Breakdown Energy Research Articles

An Emerging Mineral‐Based Dielectric Material: Intrinsic Dielectric Properties and Modulated

AbstractHigh energy density polymer nanocomposites reinforced with high dielectric constant ferroelectric nanoparticles exhibit great potential for energy storage applications in modern electronic and electrical systems. However, further improvements in the Ue of polymer nanocomposites with a higher breakdown strength (Eb) is of utmost importance. Tuning the permittivity from the filler center to the surrounding matrix in composites can alleviate local charge concentrations. Here, a gradient dielectric constant buffer layer is constructed via induced selectively titanium dioxide is inserted into the multilayer aluminosilicate. This gradient‐structured buffer layer remarkably weakened the charge density around the ferroelectric particles, which gave rise to high breakdown strength and increased the energy density of the polymer nanocomposites. Furthermore, the density functional theory (DFT) calculation reveals an active charge transfer between buffer layer and poly(vinylidene fluoride‐co‐hexafluoropropylene). The space charge density distribution is simulated via finite element methods to verify the experimental dielectric breakdown results in the nanocomposite films. Therefore, this work provides a new strategy to balance the coupling relationship between energy density and breakdown strength.

Energy-Saving Manufacturing System Design with Two Geometric Machines

In recent years, due to increasing energy costs and deteriorating environmental conditions, manufacturing enterprises have become more concerned with energy efficiency. This paper is dedicated to minimizing energy consumption while maintaining the target productivity of a two-machine geometric serial line. To address this problem, we propose a nonlinear model under productivity constraints, where the system energy consumption consists of three components, namely, the setup, the idle, and the normal working energy consumption. By analyzing the properties of the energy consumption function, a new heuristic method, i.e., the energy consumption minimization (ECM) algorithm, is proposed to obtain the optimal solution. In addition, we extend the formulation to further investigate the energy saving problem with varied buffer capacities and propose an energy-saving (ES) algorithm to solve it based on the problem structure. Furthermore, the effectiveness of the algorithms is verified by designing numerical examples, and the effects of energy consumption parameters, buffer capacity, target productivity, and breakdown probabilities on the total energy consumption and optimal solution are presented.

Signal-to-noise ratio improvements in microwave-assisted laser-induced breakdown spectroscopy

A microwave-assisted laser-induced breakdown spectroscopy (MA-LIBS) was developed to enhance the signal-to-noise ratio (SNR) measurements of alumina oxide plates. A semiconductor-based 2.45 GHz microwave device was coupled to a semiconductor 1064 nm laser source using a helical antenna, which replaced the larger-size capacitor-like antenna. This work was motivated by the applications of laser-induced breakdown spectroscopy (LIBS) in decommissioning of Fukushima Daiichi Nuclear Power Station (FDNPS). When using a 50-meter optical fiber from the main source into the nuclear vessel, the LIBS laser energy was expected to decrease significantly. Using the low laser energy of equal to or less than 2.0 mJ, the MA-LIBS significantly enhanced the excitation of the neutrals of Aluminum (Al) and the background signals contained no continuum emissions. Significant increase of the emission intensities of Al I with the addition of microwave energy was observed which also increased the full-width-half-maximum (FWHM). The correlation of the laser and microwave parameters and the SNR were then analyzed. Results show the logarithmic correlation of the microwave pulse width and microwave energy to the intensity enhancement and SNR which is attributed to the absorption of the microwave energy. This correlation is consistent with variations of laser energy density, laser pulse number, and laser spot diameter. Using a delayed acquisition time, the emission intensities of Al I were only observed with the addition of microwaves. At the experimental threshold of laser breakdown energy using 0.3 mJ, the emission intensity of Al I was only observed with the addition of microwaves. Attempts to duplicate the same SNR measurements using the stainless steel and lead targets were also done. The microwave successfully enhanced the intensity emission and SNR of the Al I, Cr I, and Pb I excited species.

