Ultra-High Energy Storage Performance in BNT-based Ferroelectric Ceramics with Simultaneously Enhanced Polarization and Breakdown Strength

Abstract

BNT (Bi 0.5 Na 0.5 TiO 3 )-based ferroelectric ceramics have drawn much attention in energy storage applications due to the high saturation polarization and good temperature stability. However, the reduction of Ti 4+ caused by the volatilization of Bi and Na elements during high-temperature sintering is a huge problem. A multivalent element (Mn) is adopted in this work to prevent the reduction of Ti 4+ and thus enhance the polarization and breakdown strength simultaneously. Various contents of MnO 2 -doped 0.76Bi 0.5 Na 0.5 TiO 3 −0.04SrZrO 3 −0.2NaNbO 3 (BNTSZNN) ceramics were prepared by the ramp-to-spike sintering method. As the content of MnO 2 increases, the reduction of Ti 4+ is effectively decreased, inhibiting the degradation of ferroelectricity and decreasing the leakage conductance. As a result, an ultra-high discharge energy density of 7.05 J/cm 3 is achieved in the BNTSZNN-0.15MnO 2 ceramic at 387 kV/cm. Importantly, the BNTSZNN-0.15MnO 2 ceramic shows excellent temperature stability. The change of the discharge energy density between 30 and 160 °C is less than ±4% under the applied field of 120 kV/cm. Additionally, the variation in the capacitance of the BNTSZNN-0.15 MnO 2 ceramic is less than ±15% over the temperature range from −58 to 450 °C, with a high room-temperature dielectric permittivity of 1507. All the above characteristics indicate the potential of BNTSZNN-0.15MnO 2 as a high-temperature and high-voltage ceramic dielectric.

Simultaneously enhanced energy density and discharge efficiency of (Na0.5Bi0.5)0.7Sr0.3TiO3-La1/3(Ta0.5Nb0.5)O3 lead-free energy storage ceramics via grain inhibition and dielectric peak flattening engineering

“…8(d). Compared with NN-based, 47,48 BNT-based, [49][50][51][52][53][54][55][56] BT-based [57][58][59] and BF-based 60,61 ceramics under analogously low electric fields, the BNST-0.025LTN ceramic exhibits an appreciable W rec accompanied by an ultrahigh η. Obviously, the present study tenders an effective strategy to obtain a simultaneous elevation of W rec and η at low electric fields, which is competitive in practical applications of dielectric materials.…”

Achieving High Energy Storage Performance under a Low Electric Field in KNbO3-Doped BNT-Based Ceramics

“…The Nb 5+ ions in KNbO 3 help to hinder the migration of oxygen vacancies, which increases the resistivity and reduces the Ti 4+ reduction. Thus, the P max value remains at a high value due to the inhibition reduction of Ti 4+ , , for the x = 0.2 sample. Furthermore, for samples with x > 0.2, the decrease in the P max value is due to the random distribution of the relaxation phase, which inhibits the switching of nanodomains .…”

Ultrahigh energy storage density, high efficiency and superior thermal stability in Bi0.5Na0.5TiO3-based relaxor ferroelectric ceramicsviaconstructing multiphase structures

“…2(a-e). 9,14,22,23 And the relatively low reliability factors shown in Table S1 † suggest that the renement results are dependable. Aer incorporating BSZS, the phase structure of ceramics transforms from R3c into the coexistence of R3c and P4bm.…”

“…3(d)), respectively, reveals the improved relaxor behavior owing to the emergence of weakly coupled PNRs. (3) With increasing x, the permittivity curves become more and more attened, indicating improved thermal stability of 3 r , which is generally described by the temperature coefficient of capacitance (TCC) according to the equation: 22,26,27 TCC = 3 r − 3 150 °C/3 150 °C, where 150 °C is the base temperature. As shown in Fig.…”