Large field-induced strain with enhanced temperature-stable dielectric properties of AgNbO3-modified (Bi0.5Na0.5)0.94Ba0.06TiO3 lead-free ceramics

(1-x)(Bi_0.5Na_0.5)_0.94Ba_0.06TiO₃-xAgNbO₃ lead-free piezoelectric ceramics (abbreviated as BNBT-100xAN) were prepared using the conventional solid-state sintering method. The effects of the introduction of AgNbO₃ (AN) dopants for the dielectric and piezoelectric performances of BNBT-100xAN ceramics were systematically studied. The XRD patterns and Raman spectra demonstrated that AN as a modifier was successfully diffused into the BNBT-100xAN lattice and revealed a pseudo-cubic symmetry structure. All samples exhibited a dense surface morphology accompanied by the uniform distribution of elements. A large bipolar strain of ~0.501% and unipolar strain of ~0.481% corresponding to the normalized strain d₃₃* of ~740 p.m./V were achieved for BNBT-1AN ceramic at 65 kV/cm field. The BNBT-4AN ceramic exhibited an excellent temperature-stable permittivity with the range from 59 to 380 °C and its dielectric loss was less than 0.02 between 97 °C and 329 °C. These results revealed that BNBT-100xAN ceramics were more hopeful candidates for actuators, strain sensors, and high-temperature capacitors.     

High energy storage performance of [(Bi0.5Na0.5)0.94Ba0.06]0.97La0.03Ti1-x(Al0.5Nb0.5)xO3 ceramics with enhanced dielectric breakdown strength

Novel lead-free [(Bi_0.5Na_0.5)_0.94Ba_0.06]_0.97La_0.03Ti_1-x(Al_0.5Nb_0.5)_xO₃ ceramics (BNBLT-xAN) were prepared by the conventional solid state sintering method. The dielectric, ferroelectric, ac impedance and energy-storage performance were systematically investigated. Temperature dependent permittivity curves showed that relaxation properties of sintered ceramics gradually diminished with the increase of AN. The introduction of AN gave rise to a slimmer polarization hysteresis loop (P-E) and an enhanced dielectric breakdown strength (DBS). Therefore, the optimum energy-storage performance were realized at x?=?0.05 with the energy-storage density (W_rec) of 1.72?J/cm³ and energy-storage efficiency (η) of 85.6% at 105?kV/cm, accompanied with the excellent temperature stability and fatigue performance. The results demonstrated that BNBLT-xAN system was a promising lead-free candidate for energy-storage applications.     

High energy-storage performance of lead-free Ba0.4Sr0.6TiO3–Sr0.7Bi0.2TiO3 relaxor-ferroelectric ceramics with ultrafine grain size

Relaxor-ferroelectric (RFE) ceramics possess slender ferroelectric hysteresis loop and low remnant polarization (P_r). They have great potential to provide excellent energy-storage performance as dielectric energy-storage materials. Herein, a lead-free 0.8Ba_0.4Sr_0.6TiO₃–0.2Sr_0.7Bi_0.2TiO₃ (0.8BST–0.2SBT) RFE ceramic with high energy-storage performance has been realized successfully. The addition of Bi³⁺ and increase in Sr²⁺content at the A site of the BST can effectively inhibit the growth of grains for high breakdown strength (E_b). As a result, an ultrafine average grain size of 0.7 μm was obtained in 0.8BST–0.2SBT RFE ceramic, affording a high E_b of 300 kV/cm. Further investigation revealed that the mutual conversion of short-range polar nanoregions and long-range-ordered ferroelectric domains upon application and withdrawal of a 300 kV/cm applied electric field resulted in a high maximum polarization (P_max) of 31 μC/cm² and a low P_r of 2.5 μC/cm². Hence, the 0.8BST–0.2SBT RFE ceramic simultaneously exhibited a high recoverable energy-storage density of 3.3 J/cm³ and a high energy-storage efficiency of 85% at 300 kV/cm. Additionally, a good energy-storage performance was reported over a temperature range of 50°C-120 °C and frequency from 10 to 1000 Hz, making the 0.8BST-0.2SBT RFE ceramic a potential lead-free dielectric energy-storage material.     

