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High-performance Sr 0.99 La 0.01 TiO 3 ceramics were synthesized using a conventional solid-phase method, and Sr 0.99 La 0.01 TiO 3 percolated (SLT10-P) samples with excellent resistivity were obtained by coating with an oxidant and heat treatment. In this work, simultaneous excellent dielectric properties (16667 of dielectric permittivity, 0.016 of loss tangent at 1 kHz) and high resistivity (1.44 × 1011 Ω·cm at DC100V) was achieved in SLT10-P ceramics at room temperature by modulating the duration of thermal treatment. X-ray Diffraction and scanning electron microscope analyses proved the diffusion of the oxidant in the grains and grain boundaries during the heat treatment. The increase in grain boundary resistance is mainly due to the fact that the insulating layer formed by the oxide ions entering the grain boundary hinders the long-range movement of electrons. In addition, the diffusion of oxygen from the air into the ceramic during the heat treatment process also contributes to the insulation of grain boundaries. [ABSTRACT FROM AUTHOR]

At present, research on colossal permittivity materials is extensive but challenging to achieve simultaneous properties of colossal permittivity, low loss, and high resistivity. Resistance degradation also restricts industrial application of colossal permittivity materials. In this work, a new method has been proposed to improve resistivity of colossal permittivity ceramics by making metal ions diffuse on ceramic grain boundaries, thus inhibiting the diffusion of oxygen vacancies at grain boundaries. Sr 0.99 La 0.01 TiO 3 (SLT10) ceramics were synthesized by traditional solid-state method, and then Bi 2 O 3 (35%)-Al 2 O 3 (10%)-MgO (20%)-CuO (25%)-SiO 2 (10%) mixed oxidant was selected to percolate into ceramics. The resistivity of SLT10 ceramics improved remarkably (from 2.1×108 Ω cm to 1.23×1011 Ω cm under DC 100 V) with a colossal permittivity (16695 @1 kHz) and a low dielectric loss (0.016 @1 kHz), as well as excellent frequency stability (20 Hz–2 MHz) and temperature stability (-170 °C to 375 °C). The source of high insulation resistivity of the SLT10 ceramic sample was discussed. Subsequent examination uncovered that grain in the SLT10 ceramics percolated with metal ions displayed semiconducting characteristics, wherein insulation grain boundaries significantly influenced the ceramic's resistivity and served as formidable potential barriers constraining long-range movement of charge carriers. Experimental analysis demonstrated that the resistance degradation behavior of the SLT10 ceramics was suppressed, the breakdown voltage was increased, and the service life was extended. [ABSTRACT FROM AUTHOR]

0.75(0.4Na 2 O-0.1K 2 O-0.5Nb 2 O 5)-0.25(0.87SiO 2 -0.13BaO) glass-ceramics were prepared by a traditional melting method to optimize the crystallization kinetics. We obtained a glass network with high degree of polymerization (DOP) by crystallization at different temperatures and achieved a high energy storage density. The increase of crystallization temperature has promoted the precipitation of ferroelectric phases Na 0.9 K 0.1 NbO 3 and NaNbO 3 with high dielectric constant (1200–2000), promoted the increases of grain size from 0.76 μm to 1.33 μm, and reduced the gap width from 3.71eV to 3.22eV. When the crystallization temperature increased to 1000°C–1100 °C, Ba 2 NaNb 5 O 15 with low dielectric constant (∼460) increases, grain boundaries appear, and dielectric constant and BDS decrease. Among all the samples, the sample crystallized at 900 °C showed homogeneous and dense microstructure (grain size∼0.91 μm). The experimental data confirmed that the glass sample crystallized at 900 °C achieves low dielectric loss (<0.005) and high dielectric constant (∼122). The glass sample crystallized at 900 °C sample had a maximum energy storage density of 3.65 J/cm3, a power density of about 54 MW/cm3 and a super-fast discharge speed of 38 ns at 660 kV/cm. [ABSTRACT FROM AUTHOR]

In this study, (1- x)Ca 0.5 Sr 0.5 TiO 3 - x SmNbO 4 ceramics were synthesized using the solid-phase reaction method at 1400 °C. The addition of SmNbO 4 led to significant improvements in breakdown strength (510 kV/cm) and energy storage performance (5.43 J/cm3 and 95.1%), which is the best among linear dielectrics at present. The effects of SmNbO 4 on charge transport and interfacial polarization behavior were investigated. Furthermore, ceramics capacitor exhibits an excellent power density of 36.7 MW/cm3 in an ultrafast discharge time of 29 ns at 140 kV/cm. Meanwhile, x = 0.005 ceramics exhibited good temperature (20 °C–170 °C) and frequency stability (1 Hz–100 Hz). [ABSTRACT FROM AUTHOR]

