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1.
Lead-free ceramics with prominent energy storage properties are identified as the most potential materials accessed in the dielectric capacitors. Nevertheless, high recoverable energy storage density (Wrec), large energy storage efficiency (η) and preferable temperature stability can hardly be met simultaneously. The Bi(Zn2/3Ta1/3)O3 and NaNbO3 components are doped in KNN ceramics to substantiate the reliability of this tactic. A high recoverable energy density (Wrec) of ~ 4.55 J/cm3 and a large energy storage efficiency (η) of ~ 87.8% are acquired under the dielectric breakdown strength (DBS) of ~ 375 kV/cm, along with a splendid thermal stability (Wrec variation: ~ 2.3%, η variation: ~ 4.9%) within the temperature range of 20 ℃? 120 ℃. This article demonstrates that the KNN-based ceramics integrate high energy storage properties and outstanding temperature stability at the same time, which broadens the application fields of pulse power systems.  相似文献   

2.
Developed ceramic capacitors with excellent recoverable energy storage density (Wrec) and efficiency (η) are greatly desired for next-generation pulsed power devices but challenge as well. Herein, outstanding Wrec of 5.2 J/cm3 and η of 82% are achieved in the PbO-doped fine grain Bi0.25Na0.25Sr0.5TiO3 (BNST-P) based relaxor ferroelectric ceramics. The corresponding mechanism is that A-site Pb-doping increases maximum polarization and breakdown strength, and suppresses remnant polarization simultaneously. Meanwhile, the energy storage property possesses excellent temperature and frequency stability, and the variation of Wrec and η is less than 5% within the range of 25–100 °C and 2–100 Hz. Encouragingly, superior charge-discharge performance with fast discharge speed t0.9 of 24 ns and high power density PD of 296 MW/cm3 is obtained. These striking comprehensive results suggest BNST-P ceramics possess potential prospects for applications.  相似文献   

3.
《Ceramics International》2023,49(19):31152-31162
There is still a problem of low energy storage density in dielectric capacitors which is a core component of power systems. For the improvement of the energy storage density, the linear dielectric material CaTiO3 (CT) was introduced in Na0.5Bi0.5TiO3 (NBT) ceramics in this paper. By modifying the A site, a new relaxor ferroelectric ceramic was successfully synthesized and attained a recoverable density (Wrec) of 2.34 J/cm3 at x = 0.18. Moreover, the preparation process was optimized in this paper. Through the viscous polymer process (VPP) route, the energy density (WA) of 82NBT-18CTVPP ceramic further reaches 6.45 J/cm3 at 340 kV/cm, with efficiency (η) up to 75% and a Wrec of 4.82 J/cm3. At the same time, the change of Wrec is small at temperature (30–150 °C) and frequency (1 Hz–300 Hz), which demonstrates its excellent stability. The discharge power density reaches about 180 MW/cm3 and the discharge time is 0.117 μs, which indicates its excellent pulse discharge performance. The results show that 82NBT-18CT lead-free relaxation ferroelectric material is expected to become ideal for high-energy storage applications.  相似文献   

4.
《Ceramics International》2022,48(20):30066-30077
Currently, Bi0.5Na0.5TiO3-based lead-free ferroelectrics have attracted considerable attention as one of the promising candidates for dielectric materials due to their large spontaneous polarization, environmental friendliness and low cost. However, their poor energy density hinder the practical application of the materials. Herein, a novel ceramic of (1-x) (0.94Bi0.5Na0.5TiO3-0.06BaTiO3)-x(0.96NaNbO3-0.04CaSnO3) (BNBT-xNNCS) has been developed by the solid solution of antiferroelectric NaNbO3–CaSnO3 into ferroelectric Bi0.5Na0.5TiO3–BaTiO3 and the microstructure and electrical properties of the material have been systematically investigated. All the ceramics are lied within the coexistence zone of tetragonal (T) and rhombohedral (R) phases, ensuring to the large polarizations of the materials. Importantly, the introduction of NaNbO3–CaSnO3 shifts dielectric peaks at Ts towards room temperature and simultaneously broadens and flattens the dielectric peaks, destroying the ferroelectric long-range order of ferroelectric domains and inducing the generation of polar nanoregions (PNRs) to reduce the remanent polarization. As a result, the prominent energy storage properties with the charge energy storage density (Wtot) of 1.86 J/cm3, recoverable energy density (Wrec) of 1.64 J/cm3 and energy storage efficiency (η) of 88.23% are obtained in the BNBT-xNNCS ceramics with x = 0.20 (BNBT-20NNCS) under a comparatively low electric field strength of 149 kV/cm, accompanying with superior frequency (ΔWrec ≤ 3%, Δη ≤ 3%, 30–90 Hz) and thermal stability (ΔWrec ≤ 10%, Δη ≤ 10%, 25–175 °C).  相似文献   