Ultrahigh breakdown strength and energy storage properties of xBiMg0.5Zr0.5O3-(1-x)BaZr0.25Ti0.75O3 thin films

The development of miniaturized and lightweight electronic equipment requires the improvement of the dielectric breakdown strength and energy storage performance of dielectric capacitors. Therefore, in this study, a method for obtaining an amorphous phase by reducing the annealing temperature of a material is proposed to considerably improve the electrical breakdown, and a high-polarized substance is introduced to compensate for the polarization of the material. Lead-free xBiMg0.5Zr0.5O3-(1-x)BaZr0.25Ti0.75O3 (abbreviated as xBMZ-(1-x)BZT, x = 0.01, 0.02, 0.03, 0.04, and 0.05) thin films were prepared on Pt/Ti/SiO2/Si substrates by using the sol-gel spin-coating method. The microstructure with coexisting nanocrystalline and amorphous phases was successfully controlled by reducing the annealing temperature and employing a rapid annealing process. All the films with this microstructure exhibited extremely high breakdown strength, and the effectiveness of this method was verified. When x = 0.04, the ultra-high breakdown strength of 6640 kV/cm, high energy storage density of 81.6 J/cm3 and high energy storage efficiency of 87% were achieved. Moreover, the dielectric and energy storage performance were excellent under temperatures from 20 °C to 200 °C. This study presents a feasible approach for designing new high-performance dielectric capacitors for energy storage devices in the future.

Improvement of high-temperature energy storage performance in polymer dielectrics by nanofillers with defect spinel structure

The electrostatic energy storage performance of polymer dielectrics at high temperature and high electric field can be significantly improved by the incorporation of wide-bandgap, nano-sized particles. It is traditionally believed that the embedded nanoparticles can scatter the hot charges and lead to charge trapping in the interfacial region, which suppress the conduction loss and promote the energy storage performance. In this work, the nano-sized γ-Al2O3 with cubic defect spinel structure and nano-sized α-Al2O3 with a wider bandgap are introduced into a heat-resistant dielectric polymer, respectively, to form two different nanocomposites. The field-dependent energy storage performance, electrical conductivity, and breakdown strength of the polymer nanocomposites at high temperatures, as well as the thermally stimulated depolarization current, are investigated. The results indicate that the intrinsic deep traps introduced by γ-Al2O3 with cubic defect spinel structure are a more critical factor in improving the energy storage performance of the polymer-based composites. We anticipate that our findings reported in this work may help to better guide the selection of nanofillers for high-temperature dielectric polymer nanocomposites.

Influence of rare-earth ion doping on dielectric properties of lithium zinc borate glasses

The dielectric constant (ε′), loss factor (tanδ), and ac conductivity (σac) of 30 Li2O-10 ZnO-(60-x) B2O3: xLn2O3, where (x = 0 and 1) and (Ln = Pr, Nd, Sm, and Eu) were investigated using a frequency range of 102–105 Hz and temperature ranging from 30 to 250 °C in this work. Differential Scanning Calorimetry (DSC) technique was employed to confirm the glassy nature of the materials under study. The dielectric parameters ε′, tanδ, and σac rise when rare-earth ions are added to the glass matrix at any frequency or temperature. Dielectric breakdown and activation energies are lower in doped than in undoped glasses while ac current flows through them at room temperature. Rare-earth ion doping's dielectric parameter values decrease with temperature as atomic number (Z) rises. The dielectric parameter values for the Pr3+ doped glass matrix are the highest. QM tunnelling model was used to describe the ac conduction behaviour of these glasses.

Coupled sliding–decohesion–compression model for a consistent description of monotonic and fatigue behavior of material interfaces

A thermodynamically consistent model proposed in this work introduces a generative symbolic framework for computational components, which can capture the inelastic behavior of interfaces with 3D kinematics in response to monotonic, cyclic, and fatigue loading histories. It contributes to a long list of existing cohesive zone models by introducing novel forms of potentials for free energy, threshold function, and dissipation to deliver the following model properties: (i) the evolution equations derived from the potentials are linked in such a way that damage develops along with the cumulative measure of plastic sliding, (ii) the convex, continuous, and smooth shape of the threshold function introduced in the effective stress domain enables a general and efficient time integration that automatically handles unloading and reloading, and (iii) the non-associative flow potential includes a scalable degree of coupling between normal and tangential damage evolution. The studies performed in the paper demonstrate that these model ingredients lead to a consistent coverage of arbitrary non-proportional loading scenarios in tangential and normal directions. For monotonic loading, the presented examples illustrate the ability of the model to reproduce the shear dilatancy, pressure sensitivity including the vertex effect, stiffness recovery in compression, and abrasion due to sliding. For cyclic fatigue loading, the studies show that the model reflects the link between the hysteretic behavior and the fatigue damage evolution. This link constitutes the basis for a physically sound description of fatigue degradation along material interfaces. It manifests itself in the presented energy breakdown with distinguished fractions of energy release due to damage and plasticity ascribed to normal and tangential directions. Two calibration and validation examples using pull-out tests exposed to monotonic and cyclic loading are provided to show the applicability of the model for the characterization of the bond between steel bars and concrete. A publicly available implementation using a computer algebra system (CAS) is provided in the form of an interactive Jupyter notebook to document the reproducibility of the results.

