High energy storage performances of P(VDF-HFP)-based nanocomposites by dual-filler synergy of carbon quantum dots and Ni(OH)2 nanosheets

Manipulating fluorine induced bulky dipoles and their strong interaction to achieve high efficiency electric energy storage performance in polymer dielectrics

Glass ceramics are supposed to offer the potential of retaining the high permittivity of ceramics, and at the same time exhibiting high dielectric breakdown strength (DBS), thus producing high dielectric energy storage performance in bulk material. Nonetheless, to date, it still remains a big challenge to achieve high energy storage density in glass ceramics compared to other dielectric energy storage materials. Herein, we conceived and fabricated a new type of BaTiO3-based glass ceramics with nanoscale polymorphic structure in a single nano-grain formed by Ge-ions simultaneous substitution of A and B sites during crystallization. It has been found that appropriate GeO2 doping concentration will form nanoscale spontaneous polarization vortex domains in a single nano-grain, which enhances polarization, efficiency, and DBS. As a result, excellent energy storage performance is achieved, with a high recoverable energy density (Wrec) of 10.08 J cm-3 with high energy storage efficiency of 91.3% and high charge-discharge energy storage density (Wd) of 8.84 J cm-3 under 1500kV cm-1. It also exhibits ultrahigh hardness (10.2GPa). This work shows the potential applications of BaTiO3-based glass ceramics in high and pulsed power devices and provides a strategy for designing advanced dielectric glass ceramics.

Dielectric capacitors with high energy storage performance are in great demand for emerging advanced energy storage applications. Relaxor ferroelectrics are one type dielectric materials possessing high energy storage density and energy efficiency simultaneously. In this study, 0.9(Sr 0.7 Bi 0.2 )TiO 3 –0.1Bi(Mg 0.5 Me 0.5 )O 3 (Me = Ti, Zr, and Hf) dielectric relaxors are designed and the corresponding energy storage properties are investigated. The excellent recoverable energy density of 3.1 J/cm 3 with a high energy efficiency of 93% is achieved at applied electric field of 360 kV/cm for 0.9(Sr 0.7 Bi 0.2 )TiO 3 –0.1Bi(Mg 0.5 Hf 0.5 )O 3 (0.9SBT–0.1BMH) ceramic. High breakdown strength of 460 kV/cm in 0.9SBT–0.1BMH ceramic is obtained by Weibull distribution with satisfied reliability. In addition, 0.9SBT–0.1BMH shows outstanding thermal stability of energy storage performance up to 200°C, with the variation being less than 5%, together with satisfying cycling stability and high charge‐discharge rate, making the 0.9SBT–0.1BMH ceramic a potential lead‐free candidate for high power energy storage applications at elevated temperature.

Ni-modified BaTiO3 film prepared by sol-gel with high energy storage performance

High temperature electrical breakdown and energy storage performance improved by hindering molecular motion in polyetherimide nanocomposites

(Bi0.5Na0.5)TiO3-based relaxor ferroelectrics with simultaneous high energy storage properties and remarkable charge-discharge performances under low working electric fields for dielectric capacitor applications

The compromise of contradictive parameters, polarization, and breakdown strength, is necessary to achieve a high energy storage performance. The two can be tuned, regardless of material types, by controlling microstructures: amorphous states possess higher breakdown strength, while crystalline states have larger polarization. However, how to achieve a balance of amorphous and crystalline phases requires systematic and quantitative investigations. Herein, the trade-off between polarization and breakdown field is comprehensively evaluated with the evolution of microstructure, i.e., grain size and crystallinity, by phase-field simulations. The results indicate small grain size (≈10-35nm) with moderate crystallinity (≈60-80%) is more beneficial to maintain relatively high polarization and breakdown field simultaneously, consequently contributing to a high overall energy storage performance. Experimentally, therefore an ultrahigh energy density of 131 J cm-3 is achieved with a high efficiency of 81.6% in the microcrystal-amorphous dual-phase Bi3NdTi4O12 films. This work provides a guidance to substantially enhance dielectric energy storage by a simple and effective microstructure design.