5.
《Ceramics International》2021,47(18):25794-25799
To develop and fabricate environmentally friendly dielectric capacitors used in high-temperature environment, in this work, we prepare La3+ doped 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 lead-free relaxor ferroelectric ceramics with high and wide phase transition temperature. With the introduction of La3+, due to the enhancement of the A- and B- site cation ion disorder, the dielectric relaxation characteristics of the ceramics are more obvious. Therefore, the polarization-electric field loops become slimmer and the remnant polarization (Pr) reduces. In addition, because La3+ as a donor dopant has lower mobility than A-site cation ions in the ceramic matrix, the grain sizes decrease with increasing La3+ content, which significantly leads to an increase in the breakdown strength (Eb). As a result, both a large recoverable energy density (Wrec) of 1.92 J/cm3 and a high energy efficiency (η) of 85.7% are obtained in the ceramic with 12 mol% La3+ content. More importantly, even at 200 °C and a low driving electric field of 155 kV/cm, the Wrec and η of this kind of ceramic are still as high as 1.2 J/cm3 and 89.4%, indicating good temperature stability. This work provides an effective and simple way to prepare environmentally friendly dielectric capacitors that are applicable in high-temperature environment.  相似文献   

6.
Dielectric ceramics with a high recoverable energy density (Wrec) and high efficiency are desirable for the development of pulsed power capacitors under low electric fields. In this study, through the introduction of SrSc0.5Nb0.5O3 into (Bi0.5Na0.5Ti0.95Al0.025Nb0.025O3) [(1-x)BNTA-xSSN], a considerable recoverable energy storage density (Wrec) of approximately 2.7 J/cm3 and energy storage efficiency (η) of approximately 76 % at 210 kV/cm are achieved at x = .1; additionally, η is further improved to 85 % at x = .2. Moreover, η and Wrec of .9BNTA-.1SSN exhibit outstanding stability (thermal and frequency stability) at 150 kV/cm, which is superior to that of other lead-free ceramics. The excellent energy storage performance is attributed to the increased relaxation degree and the formation of ferroelectric nanodomains, whereas the enhanced Eb is ascribed to the increased electrical resistivity and decreased grain size upon modification. These results indicate the potential of (1-x)BNTA-xSSN as an ideal candidate for energy-storage applications.  相似文献   

7.
《Ceramics International》2021,47(18):25800-25809
High energy storage and charge-discharge performances under low electric field are desirable for lead-free dielectric materials because of environmental hazards, the risk of high voltage and the high cost of insulation technology. Herein, lead-free ceramics based on 0.6BNT-0.4Sr0.775Bi0.15TiO3 (BNT-SBT) were designed, which simultaneously achieves a large energy storage density (Wrec~ 2.41 J/cm3) and a high efficiency (η~87.5%) under a low electric field of 190 kV/cm due to enhanced dielectric properties and the relaxation response. Moreover, the energy storage properties of the BNT-SBT ceramic exhibit moderate temperature stability, excellent frequency dependence, and cycling reliability. Furthermore, the charge-discharge performance simultaneously features a high power density (PD~51.4 MW/cm3), an ultrafast discharge speed (t0.9–77 ns), and remarkable stability against temperature and cycling. This study exploits a high-efficiency BNT-related ceramics with concurrently high energy storage and charge-discharge performances under low electric fields, which provides great potential in practical dielectric capacitor applications.  相似文献   