Roles of Al2O3@ZrO2 Particles in Modulating Crystalline Morphology and Electrical Properties of P(VDF-HFP) Nanocomposites.

Polymer materials with excellent physicochemical and electrical properties are desirable for energy storage applications in advanced electronics and power systems. Here, Al2O3@ZrO2 nanoparticles (A@Z) with a core-shell structure are synthesized and introduced to a P(VDF-HFP) matrix to fabricate P(VDF-HFP)/A@Z nanocomposite films. Experimental and simulation results confirm that A@Z nanoparticles increase the crystallinity and crystallization temperature owing to the effect of the refined crystal size. The incorporation of A@Z nanoparticles leads to conformational changes of molecular chains of P(VDF-HFP), which influences the dielectric relaxation and trap parameters of the nanocomposites. The calculated total trapped charges increase from 13.63 μC of the neat P(VDF-HFP) to 47.55 μC of P(VDF-HFP)/5 vol%-A@Z nanocomposite, indicating a substantial improvement in trap density. The modulated crystalline characteristic and interfaces between nanoparticles and polymer matrix are effective in inhibiting charge motion and impeding the electric conduction channels, which contributes to an improved electrical property and energy density of the nanocomposites. Specifically, a ~200% and ~31% enhancement in discharged energy density and breakdown strength are achieved in the P(VDF-HFP)/5 vol%-A@Z nanocomposite.

Numerical Study on Rolled Strip Pulse Forming Line with Combined Insulation Structure

Rolled strip pulse forming line (RSPFL) with combined insulation structure can effectively increase the breakdown electric strength and energy storage density of pulse forming line by optimization of the edge field enhancement effect. In this paper, a combined insulation (which consists of polyimide and polyvinylidene fluoride films) based RSPFL is investigated theoretically and numerically. Firstly, parameters of the pulse forming line was designed theoretically. Secondly, the finite element software was employed to study the influence of insulation film combination and structural parameters on the electric field distribution and the transmission characteristics. The parameters are then optimized. Finally, combined insulation based RSPFL was successfully used as a single pulse forming line, and a 200 ns quasi-square pulse was obtained on a 2.5 Ω dummy load by simulation. The simulation shows that it has an energy storage density of approximately 19.57 J/L when the PFL is charged to 60 kV.

Evolution of the cavity in a particle dispersion triggered by laser-induced breakdown

Focusing a laser beam to a spot within a particle-laden air flow can cause laser-induced breakdown, which generates a spherically expanding shockwave and ensuing hot gas vortex (HGV). This can cause an initially uniform spatial distribution of static particles to be scattered non-homogeneously, creating a particle void region (or cavity). High-speed schlieren imaging has been applied to investigate the propagation of this shockwave and deformation of the HGV. Evolution of the particle distribution has been captured by a high-speed camera. It has been found that the cavity evolves over three temporal phases: expansion, distortion, and separation. The cavity is first created as the shockwave expels the particles in the radial direction. Next, the cavity is distorted by the HGV and then separates into smaller cavities before finally disappearing due to mixing from the HGV. The temporal and spatial characteristics of the cavity and the mechanism by which it changes in each phase are discussed. Experiments were conducted at three different breakdown energies of 15, 49, and 103 mJ. Propagation speed of the shockwave and the size and strength of the HGV are found to be the main factors controlling this phenomenon.

Significantly Improved Dielectric Breakdown Strength and Energy Density in P(VDF-TrFE-CTFE) Polymer via a Facile Uniaxial Drawing Process

Significantly Improved Dielectric Breakdown Strength and Energy Density in P(VDF-TrFE-CTFE) Polymer via a Facile Uniaxial Drawing Process

Sandwich-structured polymer dielectric composite films for improving breakdown strength and energy density at high temperature