Design strategy of high-entropy perovskite energy-storage ceramics: A review

The development of lead-free dielectric capacitors capable of reliable operation across extreme temperatures is crucial for next-generation energy storage technologies. While relaxor ferroelectrics below the Burns temperature (TB) have demonstrated promising energy storage characteristics via polar nanoregions (PNRs), their performance typically deteriorates above TB. Surprisingly, a trirelaxor-a state composed of PNRs is reported with three coexisting symmetries (tetragonal, orthorhombic, and rhombohedral)-that exhibits high energy storage performance in the paraelectric state aboveTB. In lead-free Bi(Mg2/3Nb1/3)O3-doped Ba(Zr,Ti)O3-(Ba,Ca)TiO3 perovskite ceramics, the trirelaxor aboveTB achieves a remarkable energy storage density of 9.3 Jcm-3and an efficiency of 93%, which is comparable to the performance of other lead-free dielectrics measured belowTB. More importantly, the high energy storage properties of trirelaxor above TB enable the material to exhibit excellent comprehensive energy storage performance over a broad operating temperature range of -90 to 200°C, which outperforms existing lead-free perovskite dielectric materials. This work provides new insights into developing desirable energy-storage dielectrics with high energy storage performance over an extended operating temperature range.

With the development of science and technology, polymer dielectric capacitors are widely used in energy, electronics, transportation, aerospace, and many other areas. For polymer dielectric energy storage capacitors to remain effective in practical applications, excellent charge and discharge performance is essential. However, the performance of the common polymer dielectric capacitors will deteriorate rapidly at high temperature, which makes them fail to work efficiently under worse working conditions. Dielectric trap energy levels and trap densities increase when nanoparticles are incorporated into the dielectric. The change in trap parameters will affect carrier transport. Therefore, the high temperature energy storage performance of polymer nanocomposite dielectric can be improved by changing the trap parameters to regulate the carrier transport process. However, the quantitative relationship between trap energy level and trap density and the energy storage properties of nanocomposite dielectric need further studying. In this paper, the energy storage and release model for exponentially distributed trapped charge jump transport in linear polymer nanocomposite dielectrics is constructed and simulated. The volume resistivity and electric displacement-electric field loops of pure polyetherimide are simulated at 150 ℃, and the simulation results match the experimental results, which demonstrates the validity of the model. Following that, under different temperatures and electric fields, the current density, electric displacement-electric field loops, discharge energy density and charge-discharge efficiency of polyetherimide nanocomposite dielectric are simulated by using different trap parameters. The results show that increasing the maximum trap energy level and the total trap density can effectively reduce the carrier mobility, current density and conductivity loss, and enhance the discharge energy density and the charge-discharge efficiency of the nanocomposite dielectric. On condition that temperature is 150 ℃ and applied electric field is 550 kV/mm, the polyetherimide nanocomposite dielectric with a maximum trap energy level of 1.0 eV and a total trap density of 1×10<sup>27</sup> m<sup>–3</sup>, has 4.26 Jcm<sup>–3</sup> of discharge energy density and 98.93% of energy efficiency. These parameters in the polyetherimide nanocomposite dielectric are 91.09% and 227.58% higher than those in the pure polyetherimide, respectively. The energy storage performance under high temperature and high electric field is obviously improved. It provides theoretical and model support for the research and development of capacitors with high temperature resistance and energy storage performance.

With the development of science and technology, polymer dielectric capacitors are widely used in energy, electronics, transportation, aerospace, and many other areas. For polymer dielectric energy storage capacitors to remain effective in practical applications, excellent charge and discharge performance is essential. However, the performance of the common polymer dielectric capacitors will deteriorate rapidly at high temperature, which makes them fail to work efficiently under worse working conditions. Dielectric trap energy levels and trap densities increase when nanoparticles are incorporated into the dielectric. The change in trap parameters will affect carrier transport. Therefore, the high temperature energy storage performance of polymer nanocomposite dielectric can be improved by changing the trap parameters to regulate the carrier transport process. However, the quantitative relationship between trap energy level and trap density and the energy storage properties of nanocomposite dielectric need further studying. In this paper, the energy storage and release model for exponentially distributed trapped charge jump transport in linear polymer nanocomposite dielectrics is constructed and simulated. The volume resistivity and electric displacement-electric field loops of pure polyetherimide are simulated at 150 ℃, and the simulation results match the experimental results, which demonstrates the validity of the model. Following that, under different temperatures and electric fields, the current density, electric displacement-electric field loops, discharge energy density and charge-discharge efficiency of polyetherimide nanocomposite dielectric are simulated by using different trap parameters. The results show that increasing the maximum trap energy level and the total trap density can effectively reduce the carrier mobility, current density and conductivity loss, and enhance the discharge energy density and the charge-discharge efficiency of the nanocomposite dielectric. On condition that temperature is 150 ℃ and applied electric field is 550 kV/mm, the polyetherimide nanocomposite dielectric with a maximum trap energy level of 1.0 eV and a total trap density of 1×10<sup>27</sup> m<sup>–3</sup>, has 4.26 J·cm<sup>–3</sup> of discharge energy density and 98.93% of energy efficiency. Compared with pure polyetherimide, the rate of improvement is 91.09% and 227.58%, respectively. The energy storage performance under high temperature and high electric field is obviously improved. It provides theoretical and model support for the research and development of capacitors with high temperature resistance and energy storage performance.