Excellent energy storage properties over a wide temperature range under low driving electric fields in NBT-BSN lead-free relaxor ferroelectric ceramics

To develop environment-friendly dielectric capacitors with low working electric field and wide useable temperature, in this work, we fabricate (1-x)Na_0.46Bi_0.54TiO₃- xBaSnO₃((1-x)NBT-xBSN) lead-free relaxor ferroelectric ceramics by adding BaSnO₃ into Na_0.46Bi_0.54TiO₃ matrix. BSN exhibits slim polarization-electric field (P-E) loops, small remnant polarization (P_r) and good temperature stability because of its room-temperature paraelectric characteristics, and has different cation ionic radii with Na_0.46Bi_0.54TiO₃. Therefore, when BSN is introduced into NBT, the relaxor behavior of the (1-x)NBT-xBSN ceramics is more pronounced and the P-E loops are much slimmer. Besides, because the substitution of Ba²⁺ ions with higher valence for Na⁺ ions neutralizes the hole carriers, which are caused by the volatilization of Na₂O, the resistivity and breakdown strength are improved with increasing BSN content. As a consequence, at x = 0.30, the ceramic exhibits simultaneously a large recoverable energy density (W_rec) of 1.51 J/cm³ and high energy efficiency (η) of 81.2% at a low driving electric field of 145.3 kV/cm because of the collaborative enhancement effect of the high breakdown strength and low remnant polarization. More interestingly, variations of the W_rec and the η for this kind of ceramic are respectively as small as 10% and 0.8% over a wide temperature range of 20–140 °C, demonstrating superior temperature stability. In this report, we provide a new and efficient way for designing and fabricating environment-friendly dielectric capacitors with good reliability and superior high-temperature energy storage capacity.     

Highly-reliable dielectric capacitors with excellent comprehensive energy-storage properties using Bi0.5Na0.5TiO3-based relaxor ferroelectric ceramics

The development of capacitors with high reliability and good comprehensive performances is of great significance for practical applications. In this work, lead-free relaxor ferroelectric (FE) ceramics of (1-x)(0.5(Bi_0.5Na_0.5)TiO₃-0.5SrTiO₃)-xBi(Mg_2/3Nb_1/3)O₃ ((1-x)(BNT-ST)-xBMN) were prepared by a conventional solid-state reaction method. The introduction of BMN was found to enhance local structure disorder, leading to the significantly reduced size of FE nanodomains, which is responsible for the slim polarization-electric field hysteresis loops. A giant energy-storage density of 6.62 J/cm³ and a high efficiency of 82 % can be achieved simultaneously under a moderate electric field of 34 kV/mm at x = 0.08. It also exhibits high discharge density ～ 2.74 J/cm³, large power density ～ 248 MW/cm³ and ultrafast discharge rate ～ 28 ns at 20 kV/mm in addition to excellent temperature (10–130 °C) and frequency (1–100 Hz) stabilities. These results demonstrate that the (1-x)(BNT-ST)-xBMN ceramic system is a promising lead-free candidate for advanced pulsed power capacitor applications.     

Enhanced energy-storage properties of (1-x)(0.7Bi0.5Na0.5TiO3-0.3Bi0.2Sr0.7TiO3)-xNaNbO3 lead-free ceramics

A series of (1-x)(0.7Bi_0.5Na_0.5TiO₃-0.3Bi_0.2Sr_0.7TiO₃)-xNaNbO₃ (BNT-BST-100xNN) lead-free ceramics were fabricated using conventional solid-state reaction technique. The phase behavior, microstructure, dielectric, ac impedance and energy-storage properties of the sintered ceramics were systematically investigated. XRD patterns and surface SEM micrographs revealed the introduction of NaNbO₃ didn't change the perovskite structure of BNT-BST at low doping level. The NaNbO₃ doping gave rise to slimmer P-E loops and thus gained enhanced energy storage properties. Therefore, a maximum energy storage density of 1.03 J/cm³ was achieved at 85 kV/cm at x = 0.01 via increasing the dielectric breakdown strength (DBS). Temperature-dependent dielectric permittivity illustrated the enhanced relaxor characteristics, implying the long-rang ferroelectric order was further damaged due to the introduction of NaNbO₃. The results above indicate the sintered ternary ceramics can be a promising lead-free candidate for energy storage capacitors.     

