Bi(Al0.5Sc0.5)O3增强BaTiO3陶瓷弛豫铁电及储能性能

Enhanced Relaxor Ferroelectrics and Energy Storage of BaTiO3-based Ceramics Modified by Bi(Al0.5Sc0.5)O3

设计并合成了一种无铅改性BaTiO3基储能陶瓷,通过固相反应法制备了无铅单相钙钛矿BaTiO3–Bi(Al0.5Sc0.5)O3陶瓷,研究了掺杂不同含量BAS对陶瓷的结构、介电性能、铁电性能及储能特性的影响。结果表明:(1–x)BT–x BAS固溶体从四方相(x≤0.05)转变为部分立方相(x≥0.1),但仍以四方相为主且细晶化;随着其含量的增加,Curie温度(Tm)向低温方向移动并出现了介电峰宽化,表现出明显的介电色散行为;BAS的引入破坏了BT陶瓷铁电畴的长程有序,发生了铁电相到弛豫铁电相的相变;2种现象均表明BT–BAS陶瓷具有弛豫铁电体的优异特点。在所有样品中,0.85BT–0.15BAS陶瓷的介电温度稳定性最佳,弛豫因子γ为1.97;外加电场~105 k V/cm时,储能密度为0.684 J·cm–3,储能效率为95.0%,陶瓷具有最佳储能特性。

Lead-free single-phase perovskite BaTiO3–Bi(Al0.5Sc0.5)O3 ceramics as novel high performance BaTiO3-based energy storage ceramics were synthesized by a solid-state reaction method.Effect of BAS content on the structure,dielectric properties,energy storage of(1–x)BT–x BAS ceramics was investigated.The(1–x)BT–x BAS solid solution transforms from tetragonal(x≤0.05)to cubic(x≥0.1),but is still based on the tetragonal.The Tm moves toward a low temperature range,and the dielectric peak broadens with the BAS content increases,exhibiting a dispersive dielectric behavior with respect to frequency.The long-range ferroelectric order of ceramics is destroyed by BAS.Also,the phase transition of BT–x BAS ceramics is from a typical ferroelectric phase to a relaxor phase.The phenomena both indicate that the BT–BAS ceramics could have the excellent characteristics of relaxor ferroelectrics.The 0.85 BT–0.15 BAS ceramics show a good temperature stability,and the diffusion coefficientγis 1.97.There are an energy storage density of 0.684 J·cm–3 and an energy efficiency of 95%in an electric field of about 105 kV/cm.