Enhanced Energy Storage Density Research Articles

Improved electrical properties in PZT/PZ thin films by adjusting annealing temperature

In this study, PbZr0.52Ti0.48O3/PbZrO3 (PZT/PZ) multilayer films were prepared on SiO2/Si substrate buffered with LaNiO3 (LNO) thin films, and then annealed at different temperatures by rapid thermal annealing (RTA) technology. The phase structures, microstructures, and electrical properties of the obtained PZT/PZ multilayer films were studied. According to the results of XRD and SEM, it was found that the PZ films with perovskite phase were obtained by annealing at 650 °C firstly. The PZT films on crystallized PZ films were in amorphous phase after annealing at 450 °C, in pyrochlore phase after annealing at 550 °C, and finally in perovskite phase at annealing temperature higher than 600 °C. The multilayer films with the PZT films annealed at 550 °C exhibited linear hysteresis loops, and such films showed the enhanced energy storage density of 31.6 J cm−3 and the energy storage efficiency of 66.9% at a high breakdown field strength of 2475 kV cm−1. The experimental results proved that the phase structure of the PZT/PZ multilayer films can be regulated by different annealing temperatures, which could further enhance the energy storage performance of the PZT/PZ multilayer films.

Enhanced energy storage density of Bi3.25La0.75Ti3O12 thin films by preferred orientation and interface engineering

Dielectric energy storage capacitors are promising avenues for high power density and fast charge/discharge applications. This study focused on the deposition of Bi3.25La0.75Ti3O12 (BLT) films onto Pt/Ti/SiO2/Si substrates by a sol-gel technology. Through the synergistic strategy of interface engineering and the preferred orientation of BLT film, the residual polarization was minimized, and the breakdown field strength was enhanced. As a result, the recoverable energy density (Urec) was significantly improved to 62.97 J/cm3 with a high energy storage efficiency (η) of 85.88 %. Notably, the synthesized BLT film exhibited excellent temperature (25–150 °C) and frequency (100 Hz-10 kHz) stability of Urec (>30 J/cm3) and η (>75 %) at ∼2200 kV/cm. The finding demonstrates the potential of BLT thin film as a lead-free material for the next generation of pulse power capacitors. Overall, the synergistic approach of interface engineering and preferred orientation proves to be an effective way to improve the performance of dielectric energy storage capacitors.

Enhanced energy-storage density in (Pb0.98La0.02)(Zr0.45-xSn0.55Hfx)0.995O3 antiferroelectric ceramics

Antiferroelectric ceramics with unique characteristics of electric-field-induced antiferroelectric to ferroelectric phase transitions and ultra-fast charging-discharging rate, which are demanded in high pulse power devices. In this work, (Pb0.98La0.02)(Zr0.45-xSn0.55Hfx)0.995O3 (PLZSH) antiferroelectric ceramics with x = 0∼0.20 were prepared via a conventional solid-state reaction approach. Incommensurate modulation structure with a 1/n<110> superlattice was observed in AFE at room temperature, which was associated with the unique domain boundaries, contributing the obvious declined AFE-FE phase transition electric field as well as the enhanced energy storage density. It was also observed that the maximum recoverable energy storage density (Wrec) increases from 2.93 J/cm3 (x = 0) to 5.72 J/cm3 (x = 0.15), and the corresponding energy-storage efficiency uprises from 82.4 % to 87.8 % with the increasing x at 280 kV/cm. The superior energy density and efficiency indicate that the obtained PLZSH antiferroelectric ceramics are promising for practical applications in pulse power devices.