8.
《Ceramics International》2022,48(15):21407-21415
This work presents a simple process to fabricate Na0.5Bi0.5(Ti0.97Fe0.03)O3/Ba(1–x)SrxTiO3–based heterostructure thin films with a compositional graded sequence, and their energy storage properties are investigated systematically. A simulation technique is used to predict the experimental results. Interestingly, improved energy storage properties are obtained in the “up–graded” film, which is associated with the stress/strain. Furthermore, the “up–graded” film after aging with treating exhibits a higher breakdown strength (EBD = 3176.4 kV/cm), recoverable energy storage density (Wrec = 67.18 J/cm3) and efficiency (η = 75.65%). This can be attributed to the ordered defect dipoles induced by aging with treating driving domain switching, which is favorable for high (PmPr) and large Wrec. These results provide an approach and guidance to design thin film-based devices with optimal energy storage performance.  相似文献   

9.
The application of advanced pulse power capacitors strongly depends on the fabrication of high-performance energy storage ceramics. However, the low recoverable energy storage density (Wrec) and energy efficiency (η) become the key links limiting the development of energy storage capacitors. In this work, a high Wrec of ~5.57 J cm?3 and a large η of ~85.6% are simultaneously realized in BaTiO3-based relaxor ceramics via multi-dimensional collaborative design, which are mainly attributed to the ferroelectric-relaxor transition, enhanced polarization, improved breakdown electric field, and delayed polarization saturation. Furthermore, the excellent temperature stability (ΔWrec < ± 5%, 25–140 °C), frequency stability (ΔWrec < ± 5%, 1–200 Hz), and outstanding charge/discharge performance (current density ~1583.3 A cm?2, power density ~190.0 MW cm?3) with good thermal stability are also achieved. It is encouraging that this work demonstrates that multi-dimensional collaborative design is a good strategy to develop new high-performance lead-free materials used in advanced dielectric capacitors.  相似文献   

10.
《Ceramics International》2020,46(9):13159-13169
Lead-free perovskite dielectric materials for capacitors have received wide concern in recent years, but their energy storage density and efficiency still cannot meet the growing application demand for practical applications. In this work, we prepared a lead-free relaxor ferroelectric ceramic of (1-x)Bi0.47Na0.47Ba0.06TiO3-xSr(Zr0.8Nb0.16)O3, which was synthesized via a normal solid-state route. The microstructure, dielectric properties and energy storage behavior of the ceramics were explored. The ceramics can be well sintered and situated in the region where rhombohedral and tetragonal phases coexist. The addition of Sr(Zr0.8Nb0.16)O3 (SZN) significantly extends the dielectric-temperature plateau between Ts and Tm and reduces the remnant polarization Pr, but the large saturation polarization Ps is still maintained. Besides, the doping of SZN enhances the relaxation of the material and increases the dielectric breakdown strength (DBS) from 50 kV/cm (x = 0) to 100 kV/cm (x = 0.04 and 0.06). Therefore, the ceramic with x = 0.06 exhibits a high discharging efficiency (η) of 71.1% and energy density (W) of 1.56 J/cm3 at 100 kV/cm and shows the superior thermal stability with the changes in recoverable energy density (Wrec) and η of less than 10% and 30% at the temperature range of 25–180 °C and the excellent frequency stability with the variations of Wrec and η of less than 1.8% and 1% at the frequency range of 10 Hz–100 Hz.  相似文献   

