为提升钛酸铋钠(NBT)基无铅陶瓷电容材料的储能性能,以A位掺杂方式向0.65[Na_(0.5)Bi_(0.5)TiO_(3)]-0.35Sr_(0.7)Bi_(0.2)TiO_(3)中引入MgO,并采用固相烧结法制备了不同摩尔含量(x=0.01~0.06)的0.65[(Na1-x,Mgx)0.5Bi_(0.5)TiO_(3)]-0.35Sr_(0.7)Bi_(0.2)TiO_(3)(NBT-SBT)陶瓷样品。通过SEM观察和XRD表征,发现随着Mg^(2+)含量的增加,NBT-SBT陶瓷的晶粒尺寸呈先减小后增大的变化,在Mg^(2+)掺入量(x)为0.025时,陶瓷晶粒尺寸最小。介电温谱和电滞回线测试表明该陶瓷为典型的铁电弛豫体,具有较高的介电常数(εr)和电极化强度(Pmax)。在100 k V/cm电场下,(Na0.94,Mg0.06)BT-SBT的可释放能量密度Wrec高达1.65 J/cm^(3),储能效率η为75%,综合性能优于同类NBT基陶瓷样品。结果表明,MgO掺杂的(Na1-x,Mgx)BT-SBT陶瓷具有优异的储能密度和效率,可为电子电力设备等领域的高功率储能电容器件的研究提供参考。
In this work,novel(1−x)(0.75Na_(0.5)Bi_(0.5)TiO_(3))-0.25Sr(Zr_(0.2)Sn_(0.2)Hf_(0.2)Ti_(0.2)Nb_(0.2))O_(3)-xNaNbO_(3)(NBT-SZSHTN-xNN,x=0.1,0.15,0.2,0.25)ceramics were fabricated.The influence of co-doping of NN and high entropy perovskite oxide(SZSHTN)on the phase structure,microstructure and dielectric properties of NBT-based lead-free ceramics was investigated.Dense microstructure with a grain size of~5μm is observed.When x=0.25,a wide dielectric temperature stable range of−35.4-224.3℃ with a low temperature coefficient of capacitance of<10%is achieved,fulfilling the industry standard of Y9P specification.Furthermore,excellent energy storage performance with recoverable energy density of 2.4 J/cm^(3),discharge efficiency of 71%,power density of 25.495 MW/cm^(3) and discharge rate<200 ns are simultaneously obtained,which shows great potential for high temperature capacitor applications.
Hongtian LiShiyu ZhouJianwei ZhaoTingnan YanYuxiao DuHuanfu ZhouYongping PuDawei Wang
