Dielectric ceramic capacitors have attracted significant interest in advanced pulsed power systems owing to their ultrahigh power density and fast charge/discharge capabilities. The low breakdown strength(E_(b)) of di...Dielectric ceramic capacitors have attracted significant interest in advanced pulsed power systems owing to their ultrahigh power density and fast charge/discharge capabilities. The low breakdown strength(E_(b)) of dielectric ceramics poses a major bottleneck for achieving high recoverable energy storage density(W rec). In this study, using ingenious chemical component design, we achieved an ultrahigh Eb of 800 kV/cm and an excellent W rec value of 9.48 J/cm^(3) in the simple component 0.92NaNbO_(3)–0.08SmFeO_(3) ceramic. Finite element simulations corroborate that the optimized grain boundary network enables more uniform electric field distribution and effective suppression of breakdown propagation. The superior energy storage characteristics originate from two synergistic mechanisms:(Ι) the incorporation of SmFeO_(3) suppresses grain growth, resulting in refined microstructure with increased grain boundary density that substantially enhances E_(b);(II) the introduction of Sm^(3+) and Fe^(3+) ions causes a mismatch between the A/B site ions, inducing lattice distortion and high disorder, which enhances the local random fields and relaxor behavior. This study establishes a promising pathway for designing high-energy-density dielectric ceramic capacitors.展开更多
电子工业发展使多层陶瓷电容器的需求大增,为降低成本,适用于贱金属电极的介质陶瓷成为研究热点。选择MnO_(2)掺杂0.95Ba Ti O3–0.05Bi Co O3陶瓷,经调整掺杂比例,其抗还原与介电性能大幅提升。结果表明:还原气氛下Mn离子变价使晶胞体...电子工业发展使多层陶瓷电容器的需求大增,为降低成本,适用于贱金属电极的介质陶瓷成为研究热点。选择MnO_(2)掺杂0.95Ba Ti O3–0.05Bi Co O3陶瓷,经调整掺杂比例,其抗还原与介电性能大幅提升。结果表明:还原气氛下Mn离子变价使晶胞体积膨胀,形成不均匀结构使Curie峰分裂并展宽,介温稳定性提高,x=0.5时性能最佳,ε(25℃)=2354,tanδ=0.0075,稳定性符合X8R。同时,元素变价的过程有助于降低电子浓度,电阻率提高至1.84×10~(13)Ω·cm,最大耐压达到210 k V/cm。热激励退极化漏电流测试表明Co、Mn结合氧空位形成缺陷偶极,进一步增强抗还原性能。展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.52462018,52162019)the Key Project of the Natural Science Foundation of Jiangxi Province (Grant No.20252BAC250038)the Science Fund for Distinguished Young Scholars of Jiangxi Province (Grant No.20224ACB214007)。
文摘Dielectric ceramic capacitors have attracted significant interest in advanced pulsed power systems owing to their ultrahigh power density and fast charge/discharge capabilities. The low breakdown strength(E_(b)) of dielectric ceramics poses a major bottleneck for achieving high recoverable energy storage density(W rec). In this study, using ingenious chemical component design, we achieved an ultrahigh Eb of 800 kV/cm and an excellent W rec value of 9.48 J/cm^(3) in the simple component 0.92NaNbO_(3)–0.08SmFeO_(3) ceramic. Finite element simulations corroborate that the optimized grain boundary network enables more uniform electric field distribution and effective suppression of breakdown propagation. The superior energy storage characteristics originate from two synergistic mechanisms:(Ι) the incorporation of SmFeO_(3) suppresses grain growth, resulting in refined microstructure with increased grain boundary density that substantially enhances E_(b);(II) the introduction of Sm^(3+) and Fe^(3+) ions causes a mismatch between the A/B site ions, inducing lattice distortion and high disorder, which enhances the local random fields and relaxor behavior. This study establishes a promising pathway for designing high-energy-density dielectric ceramic capacitors.
文摘电子工业发展使多层陶瓷电容器的需求大增,为降低成本,适用于贱金属电极的介质陶瓷成为研究热点。选择MnO_(2)掺杂0.95Ba Ti O3–0.05Bi Co O3陶瓷,经调整掺杂比例,其抗还原与介电性能大幅提升。结果表明:还原气氛下Mn离子变价使晶胞体积膨胀,形成不均匀结构使Curie峰分裂并展宽,介温稳定性提高,x=0.5时性能最佳,ε(25℃)=2354,tanδ=0.0075,稳定性符合X8R。同时,元素变价的过程有助于降低电子浓度,电阻率提高至1.84×10~(13)Ω·cm,最大耐压达到210 k V/cm。热激励退极化漏电流测试表明Co、Mn结合氧空位形成缺陷偶极,进一步增强抗还原性能。