Large electrostrain and high energy-storage of (1-x)[0.94(Bi0.5Na0.5) TiO3-0.06BaTiO3]-xBa(Sn0.70Nb0.24)O3 lead-free ceramics

(1-x)[0.94(Bi_0.5Na_0.5)TiO₃-0.06BaTiO₃]-xBa(Sn_0.70Nb_0.24)O₃ (abbreviated as BNTBT-100xBSN) lead-free ceramics were fabricated with a relative density greater than 96 %, and the structure as well as performance were tested. BNTBT-100xBSN ceramics are pseudo-cubic perovskite structure, with dense surface morphology. Doping BSN can effectively reduce the dielectric loss of ceramics and increase the relaxation properties to a certain extent. The randomly distributed ferroelectric phase was replaced by polar nano regions, thereby improving the electro-strain and energy storage performance of the system. The largest electro-strain and the corresponding normalized strain (d₃₃*) reach ~ 0.43 % and 633 pm/V respectively in the BNTBT-1BSN ceramic. The largest effective energy storage density reaching ~ 1.28 J/cm³ was tested in BNTBT-2BSN. BNTBT-100xBSN ceramics provide a feasible idea for the systematic research of lead-free ferroelectrics and improvements in electro-strain and energy storage applications.     

Effects of Mn doping on dielectric properties and energy-storage performance of Na0.5Bi0.5TiO3 thick films

Lead-free Na_0.5Bi_0.5Ti_1−xMn_xO₃ (NBTMn_x, x=0, 0.01, 0.03 and 0.05) ferroelectric thick films have been fabricated on LaNiO₃/Si(100) substrate by using a polyvinylpyrrolidone-modified sol-gel method and the effects of Mn content on their microstructure, dielectric properties and energy-storage performance were investigated. Compared with the pure Na_0.5Bi_0.5TiO₃ (NBT) thick films, NBTMn_x thick films exhibited a large enhancement in dielectric properties and energy-storage performance. Particularly, a giant recoverable energy-storage density (W) of 30.2 J/cm³ and the corresponding efficiency (η) of 47.7% were obtained in NBTMn_0.01 thick film at 2310 kV/cm. Moreover, the NBTMn_0.01 thick film displayed good energy-storage stability over a large temperature range at different frequency.     

Dielectric and Raman Spectroscopic Studies of Na0.5Bi0.5TiO3–BaSnO3 Ferroelectric System

A series of lead‐free perovskite solid solutions of (1 ? x) Na_0.5Bi_0.5TiO₃(NBT)—x BaSnO₃(BSN), for 0.0 ≤ x ≤ 0.15 have been synthesized using a high‐temperature solid‐state reaction route. The phase transition behaviors are studied using dielectric and Raman spectroscopic techniques. The ferroelectric to relaxor phase transition temperature (T_FR) and the temperature corresponding to maximum dielectric permittivity (T_m) are estimated from the temperature‐dependent dielectric data. Dielectric studies show diffuse phase transition around ~335°C in pure NBT and this transition temperature decreases with increase in x. The disappearance of x‐dependence of A₁ mode frequency at ~134 cm^?1 for x ≥ 0.1 is consistent with rhombohedral‐orthorhombic transition. In situ temperature dependence Raman spectroscopic studies show disappearance and discontinuous changes in the phonon mode frequencies across rhombohedral (x < 0.1)/orthorhombic (x ≥ 0.1) to tetragonal transition.     

Enhanced energy storage properties in La(Mg1/2Ti1/2)O3-modified BiFeO3-BaTiO3 lead-free relaxor ferroelectric ceramics within a wide temperature range

A new ternary lead-free (0.67-x)BiFeO₃-0.33BaTiO₃-xLa(Mg_1/2Ti_1/2)O₃ ferroelectric ceramic exhibited an obvious evolution of dielectric relaxation behavior. A significantly enhanced energy-storage property was observed at room temperature, showing a good energy-storage density of 1.66 J/cm³ at 13 kV/mm and a relatively high energy-storage efficiency of 82% at x = 0.06. This was basically ascribed to the formation of a slim polarization-electric field hysteresis loop, in which a high saturated polarization P_max and a rather small remnant polarization P_r were simultaneously obtained. Particularly, its energy storage properties were found to depend weakly on frequency (0.2 Hz–100 Hz), and also to exhibit a good stability against temperature (25 °C–180 °C). The achievement of these characteristics was attributed to both a rapid response of the electric field induced reversible ergodic relaxor to long-range ferroelectric phase transition and a typical diffuse phase transformation process in the dielectric maxima.     