11.
《Ceramics International》2022,48(22):33553-33562
In this investigation, La2O3 was doped into 0.85(0.65BF-0.35BT)-0.15Sr0.7Bi0.2TiO3 (BF-BT-SBT) to form a solid solution with relaxation ferroelectric properties. The dielectric breakdown strength (BDS) of 1% mole of La doping was 220 kV/cm, the maximum recoverable energy storage (Wrec) was 2.35 J/cm3, and the energy storage efficiency (η) was 71%. The relationship between ceramic properties and microstructure was investigated in detail. Doping with La has the following main features: (1) The dissolution of La3+ ions in the A position of the original perovskite structure reduced the concentration of oxygen vacancies in the lattice and played a role of compensating the defects. (2) The dielectric loss of ceramics was reduced, the impedance was greatly increased, and the specimen exhibited a high-temperature stability: a maximum Wrec of 4.04 ± 1.7% J/cm3 in 30–130 °C. (3) The core–shell–like with single phase structure in La-doped ceramics had been successfully observed, which may become a strategy for preparing high-performance ceramics. Higher BDS and denser structures were obtained in 0.01 La ceramics by further optimizing the preparation of the above compositions by the viscous polymer process (VPP). The BDS of 0.01La ceramics prepared by VPP reached 480 kV/cm, the effective energy storage density reached 6.15 J/cm3, and the η was about 81%. This made La-doped 15SBT (chemical composition of BF-BT-SBT + La2O3) ceramics become a potential candidate material for energy storage devices.  相似文献   

12.
《Ceramics International》2022,48(21):31931-31940
(1-x)(0.75(Na0.5Bi0.5)TiO3-0.25SrTiO3)-xNdGaO3 ceramics (NBST-xNG, x = 0–0.06) were fabricated through a solid-state reaction method. High-valent Nd3+ ions enter the perovskite A-site to occupy Bi vacancies resulting from the volatilization of Bi, inhibiting the formation of oxygen vacancies and contributing to an enhanced breakdown electric field (Eb). Low-valent Ga3+ ions enter the B-site to substitute for Ti4+ ions, resulting in the formation of random electric fields (REFs) at the B-site due to co-occupying hetero-valence ions of Ga3+/Ti4+, which significantly reduces ferroelectric hysteresis. Therefore, a synergic effect of A- and B-sites co-doping was realized in NBST-xNG ceramics. Benefitting from this synergic effect, an enhanced recoverable energy storage density (Wrec) of 2.88 J/cm3 and an efficiency (η) of 83% are simultaneously obtained in NBST-0.04NG ceramics under a moderate electric field (E) of 200 kV/cm. Compared with most NBT-based ceramics, the values of (η vs Wrec/E2) for NBST-0.04NG ceramics show an obvious advantage, indicating excellent potential for application as an energy storage material. Moreover, Wrec and η of NBST-0.04NG ceramics exhibit excellent temperature stability from 30 °C to 200 °C due to the enhanced correlation strength of polar nanoregions (PNRs) and local structural stability. This work provides a potential strategy to improve the energy storage performance of NBT-based ceramics via the synergic effect of A- and B-site co-doping.  相似文献   

13.
《Ceramics International》2022,48(8):10789-10802
In this study, NaNbO3 (NN) was introduced into Ba(Zr0.15Ti0.85)O3 (BZT) to form a solid solution with relaxor ferroelectric characteristics. The dielectric breakdown strength (BDS) of the specimen with 6 mol.% NN reached 680 kV/cm, the corresponding recoverable energy storage density (Wrec) was 5.15 J/cm3, and the energy storage efficiency (η) was 77%. The dissolution of Na + ions at the A position and Nb5+ ions at the B position of the perovskite structure reduced the concentration of oxygen vacancies in the lattice and compensated for defects. The doped ceramics exhibited lower dielectric loss and better thermal stability: the Wrec value was 2 ± 1% J/cm3 at 30–120 °C. In particular, in the 0.02NN ceramics, a ΔT of 1.81 K was achieved at 130 kV/cm, and the operating temperature zone expanded with the increase in doping concentration. The introduction of NN resulted in BZT ceramics that possess excellent energy storage performance and electrocaloric effect properties.  相似文献   

