Improved Breakdown Strength in(Ba_(0.6)Sr_(0.4))_(0.85)Bi_(0.1)TiO_3 Ceramics with Addition of CaZrO_3 for Energy Storage Application

（Ba（0.6） Sr（0.4））（0.85） Bi（0.1） TiO3 ceramics doped with x wt%CaZrO3（x= 0-10） were synthesized by solid-state reaction method. The effects of CaZrO3 amount on the dielectric properties and structure of（Ba（0.6）Sr（0.4））（0.85） Bi（0.1） TiO3 ceramics were investigated. X-ray diffraction results indicated a pure cubic perovskite structure for all samples and that the lattice parameter increased till x=5 and then slightly decreased. A homogenous microstructure was observed with the addition of CaZrO3. Dielectric measurements revealed a relaxor-like characteristic for all samples and that the diffusivity γ reached the maximum value of 1.78 at x=5. With the addition of CaZrO3, the dielectric constant dependence on electric field was weakened, insulation resistivity enhanced and dielectric breakdown strength improved obviously and reached 19.9 k V/mm at x=7.5. In virtue of low dielectric loss（tan d〈0.001 5）, moderate dielectric constant（er 〉1 500） and high breakdown strength（Eb 〉17.5 k V/mm）, the CaZrO3 doped（Ba（0.6）Sr（0.4））0.85 Bi（0.1） TiO3 ceramic is a potential candidate material for high power electric applications.

Superior energy storage performance of BNT-based ferroelectric ceramics based on maintaining high polarization and breakdown strength

Bi_(0.5)Na_(0.5)TiO_(3)(BNT)-based lead-free ceramics with superior ferroelectric properties are considered to be extremely advantageous in energy storage capacitors for future green technologies.Here,we demonstrate an approach to achieve both ultrahigh energy density W_(rec)and efficiencyηby regulating the multiscale electropolar structures and microstructure.A satisfactory energy storage performance of a high W_(rec)of 4.02 J·cm^(-3),and a decentηof 80%under 415 kV·cm^(-1)are attained in the 0.5(BNT-CS)-0.5SB_(0.2)T ceramic(abbreviated as BNT-0.2SBT).Moreover,BNT-0.2SBT exhibits superior power density(P_(D)=107MW·cm^(-3)),ultrafast discharge time(t_(0.9)=116 ns)at 150 kV·cm^(-1),and good temperature stability.The findings in this work not only demonstrate that a valid candidate,but also provide a new idea of how to achieve both high-energy storage density and efficiency in lead-free ferroelectric materials.

(Bi_(0.51)Na_(0.47))TiO_(3) based lead free ceramics with high energy density and efficiency

Dielectric ceramics with high energy storage density and energy efficiency play an important role in high power energy storage applications.In this work,lead free relaxor ferroelectric ceramics in (1-x) Bi_(0.51)Na_(0.47)TiO_(3-x)Ba(Zr_(0.3)Ti_(0.7))O_(3)(BNT-BZT100x:x=0.20,0.30,0.40 and 0.50)system are fabricated by conventional solid-state sintering method.The BNT-BZT100x ceramics are sintered dense with minimal pores,exhibiting pseudocubic symmetry and strong relaxor characteristic.A high energy storage density of 3.1 J/cm^(3) and high energy efficiency of 91% are simultaneously achieved in BNT-BZT40 ceramic with 0.1mm in thickness,at the applied electric field of 280 kV/cm.The temperature stability of the energy density is studied over temperature range of 20-160℃ ,showing minimal variation below 1.5%,together with the excellent cycling reliability(the variations of both energy density and efficiency are below 3% up to 106 cycles),making BNT-BZT40 ceramic promising candidate for high-temperature dielectric and energy storage applications.