Influence of BaSnO3 additive on the energy storage properties of Na0.5Bi0.5TiO3-based relaxor ferroelectrics

(1-x)NBT-xBSN (0.1?≤?x?≤?0.35) ceramics were prepared by solid state methods and their energy storage properties and high-temperature capacitor applications were systematically investigated. All samples showed a perovskite structure and the structure transformed to lower symmetry orthorhombic phase (x?≥?0.1) from rhombohedral phase (x?<?0.1) to with the addition of BSN. The more addition content of BSN significantly decreases phase transition temperature T_m of NBT ceramics. The x?=?0.25 sample exhibits a stable relative permittivity of 1605?±?15% in a broad temperature range of 38?°C to 319?°C. With increasing BSN concentration, the slope of the P-E loops and the energy loss gradually decreases. When x?=?0.25, a high breakdown strength of 190?kV/cm and the maximum discharge energy density of 1.91?J/cm³ were obtained, of which the energy efficiency was as high as 86.4%. Thus, it was believed that our work could provide a significant guidance for designing the new system for energy storage.     

Microstructure,dielectric, piezoelectric,and ferroelectric properties of fine-grained 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 ceramics

For preparing fine-grained 0.94Na_0.5Bi_0.5TiO₃-0.06BaTiO₃ lead-free ferroelectric ceramics, the precursor powders were synthesized via sol-gel method and calcined at various temperatures. The precursor powders calcined at 520 °C, 550 °C, and 600 °C exhibit mean grain sizes of 30 ± 4 nm, 54 ± 3 nm, and 78 ± 5 nm, respectively. By optimizing the synthesis parameters, the fine-grained ceramics with high relative densities (>97%) and mean grain size around 100 nm were prepared. The ferroelectric, dielectric, and piezoelectric behavior were investigated. The ceramics prepared using the different precursor powders show different piezoelectric, ferroelectric, and dielectric behavior. The ceramic calcined at 550 °C and sintered at 900 °C exhibits the breakdown strength higher than 85 kV/cm, which exhibits the maximum polarization of 38.4 ± 0.3 μC/cm², remanent polarization of 20.6 ± 0.4 μC/cm².     

High temperature stable dielectric properties and enhanced energy-storage performance of (1− x)(0.85Na0.5Bi0.5TiO3 − 0.15Ba0.8Ca0.2Ti0.8Zr0.2O3)− xK0.5Na0.5NbO3 lead-free ceramics

Novel high temperature ceramic capacitors (1??x)(Na_0.5Bi_0.5TiO₃ ??0.15Ba_0.8Ca_0.2Ti_0.8Zr_0.2O₃)??xK_0.5Na_0.5NbO₃ were synthesized in the solid-state reaction route. The influence of K_0.5Na_0.5NbO₃ modification on dielectric behavior, energy-storage properties, ac impedance and temperature stable dielectric performance were systematically investigated. The reduced grain size and enhanced relaxor properties are obtained with the addition of KNN. The content of x?=?0.1 exhibits a stable permittivity (~ 1630) and dielectric loss (<?0.05) over a relatively broad temperature range (66–230?°C). A variation in permittivity within ±?15% can be observed over a pretty wide temperature range of 66–450?°C. Beyond that, this ceramic shows enhanced energy-storage properties with the density (W_rec) of 0.52?J/cm³ and efficiency (η) of 80.3% at 110?kV/cm. The possible contributions of the grain and the grain boundary to the ceramic capacitance are discussed by the ac impedance spectroscopy.     

