 cycles. Aqueous zinc-ion capacitors (AZICs) are considered potential energy storage devices thanks to their ultrahigh power density, high safety, and extended cycling life. Carbon-based materials widely used as cathodes in AZICs face challenges, such as inappropriate pore sizes, poor electrolyte–electrode wettability, and insufficient vacancy defects and active sites. These limitations hinder efficient energy storage capacity and long-term stability. To address these issues, the B and F co-doped hierarchical porous carbon cathode materials (BFPC) are constructed through a facile annealing treatment process. The BFPC-2//Zn device exhibited high capacities of 222.4 and 118.3 mAh g−1 at current densities of 0.2 and 10 A g−1, respectively. Notably, the BFPC-2//Zn device demonstrated long-term cycling stability with a high capacity retention of 96.9 % after 20,000 cycles at 10 A g−1. Additionally, the assembled BFPC-2 based AZICs displayed a maximum energy density of 175.8 Wh kg−1 and an ultrahigh power density of 17.3 kW kg−1. Mechanism studies revealed that the exceptional energy storage ability and charge-transfer process of the BFPC cathode are attributed to the synergistic effect of B and F heteroatoms and the coupling effect between vacancy defects and pore size. This work presents a novel design strategy by incorporating B and F active sites into hierarchical porous carbon materials, providing enhanced energy storage capabilities for practical application in AZICs. [ABSTRACT FROM AUTHOR]

The supermolecule-mediated method is employed to prepare an organic molecule aggregate (OMA) precursor called MCAL in which the dopant agent (melamine-cyanuric acid supramolecular (MCA)) and biomass molecule (alkali lignin (AL)) are uniformly mixed. Direct pyrolysis of OMA yields lignin-derived highly nitrogen-doped turbine-like carbon (LNTC), which serves as a high-performance anode for potassium-ion capacitors. [Display omitted] Potassium-ion hybrid capacitors (PIHCs) represent a burgeoning class of electrochemical energy storage devices characterized by their remarkable energy and power densities. Utilizing amorphous carbon derived from sustainable biomass presents an economical and environmentally friendly option for anode material in high-rate potassium-ion storage applications. Nevertheless, the potassium-ion storage capacity of most biomass-derived carbon materials remains modest. Addressing this challenge, nitrogen doping engineering and the design of distinctive nanostructures emerge as effective strategies for enhancing the electrochemical performance of amorphous carbon anodes. Developing highly nitrogen-doped nanocarbon materials is a challenging task because most lignocellulosic biomasses lack nitrogen functional groups. In this work, we propose a general strategy for directly carbonizing supermolecule-mediated lignin organic molecular aggregate (OMA) to prepare highly nitrogen-doped biomass-derived nanocarbon. We obtained lignin-derived, highly nitrogen-doped turbine-like carbon (LNTC). Featuring a three-dimensional turbine-like structure composed of amorphous, thin carbon nanosheets, LNTC demonstrated a capacity of 377 mAh g−1 when used as the anode for PIHCs. This work also provides a new synthesis method for preparing highly nitrogen-doped nanocarbon materials derived from biomass. [ABSTRACT FROM AUTHOR]

Highlights Achieving ultrahigh energy-storage density (7.19 J cm−3) and outstanding storage efficiency (93.8%) at 460 kV cm−1 in BNT-based relaxor ferroelectric ceramics under a moderate electric field. Superior energy-storage performance accomplished through meticulous regulation of permittivity, enhancement of insulation quality, and strategic domain engineering via chemical formula optimization. The intricate structure–property relationship elucidated with precision using high-resolution transmission electron microscopy.

This paper presents a low-distortion and low-power multi-stage noise-shaping (MASH) architecture Sigma-Delta (Σ Δ) modulator with double-sampling. The modulator uses a cascade of integrator feed-forward (CIFF) structure as a cascaded modulator in a MASH architecture. Since the CIFF structure provides a feedforward path from the input signal to the quantizer, the input signal is directly transmitted to the output without loop processing, relaxing the linearity requirement of the modulator, reducing performance requirements for the OTA and harmonic distortion. Double-sampling technique is adopted in the first integrator to double the sampling rate, improving the accuracy of the modulator without the increase of power consumption. In order to eliminate the influence of capacitor mismatch in the sampling network, a fully floating differential switched capacitor (SC) feedback digital-to-analog (DAC) is used in the integrator. The simulation results show that the Σ Δ modulator achieves 113 dB signal-to-noise and distortion ratio (SNDR) and the power consumption is 3.15 mW from a 5 V power supply. [ABSTRACT FROM AUTHOR]

