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The powder samples of (Na0.5Bi0.5)0.705Ba0.045Sr0.25TiO3-xNb2O5 (NBBSNT) were synthesized by a wet solid-phase method. The effects of Nb-doping on morphology, ferroelectric and dielectric properties of samples were investigated. Typical surface morphologies by scanning electron microscopy for the NBTBZN ceramics showed grain size decreasing. Dielectric measurements revealed that the depolarization temperature and Curie temperature shifted to lower temperature. With the increase of Nb content, the ferroelectric hysteresis loops became much slimmer, coupled with the reduction in remnant polarization and coercive field. Energy storage density of 0.855 J/cm3 and the energy storage efficiency of 74.26% were obtained for NBBSNT with x = 0.09. [ABSTRACT FROM AUTHOR]

• A superior discharged energy density of ~ 2.55 J/cm3 and efficiency of ~ 92% values is realized in (BFO-BST)− 0.3SLT ceramic. • The (BFO-BST)-0.3SLT ceramic exhibits impressive temperature stability, fatigue endurance, and frequency stability. • The (BFO-BST)-0.3SLT ceramic shows a high power density (28.11 MW/cm3) and an ultrafast discharge rate (0.0266 μs). Substantial attention for dielectric ceramic capacitors toward lead-free has been driven by the enhanced awareness of environmental protection. However, the unsatisfying breakdown strength (E b) and comparatively low efficiency (η) becomes an obstacle for their widespread application. Here, environment-friendly lead-free relaxor ferroelectric (1-x) (0.67BiFeO 3 -0.33Ba 0.8 Sr 0.2 TiO 3) -xSr 0.7 La 0.2 TiO 3 + 0.1 wt% MnO 2 (BFO-BST-SLT) ceramic is reported as an efficient route to possess excellent E b and high η simultaneously. The doping of SLT can significantly suppress the grain growth, improve the relaxation behavior, and thus increasing the E b and η of the ceramics. Consequently, the corresponding ceramics with x = 0.3 achieves good discharged energy density of ~2.55 J/cm3 and ultrahigh η of ~92%. Notably, it presents outstanding charging/discharging performances with fast charging/discharging time (~0.0266 μs), power density (~28.11 MW/cm3) along with current density (~468.5 A/cm2). Together with great temperature stability, frequency stability and cycle stability, this contributes provides a crucial way to prepare lead-free dielectrics for next-generation pulsed power capacitor applications. [ABSTRACT FROM AUTHOR]

The need for high-performance capacitors that possess superb discharged energy density and efficiency is continually increasing. Relaxor ferroelectric 0.94(0.65Na 0 · 5 Bi 0 · 5 TiO 3 -0.35Sr 0 · 7 Bi 0 · 2 TiO 3)-0.06K 0 · 5 Na 0 · 5 NbO 3 ((NBT-SBT)-KNN) ceramics with different MnO 2 -doping concentrations are prepared in this study. An outstanding discharged energy density (W rec = 3.25 J/cm3) and efficiency (η = 93.8%) are concurrently acquired under 280 kV/cm for these doped ceramics. The ceramics also exhibit extraordinary thermal (30–200 °C), frequency-dependent (1–200 Hz) and fatigue stability (104 st). Additionally, the (NBT-SBT)-KNN-0.08 mol.% MnO 2 ceramic displays a large power density (42 MW/cm3) and an ultrafast discharge speed (98 ns). This contribution offers powerful support for the use of energy storage ceramics in practical applications. [ABSTRACT FROM AUTHOR]

Morphotropic phase (MPB) eco-friendly ferroelectric 0.94Bi 0.5 Na 0.5 TiO 3 - 0.06BaTiO 3 (NBT-BT) ceramics exhibits superior piezoelectric performances. However, the large remnant polarization (P r) and low breakdown strength (E b) of NBT-BT systems hinders application in energy storage capacitors. Herein, the Bi(Zn 1/3 Nb 2/3)O 3 (BZN) is selected to partially replace the NBT-BT ceramics to break ferroelectric long-range order domains achieving higher energy storage properties. Highly recoverable energy storage density (W rec ~ 3 J/cm3) and efficiency (η ~ 75%) are acquired in (NBT-BT)-0.06BZN ceramics under a low applied electric field of 210 kV/cm. Furthermore, superior temperature stability (20–120 °C), and frequency (1–1000 Hz) stability, and fatigue endurance (105 st) are also gained. These advantages further suggest that the (NBT-BT)-0.06BZN ceramics exhibit great promise in pulsed power markets. [ABSTRACT FROM AUTHOR]

• Excellent recoverable energy density (W rec ~ 2.52 J/cm3) and efficiency (η ~ 89.3%) are achieved concomitantly in 0.55NBT-0.45SLTS ceramic. • Both W rec and η of 0.55NBT-0.45SLTS ceramics display excellent temperature stability (20–140 °C), frequency stability (1–1000 Hz) and fatigue endurance (106 cycles). • The 0.55NBT-0.45SLTS ceramics ceramic shows large power density (50.53 MW/cm3) and ultrashort discharge time (<53 ns). Environmental-friendly relaxation ferroelectrics are anticipated as an excellent comprehensive energy storage performance materials due to their near-zero remnant polarization and slim hysteresis loop. Here, the relaxor ferroelectrics (1- x)Na 0.5 Bi 0.5 TiO 3 - x (Sr 0.7 La 0.2)(Ti 0.8 Sn 0.2)O 3 ((1- x)NBT- x SLTS) ceramics with outstanding energy storage performances are synthesized by solid-state reaction. The dielectric properties exhibit obvious frequency dispersion characteristics, and the diffusion coefficient (γ) increases from 1.62 to 1.75 with the doping of SLTS. Also, a large polarization difference (∆ P = 20.08 μC/cm2) and a high breakdown strength (E b = 280 kV/cm) are also achieved simultaneously. As a result, a high recoverable energy density W rec (~ 2.52 J/cm3), together with a satisfactory efficiency η (~ 89.3%), are attained in 0.55NBT-0.45SLTS ceramic. Additionally, the corresponding samples also show satisfactory stability over the wide temperature range of 20–140 °C, with the variables of W rec and η are less than 7% and 2%, respectively. More importantly, this ceramic has an ultrashort discharge time τ 0.9 (53 ns) and a high current density J (721.86 A/cm2). All these results reveal that 0.55NBT-0.45SLTS ceramic is an ideal lead-free next-generation candidate material for pulsed power systems. [ABSTRACT FROM AUTHOR]