Herein, the low cost (0.6 − x)BiFeO3–0.4SrTiO3–xBi(Zn0.5Zr0.5)O3 free-lead ceramics can be synthesized via the solid-state reaction methods. The samples have local compositional disorder and constructed small-sized polar nano-regions (PNRs), leading to maximum ΔP (the discrepancy between the maximum polarization (Pmax) and remanent polarization(Pr)) by means of introducing (Zn0.5Zr0.5)3+ at B-site ions in BFO-STO ceramics. Additionally, Bi(Zn0.5Zr0.5)O3(BZZ) could reduce the grain size, enhance the electrical homogeneity and increase energy gap (Eg) of BFO-STO ceramics to reinforce their breakdown strength (BDS). The high recoverable energy-storage density (Wrec = 2.31 J/cm3), good temperature stability (25–120 °C), as well as fast charging and discharging speed (τ0.9 = 31 ns) can be obtained under a high breakdown electric field of 255 kV/cm at x = 0.03. These properties have shown enormous potential in the practical application of pulsed power systems and become promising candidate materials. [ABSTRACT FROM AUTHOR]

A small applied electric field is particularly crucial in the practical application of dielectric ceramic capacitors, since it means a longer lifetime of the capacitors in practical energy storage applications. Based on the traditional ferroelectric BaTiO 3 , the (1- x)(Ba 0.6 Na 0.2 Bi 0.2)TiO 3 - x NaNbO 3 medium-entropy material is designed in this paper, which correlates configuration entropy with energy storage performance. The findings demonstrate that the BNBT-0.15NN ceramic synchronously achieves high energy storage density (2.95 J/cm3) and the energy storage efficiency (95.2%) at 180 kV/cm when the configuration entropy rises to 1.43R. The idea of medium-entropy energy storage under low electric field is proposed for the first time, opening up a new avenue for research into the preparation of high energy storage dielectric ceramics via exploring medium-entropy composition. [ABSTRACT FROM AUTHOR]

It is a great challenge to high colossal permittivity (CP, Ɛ r) in polycrystal ceramics together with low dielectric loss (tanδ) and high insulation resistivity (ρ) due to the miniaturization of electrical devices. In this contribution, the defect dipoles [ T i 4 + • e − C e S r • • − e • T i 4 + ] and [ C e S r • − e • T i 4 + ] have been actively induced in the Sr 1-1.5 x Ce x TiO 3 (SCT) systems by doping Ce ions with amphoteric nature to address this issue. The ultra-stable dielectric performance under the external stimulus, with Ɛ r = 12,406 (with low variation of < ±10%) and tanδ <0.08 , can be achieve in the x = 0.01 sample within the temperature range of 10–200 °C and at the frequencies ranging from 20 Hz to 1 MHz, accompanied by high insulation with ρ > 1010 Ω•cm with low degradation rate under harsh test conditions of 2–4.5 kV/cm. This work paves a path by multisite defect engineering to achieve high-performance CP ceramics. [ABSTRACT FROM AUTHOR]

Effects of annealing atmosphere on the dielectric properties of Sr 1- x Er x TiO 3 ceramics (x = 0–0.014) were systematically investigated in this paper. In x = 0.012 ceramic samples annealed in air, the stable insulation resistivity of over 109 Ω • cm (DC 0–150 V), the CP (16,635 @ 1 kHz, 16,822 @ 1 MHz), and the ultralow dielectric loss (0.006 @ 1 kHz, 0.02 @ 1 MHz) are achieved. Through a thorough examination of dielectric responses, X-ray photoelectron spectroscopy (XPS), UV–visible absorption spectrum, and complex impedance data, it is demonstrated that the defect dipoles [ Ti Ti ′ − V O ·· − Ti Ti ′ ] , [ Er Sr · − Ti Ti ′ ] , [ 2 Er Ti ′ − V O ·· ] , [ Ti Ti ′ − V O · ] , [ Er Ti ′ − V O · ] and [ Er Sr · − Er Ti ′ ] form in Sr 1- x Er x TiO 3 (when x = 0.012) ceramic annealed under flowing air. We innovatively used variable temperature in situ resistance monitoring equipment to simulate the industrial environment, the insulating properties and the microscopic mechanism of oxygen vacancy diffusion of ceramics were investigated under different voltages and temperatures, which is of great significance to achieve more desirable colossal permittivity, ultra-low dielectric loss and insulation resistivity performance for real applications. • The correlation between oxygen vacancy diffusion and temperature is monitored in real time by using temperature variable in situ resistance monitoring equipment. • The insulating properties and the microscopic mechanism of oxygen vacancy diffusion of ceramics were investigated under different voltages and temperatures under simulated industrial environment. • The reoxidation grain boundary method was used to increase the grain boundary resistivity, so as to increase the overall resistivity of ceramics. High-quality and excellent overall performance SET12-N-Air ceramic materials were successfully prepared. [ABSTRACT FROM AUTHOR]