Polymer dielectric capacitor have attracted much attention in the field of electronic power systems recently due to high power density and high breakdown strength. However, with the development of miniaturization and integration, further demands have been set on the higher energy storage density as well as better temperature resistance for dielectric polymers. Up to now, hierarchical structure provides an effective way to meet these requirements. Herein, we report a sandwich-structured all-organic composite via inserting polymethyl methacrylate/poly(vinylidene fluoride) (PMMA/PVDF) blend layer into polyetherimide layers. Increasing temperature increases the permittivity of the middle layer and the addition of PMMA makes the permittivity increase faster with temperature than pure PVDF middle layer. The capacitor series model and finite element simulation confirmed that the change of the middle layer permittivity realized the electric field redistribution to self-adapt to the temperature, preventing premature breakdown at elevated temperature. At 100 °C, optimized composite exhibits a high breakdown strength of 486.05 MV/m along with high polarization. Eventually, a high discharge energy density of 8.65 J/cm3 is obtained, which is 229.44% of pure PEI. The high polarization at high temperature was realized by utilizing the permittivity of PMMA/PVDF rising with temperature, thereby increasing the energy density at elevated temperature.

Battery Electric Vehicles Energy Consumption Breakdown from On-Road Trips <xref rid="FN_1" ref-type="fn"><sup>1</sup></xref>

<div class="section abstract"><div class="htmlview paragraph">Battery Electric Vehicle (BEV) sales have been spiking up due to a series of factors: zero tailpipe emissions, wider model availability, increased customer acceptance, reduced purchase price, improved performance and range. The latter is a crucial factor the consumers consider when purchasing a BEV, and it largely depends on how the vehicle operates (e.g. average speed), traffic, ambient conditions, and battery size. When driven on the roads, the actual range of BEVs can be significantly smaller than the certified value obtained from laboratory testing at standard conditions. To understand the factors influencing vehicle range in real-world operation, the study team performed on-road tests on three production passenger vehicles currently available in the European market. The measured quantities, including vehicle signals from OBD/UDS, were used to quantify the vehicle energy consumption. Global Navigation Satellite System (GNSS) data was used to calculate vehicle positioning and resistances, including altitude. Findings show an average consumption of 201.5 Wh/km for mid-sized passenger cars, ranging between 150 to 293.4 Wh/km (minimum and maximum observed values from a B-Segment vehicle and a 9-Seater VAN, respectively). Ambient temperature is one of the factors introducing a high variability in real-world energy consumption, as electric energy is used both for cabin heating and cooling, which might lead to range reductions of 30-50 % under extreme conditions. An energy breakdown is presented for each trip, describing the typical share of propulsion, cooling/heating needs and other auxiliaries.</div></div>

Achieving high energy storage performance and breakdown strength in modified strontium titanate ceramics

Achieving high energy storage performance and breakdown strength in modified strontium titanate ceramics

THE PRESENCE OF ANTIOXIDANTS IN THE HAIR INFUNDIBULUM IMPLICATIONS IN HAIR DISEASES SUCH AS ALOPECIA

Anatomically, as a rule the hairs in mammals consists of an unseen follicle or root anchored into the skin with a shaft or visible hair exiting exteriorly. As a note of interest, the hair follicle has been described as a miniorgan having its own cells division, metabolism and aging stages (1). As previously stated “metabolism entails electron transfers in both plants (photosynthesis) and animals (cellular respiration) involving movement of electrons from donor to acceptor along the electron transfer chain thus inducing a current within each cell and from cell to cell” (2,3). This continuity of energy transfer in living organisms is at the very essence of life; and is ubiquitously present in all living matter and the generator of Bioelectricity (a.k.a. electromagnetic radiation), the protein enzyme catalase having an essential pivotal role in energy production in the breakdown of toxic materials such as H2O2 into H2O and O2 molecules. During the breakdown of O2 molecules energy is generated. When catalase is depleted life ends and regional death occurs (4,5). We could then theorize that if cell respiration ceases throughout the entire organism (organs) death ensues (6). Only in living tissue is that elimination of toxic material such as H2O2 has any relevance.

Breakdown Strength and Energy Density Improvement of Polypropylene by Parylene Deposition for Film Capacitor

In this article, a surface modification method is proposed for improving the breakdown strength and the energy density of polypropylene (PP) films for power capacitors based on chemical vapor deposition (CVD). The results indicate that after 5% thickness deposition, the leakage conductivity of the composite films decreases by 77% at 30 °C and declines by 96.2% at 85 °C compared with the pristine PP samples. The dielectric constant is increased from 2.19 to 2.34 at 1 kHz. The dielectric loss decreases from 0.0425 to 0.0047. The dc breakdown strength is enhanced from 553.7 to 658.5 kV/mm, and the energy density is improved by 40%–50%. The parylene deposition successfully increases the withstand voltage and the energy density by inhibiting charge injection. The results provide a reference for optimizing the performance of capacitor by interface modification.

