Dielectric ceramics have attracted extensive attention for high-power energy storage applications due to their fast charge-discharge capabilities and high power density.Bi_(0.5)Na_(0.5)TiO_(3)(BNT)-based lead-free cer...Dielectric ceramics have attracted extensive attention for high-power energy storage applications due to their fast charge-discharge capabilities and high power density.Bi_(0.5)Na_(0.5)TiO_(3)(BNT)-based lead-free ceramics are notable for their high saturation polarization and moderate breakdown electric field(Eb),but they still suffer from a low breakdown field,large hysteresis losses and insufficient efficiency.Here,we propose a strategy of dual-site ion-pair engineering by introducing Ba(Sr_(0.5)W_(0.5))O_(3)(BSW)into the BNT matrix.In this design,Ba^(2+)-Ba^(2+)pairs at the A-site and Sr^(2+)-W^(6+)pairs at the B-site induce local lattice distortion and generate strong random fields,which effectively promote the formation of multiple relaxor phases with polymorphic nanodomains.The features of electrical properties and phase-field simulations indicate that BSW doping facilitates greater compositional disorder and disruption of long-range FE order,integrating the short-range ordered antiferroelectric(AFE)nanodomains with highly disordered relaxor ferroelectric(RFE)regions to reduce the electric field-induced AFE-FE phase transition barrier.Additionally,the incorporation of BSW refines the grain size and increases microstructural homogeneity,enhancing the breakdown strength and delaying the polarization saturation.Accordingly,the 0.90BNT-0.10BSW ceramic exhibited an outstanding energy storage performance with a high W_(rec) of 6.57 J cm^(-3) and anηof 72%under an electric field of 450 kV cm^(-1).In addition,the ceramic synchronously possesses an excellent transient discharge rate t0.9 of 90 ns and a high power density PD of 121.9 MW cm^(-3).This work suggests that dual-site ion-pair engineering is an effective approach for regulating structure-property relationships in BNT-based ceramics and provides a viable pathway for the development of high-performance lead-free dielectric materials for advanced energy storage applications.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52202142)the Science and Technology Serving Enterprise Project in Universities and Colleges of Xi’an Science and Technology Bureau(Grant No.24GXFW0002)the Natural Science Basic Research Program of Shaanxi Province(Grants No.2025JC-YBMS-133 and 2023-JC-QN-0066).
文摘Dielectric ceramics have attracted extensive attention for high-power energy storage applications due to their fast charge-discharge capabilities and high power density.Bi_(0.5)Na_(0.5)TiO_(3)(BNT)-based lead-free ceramics are notable for their high saturation polarization and moderate breakdown electric field(Eb),but they still suffer from a low breakdown field,large hysteresis losses and insufficient efficiency.Here,we propose a strategy of dual-site ion-pair engineering by introducing Ba(Sr_(0.5)W_(0.5))O_(3)(BSW)into the BNT matrix.In this design,Ba^(2+)-Ba^(2+)pairs at the A-site and Sr^(2+)-W^(6+)pairs at the B-site induce local lattice distortion and generate strong random fields,which effectively promote the formation of multiple relaxor phases with polymorphic nanodomains.The features of electrical properties and phase-field simulations indicate that BSW doping facilitates greater compositional disorder and disruption of long-range FE order,integrating the short-range ordered antiferroelectric(AFE)nanodomains with highly disordered relaxor ferroelectric(RFE)regions to reduce the electric field-induced AFE-FE phase transition barrier.Additionally,the incorporation of BSW refines the grain size and increases microstructural homogeneity,enhancing the breakdown strength and delaying the polarization saturation.Accordingly,the 0.90BNT-0.10BSW ceramic exhibited an outstanding energy storage performance with a high W_(rec) of 6.57 J cm^(-3) and anηof 72%under an electric field of 450 kV cm^(-1).In addition,the ceramic synchronously possesses an excellent transient discharge rate t0.9 of 90 ns and a high power density PD of 121.9 MW cm^(-3).This work suggests that dual-site ion-pair engineering is an effective approach for regulating structure-property relationships in BNT-based ceramics and provides a viable pathway for the development of high-performance lead-free dielectric materials for advanced energy storage applications.