Structure,dielectric, and ferroelectric properties of (1-x)Bi0.5Na0.5TiO3 – X K0.5Na0.5NbO3 (0 ≤ x ≤ 0.1) solid solution

The correlation of the phase structure, dielectric, and ferroelectric properties of lead-free (1-x)(Na_0.5Bi_0.5)TiO₃–xK_0.5Na_0.5NbO₃ (NBTKNx) (0 = x ≤ 0.1) polycrystalline ceramics, fabricated via a solid state reaction technique, were investigated. The Rietveld refinement allowed identifying the crystallographic transformation from a rhombohedral to a coexisting rhombohedral-tetragonal or tetragonal long range-ordered ferroelectric (FE) phase. The dielectric investigations showed an increase of the dielectric diffuseness (1.53 = γ ≤ 1.73) and a clear shift of the depolarization temperature (T_d) to a lower temperature while increasing substitution. More importantly, the lattice disorder also generated a plateau-like dielectric anomaly, leading to a thermally stable ϵ_r ∼2859 ± 20% (120–500 °C) and ∼3112 ± 10% (120–420 °C) for x = 0.075 and 0.1 samples, respectively. At room temperature (RT), Raman spectroscopy investigations revealed a downshift of the frequencies as a function of the composition with an inhomogeneous broadening of the Raman lines. On heating, Raman spectra showed changes in the region where the dielectric transitions are observed. Moreover, the composition dependence of the current peaks in the I-E loops confirmed the occurrence of a phase transition from a non-ergodic polar phase to an ergodic weakly polar after the applying of an electric field of 60 kV/cm⁻¹.     

Dielectric behavior and impedance spectroscopy in lead-free BNT–BT–NBN perovskite ceramics for energy storage

The dielectric behavior, impedance spectroscopy and energy-storage properties of 0.85[(1−x)Bi_0.5Na_0.5TiO₃–xBaTiO₃]–0.15Na_0.73Bi_0.09NbO₃ [(BNT–xBT)–NBN] ternary ceramics were investigated. Temperature dependent permittivity curves displayed two depressed anomalies, resulting in significantly improved dielectric temperature stability. (BNT–9BT)–NBN showed a permittivity of 1680 at 150 °C with Δε/ε_150 °C varying no more than ±10% up to 340 °C. From the complex impedance analysis, grain and grain boundary shared the same time constant. The high temperature resistivity followed the Arrhenius law with E_a=1.7–2.0 eV, suggesting intrinsic band-type electronic conduction. The maximum energy-storage density of all the samples reached 1.1–1.4 J/cm³, accompanied with good temperature stability in the range of 25–140 °C. These results indicate that (BNT–xBT)–NBN system should be a promising lead-free material for energy-storage capacitor applications.     

Dielectric,impedance and piezoelectric properties of (K0.5Nd0.5)TiO3-doped 0.67BiFeO3-0.33BaTiO3 ceramics

A novel (0.67-x)BiFeO₃-0.33BaTiO₃-x(K_0.5Nd_0.5)TiO₃ (KNT100x, x = 0.0, 0.02, 0.04, 0.06, 0.08 mol%) ceramics were fabricated and their microstructure and electrical properties were studied. All samples displayed a pseudo-cubic symmetry, and adding of KNT had little effect on grain size. The dielectric analysis displayed the dispersion increases with the addition of KNT compositions, showing strong relaxor properties. Besides, high dielectric constant (ε’) of 23000 and dielectric peak temperature (T_m) of 390 °C remain at 1 kHz in the x = 0.02 sample while the dielectric loss (tanδ) dropped below 0.5 in the range of 30–400 °C, showing excellent electrical insulation performance. In addition, doping of KNT had obvious influence on the strain, and a large strain (Smax) of 0.26% was obtained at x = 0.02 due to the increase of electrical insulation. More importantly, the strain at 50 kV cm^?1 enhanced significantly with temperature increasing, reaching a maximum strain of 0.75% with a small hysteresis coefficient of 30% at 110 °C. Particularly, KNT02 exhibited excellent fatigue resistance within 10⁵ fatigue cycles. Presumably these results are attributed to the coexistence of ferroelectric and non-ergodic relaxor domains and the thermally activated domain wall motion.     