Enhanced energy storage performance of all-organic sandwich structured dielectrics with FPE and P(VDF-HFP)

Rational design of multilayer structures can greatly improve the breakdown strength and is thus an effective method to improve the energy density of all-organic polymers. In this paper, a simple hot-pressing method was used to combine P(VDF-HFP) with FPE to prepare an all-organic multi-layered composite film with a symmetric structure. The effects of the sandwich structure on the breakdown strength, dielectric properties, and energy storage properties of multilayer materials were investigated in depth. Compared with the single-layer P(VDF-HFP), the FPE on both sides of the composite significantly enhanced the breakdown strength and inhibited the dielectric loss. In particular, when the multi-layer structure composite film with intermediate layer P (VDF-HFP) thickness of 6 μm, the energy storage density and energy storage efficiency reach 11.0 J/cm3 and 86.7%, respectively, realizing double-improvement. This work can provide reliable theoretical analysis and experimental guidance for the preparation of high-performance flexible all-organic dielectrics.

Enhanced breakdown strength and energy density by introducing low-loading poly(1,5-anthraquinone) into poly(vinylidene fluoride)

Enhanced breakdown strength and energy density by introducing low-loading poly(1,5-anthraquinone) into poly(vinylidene fluoride)

Cold plasma processing improved the extraction of xylooligosaccharides from dietary fibers of rice and corn bran with enhanced in-vitro digestibility and anti-inflammatory responses

Here, the impact of cold plasma on extraction of xylooligosaccharides (XOS) from rice and corn bran dietary fibers was investigated. Prior to extraction of XOS, polyphenol and dietary fibers were separated from rice and corn bran. Upon cold plasma, the observed changes in the structure of rice and corn bran dietary fibers through FTIR analysis documented their suitability for XOS extraction. Cold plasma treatment was observed to significantly (p < 0.05) improve the extraction of XOS from rice and corn bran dietary fibers as compared to untreated. Moreover, SEM images showed micro-punctures in rice and corn bran dietary fibers upon cold plasma treatment. Furthermore, XOS extracted through cold plasma treatment showed better gastric digestion. Also, the cold plasma extracted XOS showed no cytotoxicity against RAW 264.7 and HepG2 cell lines. Cold plasma extracted XOS were observed to improve the anti-inflammatory responses. Industrial relevancyNow-a-days, fast pace lifestyle demands attention for extraction of nutraceutical compounds like XOS and resource utilization of industrial biomass for extraction of value-added products is need of the hour. Industries are trying to extract these value-added biomolecules but the procedure of extracting these compounds is expensive as well as extensive. Therefore, there is need of powerful and clean technology for extracting such compounds. Cold plasma is one of such technologies which consumes very less energy for efficient breakdown of cell walls to release their valuable compounds. In this regard, present study documented the use of cold plasma processing in the extraction of XOS, useful prebiotics from the industrial by-products rice and corn bran. Hence, the technology documented the utilization of industrial waste biomass for the efficient recovery of XOS with better qualities.

Enhancing high-temperature capacitor performance of polymer nanocomposites by adjusting the energy level structure in the micro-/meso-scopic interface region

The interface plays a major role in the conduction and breakdown behaviors of dielectric materials. Enhancing interface compatibility and Schottky barrier to reduce conduction loss and enhance breakdown strength of nanocomposites has been widely studied. Nevertheless, there are few reports on the effect of the energy level structure in filler/polymer and electrode/dielectric interface region on the breakdown strength and high-temperature energy storage performances. Herein, the polyimide (PI) films sandwiched by Al2O3 layers and filled with SiO2 shell-coated high-K BaTiO3 nanofibers were prepared. Our results reveal that the wide bandgap oxide layer can regulate the energy level structure of the interface region, introduce deep traps in the nanocomposites and increase the Schottky barrier at the electrode/dielectric interface to impede charge injection and transport. Moreover, the nanocomposites combine the advantages of anisotropic dielectric properties from the Al2O3 layer, SiO2 shell, and BaTiO3 core, enhancing dielectric constants of the nanocomposites. The optimal nanocomposites show greatly enhanced discharge energy density and breakdown strength at 150 °C, which are 370% and 38% higher than those of PI, respectively. This work provides more insight into the mechanism of electrical conduction and breakdown in polymer nanocomposites and offers an effective strategy for developing polymer nanocomposites with superior capacitive performance at elevated temperatures.