• Superior recoverable energy density of 7.92 J/cm3 and efficiency of 94.3% are attained. • Sm 2 O 3 doped in pure CST ceramic can form Sm A Â · - 3 Ti Ti ′ - V O Â · Â · to optimize E b from 300 kV/cm to 630 kV/cm −660 kV/cm. • The CSST3 ceramic shows excellent thermal stability and frequency stability. In the realm of energy storage, there is an exigent need for dielectric materials that exhibit high energy storage density (W rec) and efficiency (η) over wide temperature ranges. Linear dielectrics exhibit superior breakdown strength (E b) compared to ferroelectrics, yet their utility is restricted by low polarization. Here, an ultrahigh W rec up to 7.92 J/cm3 and η ≈ 94.3% are realized in (Ca 0.5 Sr 0.5)1-1.5 x Sm x TiO 3 ceramic with ultrafast discharge time (t 0.9 = 20 ns) which is one of the best energy storage performances recorded linear ceramics. By employing the charge balance method, the production of oxygen vacancies (V O Â · Â · ) can be prevented, leading to improved insulation. The creation of A-site vacancies serves to enhance the breakdown field strength. Furthermore, the incorporation of Sm3+ effectively limits the thermal activation of oxygen vacancies at elevated temperatures, ultimately resulting in an increase in bulk resistivity. The results also unveil the outstanding stability across a wide range of temperatures (20 °C–140 °C) and frequencies (1 Hz–500 Hz). Consequently, this study provides significant insights into enhancing E b and attaining high-energy storage capacitors. [ABSTRACT FROM AUTHOR]

• The introduction of Na 2 O reduces the fracture degree of [BO 3 ] and makes the glass network structure tend to compact to obtain high breakdown strength. • The excellent dielectric properties (ε r = 158, tanδ ≤ 0.04) are obtained by crystal phase species regulation under the premise of relatively high breakdown performance(490 kV/cm). • The 0.9(0.5K 2 O-0.5Na 2 O-Nb 2 O 5)-0.1B 2 O 3 glass-ceramic achieved high actual energy-storage density (0.09 J/cm3) and fast charging and discharging speed (τ 0.9 = 15 ns). To reduce carrier mobility and optimize crystal phase species, 0.9((1- x)K 2 O- x Na 2 O-Nb 2 O 5)-0.1B 2 O 3 glass-ceramics were prepared by the traditional melting method. By introducing Na 2 O, Na 0.9 K 0.1 NbO 3 ferroelectric phase increases, and the "rice-like" morphology grains transfer to the cubic grains gradually. As the radius of Na+ is smaller than K+, the ability of Na+ to provide free oxygen is weaker, which reduces the fracture degree of [BO 3 ] and makes the glass network structure tend to compact. As a result, the stable high permittivity (158) and low dielectric loss (tanδ ≤ 0.04) are obtained in the broad frequency range (20 Hz to 1 MHz) and temperature range (25–200 °C). In addition, these samples also reveal a relatively high energy-storage density (1.64 J/cm3) under breakdown strength (490 kV/cm), which is mainly attributed to the dense glass network and optimized crystalline phase. Pulse discharge testing further verifies that the 0.9(0.5K 2 O-0.5Na 2 O-Nb 2 O 5)-0.1B 2 O 3 glass-ceramic achieves high actual energy-storage density (0.09 J/cm3) at lower electric field strengths, and fast charging and discharging speed (τ 0.9 = 15 ns). [ABSTRACT FROM AUTHOR]