The lithium-ion capacitor (LIC) is a new type of hybrid energy storage device, which combines the advantages of lithium-ion battery and electric double layer capacitor. To achieve efficient and reliable application of LIC in practical scenarios, accurate model and state estimation method are needed. In this work, the electrical behavior of LIC is studied, which is then described by the Thevenin model. A multi-innovation filter- (MIF-) based coestimation method is proposed, in which the multi-innovation linear Kalman filter (MI-LKF) is used for model parameter identification, the multi-innovation cubature Kalman filter (MI-CKF) is used for state of charge estimation, and the multi-innovation extended Kalman filter (MI-EKF) is used for state of health estimation. Compared to traditional methods, this method can significantly improve estimation accuracy by only expanding the innovation used to update the state from a single moment to multiple moments. The experimental results indicate that the estimation errors of SOC and SOH can be constrained within ±0.5%. In addition, the proposed method has good robustness and can achieve high-precision state estimation even in the face of noise interference, uncertain initial values of the algorithm, and uncertain starting operating points. [ABSTRACT FROM AUTHOR]

The AC power system strength exhibits time-varying characteristics during operation, thereby affecting the filtering performance of filters in the system. Failure to account for this variability may result in the harmonic levels exceeding permissible limits under specific power system strength, thereby affecting the normal operation of the power system. Consequently, building upon the existing filtering technique based on parallel-connected fixed capacitors for LCC-HVDC systems, a method for tuning the parameters of parallel-connected capacitors is proposed, thereby the capacitance range meets the filtering requirements under various system strengths. [ABSTRACT FROM AUTHOR]

Zinc-ion hybrid capacitors (ZICs) can achieve high energy and power density, ultralong cycle life, and a wide operating voltage window, and they are widely used in wearable devices, portable electronics devices, and other energy storage fields. The design of advanced ZICs with high specific capacity and energy density remains a challenge. In this work, a novel kind of V, N dual-doped Ti3C2 film with a three-dimensional (3D) porous structure (3D V-, N-Ti3C2) based on Zn-ion pre-intercalation can be fabricated via a simple synthetic process. The stable 3D structure and heteroatom doping provide abundant ion transport channels and numerous surface active sites. The prepared 3D V-, N-Ti3C2 film can deliver unexpectedly high specific capacitance of 855 F g−1 (309 mAh g−1) and demonstrates 95.26% capacitance retention after 5000 charge/discharge cycles. In addition, the energy storage mechanism of 3D V-, N-Ti3C2 electrodes is the chemical adsorption of H+/Zn2+, which is confirmed by ex situ XRD and ex situ XPS. ZIC full cells with a competitive energy density (103 Wh kg−1) consist of a 3D V-, N-Ti3C2 cathode and a zinc foil anode. The impressive results provide a feasible strategy for developing high-performance MXene-based energy storage devices in various energy-related fields. [ABSTRACT FROM AUTHOR]

Due to the unique properties of room temperature ionic liquids (RTILs), most researchers' interest in RTIL-based electrolytes in electric double-layer capacitors (EDLCs) stems from molecular simulations, which are different from experimental scientific research fields. The knowledge of RTIL-based electrolytes in EDLCs began with a supposition obtained from the results of molecular simulations of molten salts. Furthermore, experiments and simulations were promoted and developed rapidly on this topic. In some instances, the achievements of molecular simulations are ahead of even those obtained from experiments in quantity and quality. Molecular simulations offer more information on the impacts of overscreening, quasicrowding, crowding, and underscreening for RTIL-based electrolytes than experimental studies, which can be helpful in understanding the mechanisms of EDLCs. With the advancement of experimental technology, these effects have been verified by experiments. The simulation prediction of the capacitance curve was in good agreement with the experiment for pure RTILs. For complex systems, such as RTIL–solvent mixtures and RTIL mixture systems, both molecular simulations and experiments have reported that the change in capacitance curves is not monotonous with RTIL concentrations. In addition, there are some phenomena that are difficult to explain in experiments and can be well explained through molecular simulations. Finally, experiments and molecular simulations have maintained synchronous developments in recent years, and this paper discusses their relationship and reflects on their application. [ABSTRACT FROM AUTHOR]

