Enhanced pyroelectric properties of lead-free BNT-BA-KNN ceramics for thermal energy harvesting
Enhanced pyroelectric properties of lead-free BNT-BA-KNN ceramics for thermal energy harvesting
复制标题
用于热能收集的无铅 BNT-BA-KNN 陶瓷的增强热释电性能
DOI：
10.1111/jace.16250
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发表时间：
2019
影响因子：
3.9
通讯作者：
Jiang Shenlin
中科院分区：
文献类型：
--
作者：
Shen Meng;Qin Yanfeng;Zhang Yujing;Marwat Mohsin Ali;Zhang Chao;Wang Wanqiang;Li Mingyu;Zhang Haibo;Zhang Guangzu;Jiang Shenlin
本工作采用固相反应法制备了（1−x）（0.98Bi0.5Na0.5TiO3 - 0.02BiAlO3）-x（Na0.5K0.5）NbO 3（BNT-BA-xKNN）无铅热释电陶瓷。系统研究了Na0.5K0.5NbO3（KNN）含量对BNT-BA-xKNN陶瓷的显微结构、相变和电学性能的影响。结果表明，适量的KNN可以诱导四方结构的形成，从而使BNT晶格的长程平移对称性被破坏，导致铁电-反铁电相变温度降低.因此，BNT-BA-xKNN在室温附近的铁电和热释电性能得到改善。室温热释电系数从x =0时的3.66 × 10−4C/m2/K显著增加到x =0.02时的8.04 × 10−4C/m2/K，为上级热释电能量收集做出了巨大贡献。BNT‐BA‐0.02KNN的一个循环的输出能量密度为23.32 μJ/cm 3，这是原始样品的两倍。材料性能的提高表明，热释电能量收集可以有效地优化相结构的适当控制。
In this work, (1−x)(0.98Bi0.5Na0.5TiO3‐0.02BiAlO3)‐x(Na0.5K0.5)NbO3(BNT‐BA‐xKNN) lead‐free pyroelectric ceramics were prepared by a solid‐state reaction method. The effect of Na0.5K0.5NbO3(KNN) content on microstructure, phase transition, and electrical properties of the BNT‐BA‐xKNN ceramics were systematically investigated. The results show that the appropriate content of KNN can induce the formation of the tetragonal structure, which results in the decreased ferroelectric‐antiferroelectric phase transition temperature as a result of the break of long‐range translational symmetry of BNT lattices. Therefore, the ferroelectric and pyroelectric properties of the BNT‐BA‐xKNN near room temperature are improved. The room‐temperature pyroelectric coefficient significantly increases from 3.66 × 10−4C/m2/K atx=0 to 8.04 × 10−4C/m2/K atx=0.02, making a great contribution to the superior pyroelectric energy harvesting. The output energy density in one cycle of the BNT‐BA‐0.02KNN is 23.32 μJ/cm3, which is twice as high as that of the pristine samples. The enhancement of material properties suggests that the pyroelectric energy harvesting can be efficiently optimized by the adequate control of the phase structure.