14.
《Ceramics International》2022,48(6):7723-7729
Sodium niobate energy storage ceramics with high energy density and efficiency can be used as potential candidate materials for pulse power devices. Doping modification of dielectric ceramic matrixes is an effective means to obtain high performance. The (1-x)NaNbO3-xBi(Mg1/2Sb2/3)O3 ceramics were designed in this work. And 0.85NaNbO3-0.15Bi(Mg1/2Sb2/3)O3 showed a large Wrec of 4.65 J/cm3 at an Eb of 580 kV/cm. Excellent frequency stability of Wrec (1.67–1.7 J/cm3) and η (86%–89.1%) over frequency range of 1–100Hz was observed. Further, good temperature stability of Wrec (1.5–1.71 J/cm3) and η (68%–87%) over abroad temperature range of 20–180 °C was attained successfully. In addition, excellent power density (PD = 113 MW/cm3), large current density (CD = 1255 A/cm2) and discharge speed (0.51μs) were obtained, which demonstrates the great potential practical value of this ceramic in the energy storage applications.  相似文献   

15.
《Ceramics International》2022,48(5):6062-6068
As microelectronic devices move toward integration and miniaturization, the thin film capacitors with high energy density and charge/discharge efficiency have attracted immense interests in modern electrical energy storage systems. Despite morphotropic phase boundary (Na0.8K0.2)0.5Bi0.5TiO3-based lead-free materials with outstanding ferroelectric and piezoelectric properties, while large ferroelectric hysteresis with high remanent polarization (Pr) hinder to improve energy storage capability. Here, novel lead-free relaxor-ferroelectric (RFE) thin film capacitors with high energy density are successfully prepared in (1-x) (Na0.8K0.2)0.5Bi0.5TiO3-xBa0.3Sr0.7TiO3 [(1-x)NKBT-xBST] systems. Introducing BST into the NKBT systems is expected to reduce remanent polarization (Pr) on account of coupling reestablishment of the polar nano-regions (PNRs) and improving the relaxation behavior. As a result, 0.6NKBT-0.4BST thin film exhibits high energy density (Wrec ~ 54.79 J/cm3) together with satisfactory efficiency (η ~ 76.42%) at 3846 kV/cm. The stable energy storage performances are achieved within the scope of operating temperatures (20–200 °C) and fatigue cycles (1-107 cycles). This work furnishes a new technological way for the design of high energy-density thin film capacitors.  相似文献   

16.
The 0.63(1-x)Bi1.02FeO3-0.37BaTiO3-xBi(Zn2/3(Nb0.85Ta0.15)1/3)O3 (abbreviated BF-BT-xBZNT) high temperature dielectric ceramics were prepared via a two-step sintering (TTS) method. The appropriate medium permittivity achieved in the BF-BT-0.13BZNT ceramic is conducive to mitigating the polarization saturation and improving the breakdown field strength. The domain evolution behavior from piezoresponse force microscopy (PFM) reveals that the introduction of BZNT promotes the formation and switching of more nanodomains of BF-BT ceramics, facilitating the enhancement of energy storage efficiency. The excellent energy storage performance of total energy storage density (Wtot) of 6.06 J/cm3, recoverable energy storage density (Wrec) of 4.85 J/cm3 and a high energy storage efficiency (η) of 80% are simultaneously obtained under 410 kV/cm in the BF-BT-0.13BZNT ceramic. Meanwhile, the ceramic exhibits excellent thermal endurance (10–130 ℃), frequency (1–100 Hz) and fatigue (105 cycles) stability. The current work provides a promising strategy for designing high-performance dielectric energy storage materials which operate in harsh environments.  相似文献   