In power engineering, the importance of maintaining a high power factor in low-voltage electrical installations is known. In power substations for industry, the usual method of coupling is to use an automatic power factor controller which connects capacitors banks (with electromagnetic contactors). Sometimes, AC reactors are connected to the phases of the capacitors banks (to reduce transient phenomena and the deforming regime), depending on the desired value of the power factor. This paper presents an analysis (more focused on experimentation) of a low-cost system for automatic regulation of the power factor with a reduction in transients and an increase in the life of contactors (eliminating the electric arc during switching on), with capacitors banks for low-voltage three-phase installations that connect the capacitors banks by means of one three-phase solid-state relay (an expensive device for a quality device; one is used for all capacitors banks) and using several electromagnetic contactors. The automatic power factor adjustment system has a controller with a microprocessor with six outputs, controlled by the phase shift between the current (measured with a current transformer proportional to the current in a bar) and the phase voltage, which is part of a system of distribution bars (L1,2,3, N) from which electrical consumers (e.g., induction motors) are supplied. To reduce transients when connecting capacitors banks, a three-phase solid-state relay and two related electromagnetic contactors are used for each capacitors bank. The automatic power factor controller is connected to two low-capacity PLCs that control the logic of connecting the capacitors banks to reduce transients. By using the proposed regulation system, a cheaper control solution is obtained compared to the use of one solid-state relay for each capacitors banks, under the conditions in which the power factor adjustment is made as in the classic solution. If twelve capacitors banks are used, the proposed installation is 22.57% cheaper than the classical power factor regulation installation. [ABSTRACT FROM AUTHOR]

High-energy and ultra-stable zinc-ion hybrid capacitors can be constructed based on suitable self-stacking interaction precursor-mediated carbon cathode with self-doped hierarchical porous structure and surface-opened macropores. [Display omitted] Understanding the self-stacking interactions in precursors can facilitate the preparation of high-performance carbon materials and promote the commercial application of zinc ion hybrid capacitors (ZIHCs). Here, a π-conjugated molecule mediated pyrolysis strategy is presented to prepare carbon materials. Taking intermolecular force simulation (reduced density gradient plots) as a guide, the relationship between the self-stacking interactions in π-conjugated molecules and the structural parameters of carbon materials can be extrapolated. The resultant self-doped hierarchical porous carbons (NHPCs) derived from 1, 8, 4, 5-naphthalenetetracarboxdiimide with suitable self-stacking interactions empower the highest specific surface areas (2038 m2/g) and surface opening macropores. The NHPCs-based ZIHCs deliver a high capacity of 220 mAh/g, a high energy density of 149.5 Wh kg−1 and a super-stable cycle lifespan with 93.2 % capacity retention after 200, 000 cycles. The excellent electrochemical performance roots in the superior hierarchical porous structure with surface opening macropores, which guarantees the structural stability of carbon cathodes upon repeated rounds. Meanwhile, the heteroatom doping further relieves the kinetics concern of Zn2+ uptake/removal to enhance O-Zn-N binding particularly at high discharge currents. Besides, the proton-assisted Zn2+ dual-ion storage mechanism plays an essential role in the energy storage process. This work demonstrates a facile synthesis method and advances the fundamental understanding of its dual-ion storage mechanism. [ABSTRACT FROM AUTHOR]

In this paper, a new negative lossless grounded capacitance multiplier (GCM) circuit based on a Current Feedback Operational Amplifier (CFOA) is presented. The proposed circuit includes a single CFOA, four resistors, and a grounded capacitor. In order to reduce the power consumption, the internal structure of the CFOA is realized with dynamic threshold-voltage MOSFET (DTMOS) transistors. The effects of parasitic components on the operating frequency range of the proposed circuit are investigated. The simulation results were obtained with the SPICE program using 0.13 µm IBM CMOS technology parameters. The total power consumption of the circuit was 1.6 mW. The functionality of the circuit is provided by the capacitance cancellation circuit. PVT (Process, Voltage, Temperature) analyses were performed to verify the robustness of the proposed circuit. An experimental study is provided to verify the operability of the proposed negative lossless GCM using commercially available integrated circuits (ICs). [ABSTRACT FROM AUTHOR]

