A high breakdown strength(E_(b))together with a large maximum polarization(P_(m))is essential for achieving a high recoverable energy density(W_(rec))in energy storage dielectric ceramics.However,meeting the urgent ne...A high breakdown strength(E_(b))together with a large maximum polarization(P_(m))is essential for achieving a high recoverable energy density(W_(rec))in energy storage dielectric ceramics.However,meeting the urgent need for practical applications remains a challenge due to the intrinsic properties of bulk dielectric ceramics.Herein,a composition and structure optimization strategy combined with a two-step sintering(TSS)process is proposed to design and fabricate(1−x)Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.9)O_(3−x)Bi(Mg_(1/2)Sn_(1/2))O_(3)(BCZT-BMSx-TSS)lead-free ceramics.Highly dynamic locally polar nano-regions(PNRs)are formed via composition optimization,exhibiting a very high P_(m) and energy storage efficiency(η).Compared to the traditional one-step sintering(OSS)process,the TSS process results in a composition with finer grain size and higher density,dramatically increasing E_(b).As a result,an ultrahigh energy storage performance with W_(rec)∼10.53 J cm^(−3) and η∼85.71%is achieved for the BCZT-BMSx-TSS(x=0.08)ceramic which is attributed to a record high E_(b)∼830 kV cm^(−1) and a large P_(m)∼44.66μC cm^(−2).Complex impedance spectroscopy revealed that the activation energies of the bulk and grain boundary counterparts significantly increased,suggesting an increase in insulation resistance and a decrease in oxygen vacancies,which is the main reason for the high E_(b) value.In addition,excellent thermal/frequency stability is achieved in both energy density and efficiency,along with good charge–discharge performance.These findings suggest that BCZT-based lead-free ceramics have the potential for practical use in the future.展开更多
基金supported by the Projects of the Jilin Provincial Science and Technology Department(Grant No.YDZJ202201ZYTS420)the Projects of the Jilin Provincial Education Department(Grant No.JJKH20230298KJ)the National Science Foundation for Yong Scientists China(Grant No.62004081).
文摘A high breakdown strength(E_(b))together with a large maximum polarization(P_(m))is essential for achieving a high recoverable energy density(W_(rec))in energy storage dielectric ceramics.However,meeting the urgent need for practical applications remains a challenge due to the intrinsic properties of bulk dielectric ceramics.Herein,a composition and structure optimization strategy combined with a two-step sintering(TSS)process is proposed to design and fabricate(1−x)Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.9)O_(3−x)Bi(Mg_(1/2)Sn_(1/2))O_(3)(BCZT-BMSx-TSS)lead-free ceramics.Highly dynamic locally polar nano-regions(PNRs)are formed via composition optimization,exhibiting a very high P_(m) and energy storage efficiency(η).Compared to the traditional one-step sintering(OSS)process,the TSS process results in a composition with finer grain size and higher density,dramatically increasing E_(b).As a result,an ultrahigh energy storage performance with W_(rec)∼10.53 J cm^(−3) and η∼85.71%is achieved for the BCZT-BMSx-TSS(x=0.08)ceramic which is attributed to a record high E_(b)∼830 kV cm^(−1) and a large P_(m)∼44.66μC cm^(−2).Complex impedance spectroscopy revealed that the activation energies of the bulk and grain boundary counterparts significantly increased,suggesting an increase in insulation resistance and a decrease in oxygen vacancies,which is the main reason for the high E_(b) value.In addition,excellent thermal/frequency stability is achieved in both energy density and efficiency,along with good charge–discharge performance.These findings suggest that BCZT-based lead-free ceramics have the potential for practical use in the future.
