摘 要

脉冲功率装置目前正朝着小型化、高功率化发展，因此迫切需要提高储能介质材料的介电常数和储能密度。钛酸锶钙陶瓷作为典型的线性储能介质，具有较高的介电击穿强度、较低的介电损耗、良好的温度和偏压稳定性等优点，在电能储存应用领域极具发展潜力。但是这个体系具有两大缺点：一是实际击穿强度远低于理论击穿强度，二是高电场下储能效率显著降低，限制了该体系商业化的应用。界面极化被认为是影响击穿强度与储能效率的一个重要的非本征因素。本研究的设计思路就是通过引入晶间相的方式调控界面极化，以实现储能性能的剪裁。

本研究首先通过固相法合成CST陶瓷，通过比较不同预烧温度及烧结温度下样品的显微结构和电学性能，找出CST陶瓷的最佳合成工艺（预烧温度1200 ^oC，烧结温度1400 ^oC）。其次设计引入不同电学性能（高绝缘性和高导电性）的晶间相并比较其对储能性能的影响，探讨并验证界面极化对储能性能的影响机制。在CST陶瓷中引入高绝缘性的HfO₂晶间相时，结果表明适量高绝缘性的晶间相能有效改善陶瓷材料的储能性能，与此同时陶瓷晶粒与晶界电学性能的差异得到缩小，界面极化的程度被削弱，说明界面极化的存在对储能性能有不利影响。在CST陶瓷中引入ZnO晶间相时，结果却与预期相反，储能性能得到改善，与引入HfO₂晶间相的情况类似，本研究对该现象做出了可能的解释。

关键词：线性CST陶瓷；晶间相；储能性能；界面极化

Abstract

Nowadays, the pulsed power device is developing toward a mini-type and high power way, so it is urgent to improve the dielectric constant and energy-storage density of dielectric material. As a typical linear energy-storage material, the calcium strontium titanate ceramics possess advantages of higher dielectric breakdown strength, lower dielectric loss, favorable temperature and bias voltage stability, as well as with great development potential in energy storage application field. But this system owns two weaknesses: the first one is the actual breakdown strength is much lower than theoretical breakdown strength, the second one is the energy-storage efficiency decreases markedly under high electric field, which limits the commercial application of this system. The interfacial polarization is regarded as an important extrinsic factor which affects breakdown strength and energy-storage efficiency. The design thought of this research focuses on adjusting and controlling interfacial polarization through introducing intergranular phases, to realize the tailoring of energy storage property.

Firstly, the research adopts traditional solid-state method to synthesize CST ceramic, through the comparison of samples' microstructure and electrical properties under different presintering temperature and sintering temperature, to find out the optimum synthetic process of CST ceramic (with 1200 ^oC presintering temperature, and 1400 ^oC sintering temperature). Then introduces intergranular phases of different electrical properties (high insulativity and high conductivity) and compares the effect of them on energy storage property, discusses and verifies the influencing mechanism of interfacial polarization on energy storage property. Introduce high insulation HfO₂ intergranular phase into CST ceramic, to research its influence on CST ceramic's energy storage property. The results show that moderate high insulation intergranular phases will improve the energy storage property of ceramic material effectively. The difference between ceramic grain and grain boundary electrical properties is reduced, and the degree of interfacial polarization is weaken, which indicates that the existence of interfacial polarization has negative influence for energy storage property. The result of introducing ZnO intergranular phase into CST ceramic is similar with introducing HfO₂ intergranular phase, which may be related to the special electrical property of ZnO. Under medium temperature sintering conditions, the introduced ZnO still possesses high insulativity rather than high conductivity as expected.

Keywords: linear CST ceramics, intergranular phases, energy storage performance, interfacial polarization

目 录

第1章 绪论 1

1.1脉冲功率技术中储能介质材料的发展概况 1

1.1.1 脉冲功率技术 1

1.1.2 储能介质材料 1

1.2线性储能介质材料的优势与发展情况 4

1.2.1 线性储能介质体系的优势 4

1.2.2 线性储能介质体系的发展情况 5

1.3本论文的研究目的与研究内容 6

1.3.1 研究目的 6

1.3.2 研究内容 6

第2章 氧化物添加介质陶瓷的制备工艺与测试方法 7

2.1氧化物添加Ca_0.6Sr_0.4TiO₃陶瓷的制备工艺 7

2.2实验药品及仪器设备 8

2.3介质陶瓷的结构表征及电学性能测试 9

2.3.1 密度测试 9

2.3.2 X射线衍射分析 9

2.3.3 显微结构分析 9

2.3.4 电学性能测试 10

第3章 烧结温度制度对CST陶瓷结构和电学性能的影响 12

3.1不同烧结温度制度对陶瓷样品宏观形貌的影响 12

3.1.1 预烧温度对样品线收缩率的影响 12

3.1.2 预烧温度对样品体积密度的影响 13

3.2不同烧结温度制度对陶瓷样品显微结构的影响 14

3.3预烧温度对样品电学性能的影响 18

3.4本章小结 20

第4章 HfO₂添加Ca_0.6Sr_0.4TiO₃陶瓷结构和储能性能的研究 22

4.1 Ca_0.6Sr_0.4TiO₃ x wt%HfO₂陶瓷的物相分析 22

4.2 Ca_0.6Sr_0.4TiO₃ x wt%HfO₂陶瓷的显微结构分析 24

4.3 Ca_0.6Sr_0.4TiO₃ x wt%HfO₂陶瓷的储能性能分析 25

4.4 Ca_0.6Sr_0.4TiO₃ x wt%HfO₂陶瓷储能性能与界面极化关系的研究 29

4.5 本章小结 30

第5章 ZnO添加Ca_0.6Sr_0.4TiO₃陶瓷结构和储能性能的研究 32

5.1 Ca_0.6Sr_0.4TiO₃ x mol%ZnO陶瓷的物相结构分析 32

5.1.1 X射线衍射分析 32

5.1.2 Ca_0.6Sr_0.4TiO₃ x mol%ZnO陶瓷的显微结构分析 33

5.2 Ca_0.6Sr_0.4TiO₃ x mol%ZnO陶瓷储能性能的分析 34

5.3 Ca_0.6Sr_0.4TiO₃ x mol%ZnO陶瓷储能性能与界面极化关系的研究 34

5.4 本章小结 35

第6章 结论 37

参考文献 38

致 谢 41

第1章 绪论

1.1脉冲功率技术中储能介质材料的发展概况

1.1.1 脉冲功率技术

脉冲功率科学技术，是以电气科学技术为基础，将电工新技术和高电压-大电流技术融为一体的一门新型学科^[1]。它的基本原理是将几百千到几十兆焦耳的小功率能量长时间地缓慢地输入到电容器、电感器等储能元件中，将能量进行压缩和转换，通过快速开关使能量在极短的时间内（例如微秒或纳秒时间内），通过脉冲功率发生装置有效地释放至负载，这样能够获得极高的功率（兆瓦量级）^[2]。