Multi-objective collaborative design optimized highly efficient energy capacitive lead-free relaxor ferroelectrics

Abstract

Cutting-edge energy storage ceramics as the core components in pulse power capacitors are indispensable for advanced electronic systems. Although improved energy-storage performance has been realized to a certain extent, how...

Excellent Energy Storage Performance Achieved in Sr(Sc0.5Nb0.5)O3-Doped Bi0.5Na0.5TiO3-Based Lead-Free Relaxor Ferroelectric Ceramics

“…This can efficiently decrease P r and delay the saturation of polarization. 21,45 A properly adjusted R/T phase ratio can balance P max , P r , and E b to produce an excellent ESP.…”

“…The highly dynamic T phase shows less hysteresis under the applied electric field than the R phase. This can efficiently decrease P r and delay the saturation of polarization. , A properly adjusted R / T phase ratio can balance P max , P r , and E b to produce an excellent ESP.…”

“…According to previous reports, BNT exhibits a rhombohedral ( R , space group R 3 c ) phase structure below 255 °C, while the R phase in BNT gradually transforms into a tetragonal ( T , space group P 4 bm ) phase between 255 and 400 °C, forming a two-phase structure in which the R phase coexists with the T phase. − The R phase of BNT typically possesses high polarization, but there is a large polarization hysteresis under electric field action, causing BNT to exhibit square P – E hysteresis loops at ambient temperature. , In contrast, the T phase of BNT exhibits comparatively low polarization and high dynamic activity with small polarization hysteresis under electric field action . The modulated phase structure of BNT through component optimization design has become an effective strategy to improve ESP. ,,, …”

“…21 The modulated phase structure of BNT through component optimization design has become an effective strategy to improve ESP. 9,21,27,28 Dielectric ceramic materials depend on the polarization and depolarization process driven by an electric field to attain energy storage. 12 The special mechanism results in very fast charge/discharge rates.…”

“…The E b of ceramic materials can be optimized by adjusting grain size, thickness, and dense property, as it is primarily related to their highly insulating grain boundaries. ,, Currently, enhancing E b can be achieved through grain refinement, , introducing high band gap ( E g ) compositions, , and optimizing thickness processes. , For example, Wang et al introduced BiScO 3 into BNST, which significantly diminished the grain size from 2.81 to 0.71 μm and boosted the E b from 185 to 480 kV·cm –1 . Lin et al introduced NaTaO 3 ( E g ∼ 4.1 eV) into the binary matrix BNT-BAT, which significantly reduced the grain size while increasing the E g , resulting in an improvement in E b from 240 to 420 kV·cm –1 . Wang et al obtained an E b of 410 kV·cm –1 in BNST- x NaNbO 3 by a viscous polymer process that significantly reduced grain size and increased compactness …”