High permittivity and excellent high‐temperature energy storage properties of X9R BaTiO₃–(Bi_0.5Na_0.5)TiO₃ ceramics

Abstract

We fabricated x(Bi0.5Na0.5)TiO3–(1−x)[BaTiO3–(Bi0.5Na0.5)TiO3–Nb] (BNT‐doped BTBNT‐Nb) dielectric materials with high permittivity and excellent high‐temperature energy storage properties. The initial powder of Nb‐modified BTBNT was first calcined and then modified with different stoichiometric ratios of (Bi0.5Na0.5)TiO3 (BNT). Variable‐temperature X‐ray diffraction (XRD) results showed that the ceramics with a small amount of BNT doping consisted of coexisting tetragonal and pseudocubic phases, which transformed into the pseudocubic phase as the test temperature increased. The results of transmission electron microscopy (TEM) showed that the ceramic grain was the core‐shell structure. The permittivity of the 5 mol% BNT‐doped BTBNT‐Nb ceramic reached up to 2343, meeting the X9R specification. The discharge energy densities of all samples were 1.70‐1.91 J/cm3 at room temperature. The discharge energy densities of all samples fluctuated by only ±5% over the wide temperature range from 25°C to 175°C and ±8% from 25°C to 200°C. The discharge energy density of the 50 mol% BNT‐doped BTBNT‐Nb ceramic was 2.01 J/cm3 at 210 kV/cm and 175°C. The maximum energy efficiencies of all ceramics were up to ~91% at high temperatures and were much better than those at room temperature. The stable dielectric properties within a wide temperature window and excellent high‐temperature energy storage properties of this BNT‐doped BTBNT‐Nb system make it promising to provide candidate materials for multilayer ceramic capacitor applications.

Enhanced energy storage properties in BNT-based ceramics with a morphotropic phase boundary modified by Sr(Mg1/3Nb2/3)O3

“…9 compares the energy storage efficiency and recoverable energy storage density of various lead-free ceramics that have potential for applications under medium-low electric fields. [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] It can be seen that compared with other lead-free ceramics, 0.85BBNKT-0.15SMN ceramic has certain advantages over other lead-free ceramics in terms of overall energy storage performance.…”

KNN based high dielectric constant X9R ceramics with fine grain structure and energy storage ability

“…Core-shell structure with fingerprint-like nanodomains as core parts can be detected, as shown in the circled sites, but are not ubiquitous as typical core-shell structured systems such as BaTiO 3 based ceramics. 2,4 The relatively large | 5819 doping amount of the SrZrO 3 can lead to a large volume ratio of the shell part, causing the core part with ferroelectric domain stripes to be compressed to nanoscale. In addition, the detection of ferroelectric stripes in bright-field TEM image mode depends on the interaction angle between the incident electrons and the sample; therefore, the core-shell structure is not generally observed in every grain.…”

“…Capacitors are widely used in industries such as aerospace and aviation, deep oil drilling, and the automotive industry, where the electronic equipment is usually subjected to high working temperatures. 1,2 For example, the temperature of the engine bay can reach approximately 150°C and the antiblock system is required to function from 150°C to 250°C in automotive industry. 1 In general, temperature-stable dielectric materials are critical for future development of these industries.…”

Boosting dielectric temperature stability in BNBST‐based energy storage ceramics by Nb2O5 modification

“…Many studies have shown that adding a small amount of Nb 2 O 5 can suppress the dielectric peak of BNT-based ceramics and shift T m downward to low temperature, achieving TCC ± 0.15 standard in a wide temperature range. [35][36][37][38][39][40][41] Based on the above considerations, it is logical to explore Nb 2 O 5 addition in our previous optimized Ce 4+ -doped BNBST ceramics for boosting dielectric temperature stability and energy storage properties. x wt%Nb 2 O 5 , x = 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0) ceramics by a solid-state reaction method.…”

“…However, its relatively low recoverable energy density ( W rec ∼ 1.15 J/cm 3 ) needs to be further increased, and the window of temperature stability also needs to be further widened. Many studies have shown that adding a small amount of Nb 2 O 5 can suppress the dielectric peak of BNT‐based ceramics and shift T m downward to low temperature, achieving TCC ± 0.15 standard in a wide temperature range 35–41 . Based on the above considerations, it is logical to explore Nb 2 O 5 addition in our previous optimized Ce 4+ ‐doped BNBST ceramics for boosting dielectric temperature stability and energy storage properties.…”