电子元件与材料2025，Vol.44Issue(4)：368-376,383,10.DOI:10.14106/j.cnki.1001-2028.2025.1494
Sn4+、Nb5+共掺BNT-SBT陶瓷的储能特性及其稳定性
Energy storage characteristics and stability of Sn4+and Nb5+co-doped BNT-SBT ceramics
摘要
Abstract
To address the critical demands for advanced dielectric materials in next-generation pulsed power capacitors,BNT-based ceramics have emerged as promising lead-free candidates due to their high energy storage density and eco-friendliness.However,their practical application is limited by the insufficient temperature-frequency stability under extreme operating conditions.Here 0.6(Na0.5Bi0.5)TiO3-0.4(Sr0.7Bi0.2)TiO3-x％SnNb2O7(BNT-SBT-x％SN,x=0.2-1.2)ceramics were prepared by the conventional solid-state method.The effects of the Sn4+/Nb5+co-dopant were systematically investigated on the structural evolution,dielectric/ferroelectric properties,strain behavior,and particular the energy storage characteristics and their stability.The results show that all samples have perovskite structure.Moderate doping(x＜0.6)could induce unit cell contraction through Sn4+/Nb5+substitution,while excessive doping(x≥0.6)could trigger the formation of the Bi2Ti2O7 secondary phase.The local structural disorder could be generated by the disruption of long-range ferroelectric order due to the heterovalent A/B-site co-occupancy,which establishes weakly coupled polar nanoregions(PNRs)and pronounced relaxor behavior(1.89＜γ＜2.07).The optimal composition(x=0.4)exhibits superior dielectric stability from 30 to 300 ℃(-15％＜△εr/εr(150℃)＜+5％),achieving a energy storage density W,=0.8048 J/cm3(△P=26.23 μC/cm2)and efficiency of η=81.06％.Remarkably,W,and η variations are smaller than 15％and 4％,respectively between 30 and 180 ℃,and their frequency-dependent fluctuations are also limited below 5％(W1)and 6.9％(η)from 1 to 50 Hz.This stability originates from the dynamic polarization response of the PNRs under external perturbations without significant phase transitions.This work demonstrates that A/B-site synergistic engineering via Sn4+/Nb5+co-doping could effectively balance the relaxor behavior and stability,which offers a viable material platform for wide-temperature/frequency-adaptive lead-free energy storage devices.关键词
BNT陶瓷/Sn4+/Nb5+/弛豫特性/储能特性/稳定性Key words
BNT ceramics/Sn4+/Nb5+/relaxation characteristics/energy storage characteristics/stability分类
信息技术与安全科学引用本文复制引用
肖齐龙,刘洋,黄椿,吴文娟,曾体贤..Sn4+、Nb5+共掺BNT-SBT陶瓷的储能特性及其稳定性[J].电子元件与材料,2025,44(4):368-376,383,10.基金项目
国家自然科学基金(12474091,12374089) （12474091,12374089）
四川省科技厅项目(2023ZYD0175) （2023ZYD0175）