17.
Development of lead-free dielectric capacitors with high recoverable energy storage density (Wrec), large energy storage efficiency (η), and wide usage temperature range are in high demanded for pulse power systems. Herein, we realized the enhancement of energy storage properties [high Wrec = 3.76 J/cm3, large η = 78.80 %, and broad operating temperature range (20?180 °C)] in lead-free Na0.5Bi0.5TiO3 (BNT)-based relaxor ferroelectrics via component regulation. Excellent energy storage properties mainly originate from suppressing early polarization saturation and improving dielectric breakdown strength (Eb). Domain evolution on the nanoscale offers robust support to suppression of early polarization saturation. The enhancement of Eb can be derived from the contribution of the Mg-rich phase, which is also corroborative via first-principles calculation on basis of density functional theory (DFT). We believe that these findings in this work may provide a practicable guideline to build new lead-free ceramics for electrical energy storage applications.  相似文献   

18.
《Ceramics International》2023,49(12):19701-19707
It is difficult to obtain high polarization strength and high breakdown strength synchronously, resulting in the drawback of lower energy storage density, which inhibits commercial application of energy storage materials. We have successfully prepared (1-x)(0.93Bi0.5Na0.5TiO3-0.07CaSnO3)-xSrTiO3 (BNT–CS–xST) ceramics by solid-state method. The presence of polymorphic nanodomains and the large electric displacement generated by the high charge Sr2+-Sr2+ ion pairs help to delay saturation polarization (Pm ∼ 48.64 μC/cm2 at 315 kV/cm). In addition, the breakdown field strength (Eb) is increased by grain refinement and increasing the band gap. It is noteworthy that a high recoverable energy storage density (Wrec = 4.2 J/cm3) and a great efficiency (η = 88%) were achieved simultaneously in BNT–CS–0.5ST ceramic. Moreover, excellent charge-discharge performance was also achieved, with a discharge energy density Wd of 2.2 J/cm3, a current density CD of 1724 A/cm2 and a power density PD of 250 MW/cm3. The study demonstrates that the great potential of BNT–CS–xST ceramics in power storage devices and provides an effective strategy for designing ceramics dielectric capacitors with excellent performance.  相似文献   

19.
BiFeO3-BaTiO3-based relaxor ferroelectric ceramic has attracted increasing attention for energy storage applications. However, simultaneously achieving high recoverable energy storage density (Wrec) and efficiency (η) under low electric field has been a longstanding drawback for their practical applications. Herein, a novel relaxor ferroelectric material was designed by introducing (Sr0.7Bi0.2)TiO3 (SBT) into the composition 0.67BiFeO3-0.33BaTiO3 (BF-BT-xSBT). A large Wrec of ∼2.40 J/cm3 and a high η of ∼90.4 % were simultaneously realized under a low electric field of 180 kV/cm, which is superior to that of most previously reported lead-free ceramics. Moreover, moderate temperature endurance and excellent frequency stability were also obtained. More importantly, this ceramic has a large discharge current density (∼289.18 A/cm2), a discharge power density (∼14.46 MW/cm3) and short discharge time (<0.25 μs). These results not only demonstrate superior potential in BF-BT-SBT ceramics, but also offer a new design to tune the energy storage performance of lead-free relaxor ferroelectric ceramics.  相似文献   

20.
《Ceramics International》2021,47(20):28493-28499
Lead-free antiferroelectric (AFE) NaNbO3 (NN) is one of promising materials for dielectric capacitors, but the recoverable energy-storage density and efficiency get restrained owing to huge remanent polarization and limited dielectric breakdown field strength. In this work, a variety of NN based lead-free bulk (1-x)NaNbO3-xLa(Mn0.5Ni0.5)O3 (abbreviated as (1-x)NN-xLMN, x = 0, 0.05, 0.10, 0.15, 0.20) ceramics were designed using a solid-state synthesis method. Remarkably, an ultra-fast charge-discharge speed 47 ns and an acceptable recoverable energy-storage density Wrec ~1.77 J/cm3 with a high efficiency η = 77% were obtained under the Eb of 200 kV/cm at x = 0.05. The superior energy storage performance is attributed to the regulation of domain size and voltage resistance by special ions substitution of A and B sites. This work not only proposes an efficient strategy to realize high recoverable energy-storage density and efficiency, but also provide an candidate material for application of advanced pulsed power capacitors.  相似文献   

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