Li Chongyang, Liu Jikang, Lin Long, Bai Wangfeng, Wu Shiting, Zheng Peng, Zhang Jingji, Zhai Jiwei
College of Materials and Environmental Engineering, Hangzhou Dianzi University, No. 2 Street, Hangzhou, 310018, China.
Key Laboratory of Novel Materials for Sensor of Zhejiang Province, Hangzhou Dianzi University, Hangzhou, 310012, China.
Small. 2023 Mar;19(12):e2206662. doi: 10.1002/smll.202206662. Epub 2023 Jan 1.
The development of high-performance lead-free dielectric ceramic capacitors is essential in the field of advanced electronics and electrical power systems. A huge challenge, however, is how to simultaneously realize large recoverable energy density (W ), ultrahigh efficiency (η), and satisfactory temperature stability to effectuate next-generation high/pulsed power capacitors applications. Here, a strategy of utilizing nanoscale polarization heterogeneous regions is demonstrated for high-performance dielectric capacitors, showing comprehensive properties of large W (≈6.39 J cm ) and ultrahigh η (≈94.4%) at 700 kV cm accompanied by excellent thermal endurance (20-160 °C), frequency stability (5-200 Hz), cycling reliability (1-105 cycles) at 500 kV cm , and superior charging-discharging performance (discharge rate t ≈ 28.4 ns, power density PD ≈161.3 MW cm ). The observations reveal that constructing the polarization heterogeneous regions in a linear dielectric to form novel relaxor ferroelectrics produces favorable microstructural characters, including extremely small polar nanoregions with high dynamics and multiphase coexistence and stable local structure symmetry, which enables large breakdown strength and ultralow polarization switching hysteresis, hence synergistically contributing to high-efficient capacitive energy storage. This study thus opens up a novel strategy to design lead-free dielectrics with comprehensive high-efficient energy storage performance for advanced pulsed power capacitors applications.
高性能无铅介电陶瓷电容器的开发在先进电子和电力系统领域至关重要。然而，一个巨大的挑战是如何同时实现大的可恢复能量密度（W）、超高效率（η）和令人满意的温度稳定性，以实现下一代高/脉冲功率电容器的应用。在此，展示了一种利用纳米级极化异质区域的策略用于高性能介电电容器，其在700 kV/cm下表现出大的W（≈6.39 J/cm³）和超高η（≈94.4%）的综合性能，同时在500 kV/cm下具有优异的热耐久性（20 - 160°C）、频率稳定性（5 - 200 Hz）、循环可靠性（1 - 10⁵次循环）以及卓越的充放电性能（放电速率t≈28.4 ns，功率密度PD≈161.3 MW/cm³）。观察结果表明，在线性电介质中构建极化异质区域以形成新型弛豫铁电体可产生有利的微观结构特征，包括具有高动力学的极小极性纳米区域、多相共存以及稳定的局部结构对称性，这使得能够实现高击穿强度和超低极化切换滞后，从而协同促进高效电容储能。因此，本研究为设计具有综合高效储能性能的无铅电介质以用于先进脉冲功率电容器应用开辟了一种新策略。