Solid-solid phase change fibers with enhanced energy storage density for temperature management

Solid-solid phase change fibers are advantageous for thermal management and latent heat storage, because they don't have the issue of liquid leakage facing those common ones that have a solid-liquid phase-transition. However, the relatively low heat density hinders such fibers from real applications. Herein, we report a strategy to fabricate solid-solid phase change fibers with much enhanced energy storage density, through coaxial wet spinning using thermoplastic polyurethane solution and polymerizable polyethylene glycol solution as outer spinning solution and inner spinning solution, respectively, followed by light-driven radical polymerization. The resulting fibers exhibited good flexibility and good tensile performances, with elongation at break and breaking strength of approximately 629.1 % and 3.8 MPa, respectively. Moreover, the fibers showed quite high heat density of 122.5 J/g, much higher than that of the previously reported phase change fibers with a solid-solid phase-transition, and high reusability, with heat density of 102.0 J/g preserved after 100 heating-cooling cycles. These attractive features make the fibers to be promising for wearable temperature management, energy harvesting and heat storage applications.

Enhanced Energy Storage Density of Ferroelectric Polymer-Based Composite Dielectrics via Introducing Surface-Charged Kaolin Nanosheets

Enhanced Energy Storage Density of Ferroelectric Polymer-Based Composite Dielectrics via Introducing Surface-Charged Kaolin Nanosheets

Improved energy density and efficiency of polymer nanocomposites by filling ultralow amounts of 2D Ni(OH)2 nanosheets and building sandwich structure

Currently, the application of polymer dielectric capacitors is largely limited by their low energy storage density. Herein, novel sandwich-structured composite films with simultaneously enhanced energy storage density and efficiency are fabricated, which combine outer layers of inorganic nanosheets Ni(OH)2/poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) with high permittivity and intermediate layer of polycarbonate (PC) with high breakdown strength. The trilayer film with only 1 vol% Ni(OH)2 exhibits an excellent energy storage density of 7.322 J/cm3 accompanied with a high efficiency of 72.1 % at 605 kV/mm, which are 120 % and 113 % of pure P(VDF-HFP). Furthermore, hindrance effect of micro-interfaces and macroscopical-interfaces on electrical trees is well revealed through finite element simulation. These excellent characteristics of composite films suggest that this design strategy is effective to realize concurrent high energy density and efficiency.

High-entropy (Na0.2Bi0.2Ba0.2Sr0.2Zn0.2)TiO3 ceramics with enhanced energy storage density and reliable stability

High-entropy ceramics (HECs) have gained increasingly recent interest due to their fantastic physiochemical properties and rich compositions. The investigation of energy storage performance based on the temperature and frequency stability of HECs is still at an early stage, with limited reported studies. Here, we report lead-free (Na0.2Bi0.2Ba0.2Sr0.2Zn0.2)TiO3 (NBBSZT) HECs by a solid-state approach with a pressureless sintering process. X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies demonstrate that NBBSZT HECs show a pure perovskite structure, uniform morphology and element distribution. Ferroelectric measurements indicate that the NBBSZT HECs exhibit an improved energy storage density of 1.03 J/cm3 and an efficiency of 77%, which is approximately 5 times and 17 times enhancement compared to Bi0.5Na0.5TiO3 (BNT) ceramics, respectively. The NBBSZT HECs also demonstrate excellent thermal stability and satisfactory frequency stability. More interestingly, the dielectric property studies show that the NBBSZT HECs exhibit frequency dispersion and diffuse phase transition. Temperature-dependent dielectric measurements indicate that the NBBSZT HECs exhibit better relaxor characteristics than that of BNT ceramics. These studies reveal that the high-entropy strategy provides a potential platform for designing ferroelectric ceramics.