Ultra-fast charge-discharge and high energy storage density realized in NaNbO3–La(Mn0.5Ni0.5)O3 ceramics

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(Mn_0.5Ni_0.5)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 W_rec ~1.77 J/cm³ with a high efficiency η = 77% were obtained under the E_b 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.     

Ultrahigh storage density achieved with (1-x)KNN-xBZN ceramics

A series of (1-x)K_0.5Na_0.5NbO₃-xBa(Zn_1/3Nb_2/3)O₃ ((1-x)KNN-xBZN) nanostructural ceramics was successfully synthesised via solid-state reactions. These nanostructural ceramics exhibited high energy storage density compared with pure KNN ceramics. Further analysis of their dielectric/ferroelectric properties and structures revealed that the addition of BZN alloy disrupted the long-range order of the ferroelectric lattice of pure KNN and favoured the formation of ferroelectric islands and/or polar nano-regions. Consequently, the nanostructured ceramic with x = 0.05 exhibited ultrahigh energy storage density, W, of approximately 9.14 J/cm³ and recoverable energy storage density, W_rec, of approximately 4.87 J/cm³ under a fairly low applied electrical field (220 kV/cm). These values exceed the highest values ever reported for KNN-based bulk ceramics. In addition, both excellent fatigue endurance (10⁵ cycles) and temperature stability (Δε'/ε_100°C < 15 % in the range 30–390 °C) were realised with the 0.97KNN-0.03BZN ceramic. Their excellent energy storage properties render KNN-based ceramics potential candidates for application in pulsed-power systems.     

Excellent energy-storage performances in La2O3 doped (Na,K)NbO3-based lead-free relaxor ferroelectrics

Relaxor ferroelectric (FE) materials have received increasing attention owing to their great potentials for energy-storage applications, especially for the ones with high energy-storage density, efficiency and thermal stability simultaneously. A novel lead-free [(Na_0.5K_0.5)_0.97-xLi_0.03](Nb_0.94-xSb_0.06)O₃-xBi(Zn_1/2Zr_1/2)O₃ (NKLNS-xBZZ) ceramics was developed by a solid-state reaction method. The addition of BZZ has induced obvious dielectric relaxation behavior, as well as improved thermal stability of dielectric response. Furthermore, 0.4 wt.% La₂O₃ was added into the NKLNS-0.06BZZ ceramic, leading to an increased breakdown strength as a result of the reduction of grain size, improvement of bulk resistivity and decrease of dielectric loss. A large recoverable energy-storage density (∼4.85 J/cm³) and a high efficiency (∼88.2 %) as well as an excellent thermal stability (±12 %, 25–140 °C) were simultaneously obtained, together with a fast discharge rate (t_0.9∼112 ns). These results suggest that La₂O₃ doped NKLNS-0.06BZZ ceramic could become an attractive dielectric material for temperature-stable energy-storage capacitors.     

Enhanced breakdown strength and energy storage density in a new BiFeO3-based ternary lead-free relaxor ferroelectric ceramic

A new ternary lead-free relaxor ferroelectric ceramic of (0.67-x)BiFeO₃-0.33(Ba_0.8Sr_0.2)TiO₃-xLa(Mg_2/3Nb_1/3)O₃+y wt.% MnO₂+z wt.% BaCu(B₂O₅) (BF-BST-xLMN+y wt.% MnO₂+z wt.% BCB) was prepared by a solid-state reaction method. The substitution of LMN for BF was believed to induce a typical dielectric relaxation behavior owing to the increased random fields. After co-doping MnO₂ and BCB, a significant decrease in the conductivity and grain size was simultaneously realized, resulting in obviously enhanced dielectric breakdown strength and energy-storage performances at room temperature. A high recoverable energy storage density W˜3.38 J/cm³ and an acceptable energy storage efficiency η˜59% were achieved in the composition with x = 0.06, y = 0.1 and z = 2 under a measuring electric field of 23 kV/mm. In addition, the energy-storage performance is quite stable against both frequency (0.1 Hz–100 Hz) and temperature (30–170 °C), suggesting that BF-BST-xLMN+y wt.% MnO₂+z wt.% BCB lead-free relaxor ferroelectric ceramics might be a promising dielectric material for high-power pulsed capacitors.