We report a distinctive way for designing lead-free films with high energy storage performance. By inserting different single perovskite cells into Bi4Ti3O12, P–E hysteresis loops present larger maximum polarization, higher breakdown strength and smaller slim-shaped area. We prepared 0.15Bi7Fe3Ti3O21-0.5Bi4Sr3Ti6O21-0.35Bi4Ba3Ti6O21 solid solution ferroelectric films employing the sol-gel method, and obtained high energy storage density of 132.5 J/cm3 and efficiency of 78.6% while maintaining large maximum polarization of 112.3 μC/cm2 and a high breakdown electric field of 3700 kV/cm. Moreover, the energy storage density and efficiency exhibit stability over the temperature range from 20 °C to 125 °C, and anti-fatigue stability maintains up to 108 cycles. The films with a simple preparation method and high energy storage performance are likely to become candidates for high-performance energy storage materials.

Lead-free relaxor ferroelectric ceramics with high recoverable energy storage density and energy storage efficiency over a broad temperature and frequency range are attractive for pulsed power capacitor applications. In this work, novel barium zirconate titanate-based lead-free relaxor ferroelectric ceramics are designed via introduction of Bi(Zn0.5Sn0.5)O3 with heterovalent ion substitution at both A- and B-sites which could disrupt long-range order, induce polar nanoregions (PNRs), and reduce remnant polarization (Pr). The (1 − x)Ba(Zr0.15Ti0.85)O3–xBi(Zn0.5Sn0.5)O3 ((1 − x)BZT–xBZS) (x = 0.02, 0.06, 0.10, and 0.14) ceramics were prepared using a conventional solid-state reaction method. In addition, the structure, dielectric, ferroelectric, and energy storage properties of (1 − x)BZT–xBZS ceramics were systematically studied. All (1 − x)BZT–xBZS ceramics exhibited pure perovskite structure. With the increase of BZS content, the relaxor ferroelectric feature of (1 − x)BZT–xBZS ceramics tended to increase gradually, and slim linear P–E loops were obtained in x = 0.10–0.14. A high recoverable energy storage density Wrec of 2.16 J/cm3 and a high energy storage efficiency η of 90.3% were simultaneously achieved in x = 0.10 at 250 kV/cm, together with excellent temperature and frequency stability, which were superior to those of the reported barium zirconate titanate-based ceramics. Our work provides an effective strategy to optimize the energy storage performance of lead-free barium zirconate titanate-based ceramics toward practical applications.

With the development of power electronic device equipment towards miniaturization and high performance, the dielectric materials with high energy storage density, high charge and discharge efficiency, easy processing and molding, and stable performance are urgently needed. At present, Barium titanate-based dielectric ceramics have a high dielectric constant, but low breakdown field strength and poor flexibility. Polymer-based dielectric materials have ultra-high functional density, ultra-fast charge and discharge response time, good flexibility, high breakdown field strength, light weight and other advantages, but low dielectric constant and low polarization strength. Their energy storage density is low, which limits the power capacitor component size and application scope. In order to obtain material with high energy storage performance, it was proposed to add high dielectric constant inorganic ceramic fillers to the polymer through a composite method to improve the energy storage performance of the material. The interface plays a vital role in the performance of the composite material. In this article, we review the latest research advance in the interface design and control of barium titanate/polyvinylidene fluoride composite dielectric materials. The effects of interface modification methods such as organic surface modification, inorganic functionalization and organic-inorganic synergistic modification on the polarization and energy storage performance of composite materials are summarized. The existing interface models and theoretical research methods are discussed, and the existing challenges and practical limitations, and the future research directions are prospected.

Achieving high energy storage performance in PbHfO3-based antiferroelectric ceramics by Sr element doping