Significantly enhanced energy storage density and efficiency of sandwich polymer-based composite via doped MgO and TiO2 nanofillers

Significantly enhanced energy storage density and efficiency of sandwich polymer-based composite via doped MgO and TiO2 nanofillers

Influence of NaNbO3 addition to Bi0.5(Na0.8K0.2)0.5TiO3 lead-free ceramics on the energy storage properties

(1-x)Bi0·5(Na0·8K0.2)0.5TiO3/xNaNbO3 (x = 0–0.1) ceramics are prepared through solid-state reaction. The incorporation of NaNbO3 leads to slight crystal distortion with nanoscale particle size, improving the relaxor phenomenon by destruction of the original ferroelectric long-range order, which finally contributes to the enhanced energy storage density and efficiency. Particularly, the outstanding energy storage properties are observed at x = 0.075 with well thermal, frequency and cycle stability. Moreover, the highest energy storage density and efficiency are obtained at ∼160 °C with x = 0.075. Further, the well charge-discharge performance is also achieved. These results indicate that designing Bi0·5(Na0·8K0.2)0.5TiO3-based relaxor ferroelectrics through NaNbO3 is an effective method to realize excellent energy storage performance in dielectric capacitors.

Enhancement of the dielectric energy storage performance of PVDF‐TrFE composite film via core‐shell structured (1‐x)Ba(Ti0.8Zr0.2)O3‐x(Ba0.7Ca0.3)TiO3@TiO2

AbstractPVDF‐based materials have gained significant attention in the field of dielectric energy storage due to their excellent breakdown strength and energy storage density. However, the improvement has been limited by their low dielectric constant. In this article, the PVDF‐TrFE composite films with core‐shell structured (1‐x)Ba(Ti0.8Zr0.2)O3‐x(Ba0.7Ca0.3)TiO3@TiO2(BZT‐xBCT@TiO2) nanofibers were fabricated using hot pressing, electrospinning, and hydrothermal method. Doping the PVDF‐TrFE composite film with 3 wt% BZT‐0.6BCT increased its energy storage density to 14.2 J·cm−3. When the doped ceramic fibers were coated with the TiO2 core‐shell of ~75 nm, the composite film exhibits improved breakdown field strength (Eb) of 365 kV mm−1, enhanced energy storage density (Ue) of 18.71 J·cm−3, and superior energy storage efficiency (η) of 60.03%.

Potassium sodium niobate-based transparent ceramics with high piezoelectricity and enhanced energy storage density

Lead-free potassium sodium niobate (KNN)-based transparent ceramics are highly desirable owing to their excellent piezoelectricity, and recoverable energy storage density (Wrec) especially for optoelectronic devices. However, it is challenging to achieve all parameters such as efficient light transmittance and excellent piezoelectricity or energy storage performance in a single device. Herein, we report a facile fabrication of transparent ceramic composed of (1 – x)[(Na0.57K0.43)0.94Li0.06][(Nb0.94Sb0.06)0.95Ta0.05]O3-xCaZrO3 (x = 0, 0.01, 0.03, 0.05, 0.07, 0.09 and 0.10) ((1 – x)KNLNST-xCZ) via conventional solid-state reaction method. It has been found that ceramics can retain good light transmission and maintain their piezoelectric properties by adjusting the phase structure and refining the grains to a certain extent. In particular, KNLNST-based transparent ceramic with 0.07CZ modifications demonstrates a high transmittance (T = 73.5% at 1800 nm) and exceptional piezoelectric constants (d33 = 130 pC/N), which is more efficient than reported KNN-based transparent ceramics. More importantly, a significant improvement in grain size refinement is also achieved through the integration of CZ into KNLNST, which allow us to increase the breakdown strength of the ceramics while improving their light transmittance, which result in a high density of energy storage. The highly efficient energy storage performance (Wrec = 4.88 J/cm3) and the higher transparency (T = 75% at 1800 nm) at 0.91KNLNST-0.09CZ ceramic. We believe that this work will provide useful strategies for the development of KNN-based functional ceramics.