The decay of the electrical energy in a resistor-vacuum capacitor circuit is shown to involve multiple relaxation processes, with dramatically different time constants. This is measured using a vacuum capacitor to eliminate the effect of a dielectric between the plates (polypropylene capacitors are shown to exhibit similar behavior). A simple phenomenological model accounts for this behavior in spite of the difficulty in applying Maxwell's equations to such a circuit. These results will lead to a revision of our understanding of the physics of circuits, having particular impact on applications that use capacitors as sensors in collecting precision data (such as found in quantum measurements and dielectric spectroscopy). [ABSTRACT FROM AUTHOR]

Today, multilevel inverters are widely utilized in various applications. Reducing the number of components in the design of these converters is one of the crucial goals so that they have less volume and cost. This paper presents a single‐source structure for a multilevel switched‐capacitor inverter with voltage boost capability. The proposed structure can generate 25 sinusoidal‐like step voltage levels with a six times amplitude increase compared to the input. This converter uses only one direct current (DC) power source, 14 switches, and four capacitors. The nearest level control switching method has been used to control the converter, create voltage levels, and select the switching modes. A comprehensive comparison has been made with other recently presented structures to demonstrate the efficiency of the proposed structure. The advantages of the proposed structure include using only one DC voltage source, the ability to increase the output voltage six times compared to the input, the use of fewer power electronics components compared to the number of voltage levels, proper efficiency, self‐balancing of capacitors, and as a result, the lower cost. The performance accuracy of the proposed converter has been simulated in the MATLAB Simulink environment and then evaluated by a laboratory prototype. [ABSTRACT FROM AUTHOR]

This work presents an optimal methodology based on an augmented, improved, subtraction-average-based technique (ASABT) which is developed to minimize the energy-dissipated losses that occur during electrical power supply. It includes a way of collaborative learning that utilizes the most effective response with the goal of improving the ability to search. Two different scenarios are investigated. First, the suggested ASABT is used considering the shunt capacitors only to minimize the power losses. Second, simultaneous placement and sizing of both PV units and capacitors are handled. Applications of the suggested ASAB methodology are performed on two distribution systems. First, a practical Egyptian distribution system is considered. The results of the simulation show that the suggested ASABT has a significant 56.4% decrease in power losses over the original scenario using the capacitors only. By incorporating PV units in addition to the capacitors, the energy losses are reduced from 26,227.31 to 10,554 kW/day with a high reduction of 59.75% and 4.26% compared to the initial case and the SABT alone, respectively. Also, the emissions produced from the substation are greatly reduced from 110,823.88 kgCO2 to 79,189 kgCO2, with a reduction of 28.54% compared to the initial case. Second, the standard IEEE 69-node system is added to the application. Comparable results indicate that ASABT significantly reduces power losses (5.61%) as compared to SABT and enhances the minimum voltage (2.38%) with a substantial reduction in energy losses (64.07%) compared to the initial case. For both investigated systems, the proposed ASABT outcomes are compared with the Coati optimization algorithm, the Osprey optimization algorithm (OOA), the dragonfly algorithm (DA), and SABT methods; the proposed ASABT shows superior outcomes, especially in the standard deviation of the obtained losses. [ABSTRACT FROM AUTHOR]

Detecting the moisture content of grain accurately and rapidly has important significance for harvesting, transport, storage, processing, and precision agriculture. There are some problems with the slow detection speeds, unstable detection, and low detection accuracy of moisture contents in corn harvesters. In that case, an online moisture detection device was designed, which is based on double capacitors. A new method of capacitance complementation and integration was proposed to eliminate the limitation of single data. The device is composed of a sampling mechanism and a double-capacitor sensor consisting of a flatbed capacitor and a cylindrical capacitor. The optimum structure size of the capacitor plates was determined by simulation optimization. In addition to this, the detection system with software and hardware was developed to estimate the moisture content. Indoor dynamic measurement tests were carried out to analyze the influence of temperature and porosity. Based on the influencing factors and capacitance, a model was established to estimate the moisture content. Finally, the support vector machine (SVM) regressions between the capacitance and moisture content were built up so that the R2 values were more than 0.91. In the stability test, the standard deviation of the stability test was 1.09%, and the maximum relative error of the measurement accuracy test was 1.22%. In the dynamic verification test, the maximum error of the measurement was 4.62%, less than 5%. It provides a measurement method for the accurate, rapid, and stable detection of the moisture content of corn and other grains. [ABSTRACT FROM AUTHOR]