Greatly enhanced energy storage density of alkali-free glass-ceramics after dual optimizations by thickness and crystallization temperature

Glass-ceramics show a great application potential in sustainable development, environmental protection, high temperature, high voltage resistance, and so on. Given the breakdown strength has a great contribution to the energy storage density, alkali-free niobate-based glass-ceramics have emerged as a prominent energy storage material. In this study, the 13.64BaCO3-13.64SrCO3-32.72Nb2O5-40SiO2 alkali-free glass-ceramics were optimized in thickness and crystallization temperature. The thinning of thickness improves the breakdown strength. At the same time, the dielectric constant gets a maximum value by adjusting the crystallization temperature. Therefore, an ultra-high theoretical energy storage density of 27.47 J·cm−3 is obtained. In addition, the finite element software simulates the electric field distribution and electric potential evolution during the development of electric branches, which illustrates the role of glass phase in hindering the development of electric branches and partaking the high electric field. Finally, the effective energy storage density obtained by using P-E loops is 1.49 J·cm−3 under 850 kV/cm.

Enhanced energy storage density and efficiency in La(Mg2/3Ta1/3)O3-doped BiFeO3 based ceramics

High-performance dielectric capacitor materials are required for the miniaturization of electronic devices. To this end, (1-x)(0.65BiFeO3-0.35BaTiO3)-xLa(Mg2/3Ta1/3)O3 (BFBT-xLMT, x = 0, 0.06,0.10, 0.14 and 0.18) ceramics were fabricated by a solid-state method. The experimental results indicate that LMT doping can well improve the energy storage density (Wrec) and efficiency (η) of BFBT ceramics. Especially, the optimal energy storage performance (ESP) (Wrec=4.92 J/cm3, η = 85%) was obtained in BFBT-0.14LMT ceramics under 390 kV/cm. The enhancement of ESP of BFBT-0.14LMT ceramics can be ascribed to the decreased hysteresis of polarization (P) - electric field (E) loops resulting from the aggravation of the composition and charge disorder in the system, and the improved breakdown strength (Eb) which is related to the reduced grain size, the widened band gap (Eg) and the decreased oxygen vacancy concentration. Additionally, the thermal stability of ESP of BFBT-0.14LMT ceramics is also enhanced compared with pure BFBT ceramics. Meanwhile, BFBT-0.14LMT ceramics exhibit a fast discharge rate (t0.9 = 152 ns) under 180 kV/cm. These results indicate that BFBT-0.14LMT ceramics could be a promising dielectric capacitor material. In general, our study reveals that LMT is good dopant to enhance the Eb and ESP of BF-based ceramics.

Tripling energy storage density through order–disorder transition induced polar nanoregions in PbZrO3 thin films by ion implantation

Dielectric capacitors are widely used in pulsed power electronic devices due to their ultrahigh power densities and extremely fast charge/discharge speed. To achieve enhanced energy storage density, maximum polarization (Pmax) and breakdown strength (Eb) need to be improved simultaneously. However, these two key parameters are inversely correlated. In this study, order–disorder transition induced polar nanoregions have been achieved in PbZrO3 thin films by making use of the low-energy ion implantation, enabling us to overcome the trade-off between high polarizability and breakdown strength, which leads to the tripling of the energy storage density from 20.5 to 62.3 J/cm3 as well as the great enhancement of breakdown strength. This approach could be extended to other dielectric oxides to improve the energy storage performance, providing a new pathway for tailoring the oxide functionalities.

Significantly enhanced energy storage density in lead-free barium strontium titanate-based ceramics through a cooperative optimization strategy

An ultrahigh Wrec of 5.53 J cm−3 (460 kV cm−1) has been achieved in the 0.91BST–0.09BZT ceramic, together with good temperature stability at 200 kV cm−1 and excellent fatigue resistance.

Fabrication of a lead-free ternary ceramic system for high energy storage applications in dielectric capacitors.

The importance of electroceramics is well-recognized in applications of high energy storage density of dielectric ceramic capacitors. Despite the excellent properties, lead-free alternatives are highly desirous owing to their environmental friendliness for energy storage applications. Herein, we provide a facile synthesis of lead-free ferroelectric ceramic perovskite material demonstrating enhanced energy storage density. The ceramic material with a series of composition (1-z) (0.94Na0.5Bi0.5TiO3-0.06BaTiO3)-zNd0.33NbO3, denoted as NBT-BT-zNN, where, z = 0.00, 0.02, 0.04, 0.06, and 0.08 are synthesized by the conventional solid-state mix oxide route. Microphases, microstructures, and energy storage characteristics of the as-synthesized ceramic compositions were determined by advanced ceramic techniques. Powder X-ray diffraction analysis reveals pure single perovskite phases for z = 0 and 0.02, and secondary phases of Bi2Ti2O7 appeared for z = 0.04 and 0.08. Furthermore, scanning electron microscopy analysis demonstrates packed-shaped microstructures with a reduced grain size for these ceramic compositions. The coercive field (Ec) and remnant polarization (Pr) deduced from polarization vs. electric field hysteresis loops determined using an LCR meter demonstrate decreasing trends with the increasing z content for each composition. Consequently, the maximum energy storage density of 3.2J/cm3, the recoverable stored energy of 2.01J/cm3, and the efficiency of 62.5% were obtained for the z content of 2mol% at an applied electric field of 250kV/cm. This work demonstrates important development in ceramic perovskite for high power energy storage density and efficiency in dielectric capacitors in high-temperature environments. The aforementioned method makes it feasible to modify a binary ceramic composition into a ternary system with highly enhanced energy storage characteristics by incorporating rare earth metals with transition metal oxides in appropriate proportions.

Ferroelectric Ceramic Materials Prepared by Nanoparticles in Outdoor Environmental Sculpture Art

With the development and progress of the city, people’s research on outdoor sculpture has gone deeper, and the field of material research has been raised to the field of spiritual culture. Tang Sancai is beautiful in color and wonderful in shape, such that when ceramics are used in outdoor environmental sculpture art, except for its performance, its appearance and tone must also be taken into consideration. Even when ferroelectric ceramics are used in outdoor sculptures, changing their shapes and taking into account their colors can be done invisibly only by passing through an electromagnetic field. Ferroelectric ceramics are generally divided into insulating, dielectric, piezoelectric, magnetic, semiconductor, transparent, and infrared sensor ceramics. This article integrates the manufacturing method of ferroelectric ceramics into outdoor environmental sculpture art. First of all, this article describes the ferroelectric ceramics and outdoor environmental sculptures, explains the method of preparing ferroelectric ceramics from barium titanate nanoparticles, and explains the pyroelectric inverse process of the electric card effect principle of electric ceramic materials, the thermodynamics of Maxwell’s relationship, and the thermodynamics of Landau’s phenomenological theory. The elasticity of the system is calculated, and the preparation of tetragonal barium titanate ferroelectric ceramics prepared by hydrothermal nanoparticles and SBT/Cu ferroelectric ceramic composites prepared by nanoparticle metallurgy is explained. In the plasma discharge mode, the optimal temperature for sintering the composite material is obtained. Then through experiments, research on the preparation and performance of the high dielectric constant BTnf-Ag/PVDF ferroelectric ceramic nanocomposite and its application in environmental sculptures are demonstrated. Compared with the two ancient BTnf/PVDF composite materials, the barium titanate fiber prepared by electrostatic spinning shows that the BTnf-Ag/PVDF composite material has a higher dielectric constant, and the dielectric loss is not too high. The 41.8vol% BTnf-Ag composite material has a dielectric constant of 82.6BTnf/PVDF, but the composite material’s dielectric constant is only 62.4, an increase of 32%. The dielectric loss of the 41.8vol% BTnf-Ag composite material is 0.053, and the dielectric loss constant of the BTnf/PVDF composite material is 0.049; the dielectric loss is reduced by 8% year-on-year. Ferroelectric ceramic composites prepared by adding silver ions have ideal dielectric properties and enhanced energy storage density.

Enhanced energy storage density with excellent temperature-stable dielectric properties of (1-x)[(Bi0.5Na0.5)0.94Ba0.06TiO3]-xAgNbO3 lead-free ceramics

Lead-free (1-x)[(Bi0.5Na0.5)0.94Ba0.06TiO3]-xAgNbO3 (abbreviated as BNTBT-100xAN) ceramics were fabricated using a conventional solid-phase reaction technique. The effect of the antiferroelectric AgNbO3 dopants for fatigue resistance, energy-storage density, temperature-stable permittivity, and conductivity mechanism was systematically investigated. The addition of AgNbO3 led to the decrease of remnant polarization and the increase of dielectric breakdown strength, a large effective energy-storage density of ~1.27 J/cm3 corresponding to the conversion efficiency of ~ 77.5% for BNTBT-5AN ceramic were attained under applied 105 kV/cm field. Meanwhile, it exhibited an outstanding fatigue-resistant performance at 70 kV/cm fixed field up to 105 cycles accompanied with excellent temperature-stable properties in the temperature range of 30 °C ~ 120 °C. Besides, BNTBT-5AN sample has also obtained outstanding temperature-stable permittivity, which was associated with the enhancement of the ergodic relaxor domain structure. A little variance of dielectric content (Δε'/ε'150 °C ≤ ± 15%) was acquired from 40 °C to 387 °C with a small tangent loss (tanδ ≤ 0.05) between 50 °C and 461 °C. Hence, it revealed that the high energy storage properties and excellent dielectric temperature stability for BNTBT-5AN ceramic were conducive to its better applications in electronic equipment.

Polyimide Nanodielectrics Doped with Ultralow Content of MgO Nanoparticles for High-Temperature Energy Storage.

Advanced polymer dielectrics with high energy density at elevated temperatures are highly desired to meet the requirements of modern electronic and electrical systems under harsh conditions. Herein, we report a novel polyimide/magnesium oxide (PI/MgO) nanodielectric that exhibits high energy storage density (Ue) and charge–discharge efficiency (η) along with excellent cycling stability at elevated temperatures. Benefiting from the large bandgap of MgO and the extended interchain spacing of PI, the composite films can simultaneously achieve high dielectric constant and high breakdown strength, leading to enhanced energy storage density. The nanocomposite film doped with 0.1 vol% MgO can achieve a maximum Ue of 2.6 J cm−3 and a η of 89% at 450 MV m−1 and 150 °C, which is three times that of the PI film under the same conditions. In addition, embedding ultralow content of inorganic fillers can avoid aggregation and facilitate its large-scale production. This work may provide a new paradigm for exploring polymer nanocomposites with excellent energy storage performance at high temperatures and under a high electric field.

Enhanced energy storage density in poly(vinylidene fluoride-hexafluoropropylene) nanocomposites by filling with core-shell structured BaTiO3@MgO nanoparticals

Filling with high dielectric constant inorganic nanoparticles is an effective approach to enhance the energy storage performance of an organic dielectric. However, the dielectric mismatch between ceramic and polymer causes early breakdown, which limits the storage density of ceramic/polymer nanocomposites in the application of dielectric capacitors. Herein, we employed MgO as a buffer barrier to mitigate the mismatched dielectric characteristics among BaTiO3 (BT) nanoparticles and poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) substrate considering its high insulation and medium dielectric constant. The alien oxide was coated on the spherical BT by a simple chemical precipitation process, forming a BaTiO3@MgO (BT@MgO) core-shell nanostructure, which has been carefully examined by TEM and EDS. The BT-MgO heterogeneous interfacial region provides channels for carriers and promotes charge movement, and therefore the dielectric constant and potential shift have been significantly enhanced. The BT@MgO/P(VDF-HFP) nanocomposite with 1 vol% filling ratio delivered a maximum energy density Ud, and the value reaches up to 5.6 J/cm3 that is 40.0 % and 55.6 % greater than that of the host matrix and BT-filled counterpart with the same filler amount. The BT@MgO core-shell nanostructure demonstrates an alternative way to effectively heighten the energy storage performance of ceramic/polymer composite dielectrics.