高储能密度玻璃陶瓷复合材料的充放电性能研究

发布时间：2018-01-06 04:27

本文关键词：高储能密度玻璃陶瓷复合材料的充放电性能研究　出处：《北京有色金属研究总院》2015年硕士论文　论文类型：学位论文

【摘要】：本文利用可控结晶技术,通过改变结晶工艺,制备了PbO-SrO-Na2O-Nb2O5-SiO2 (PSNNS)、PbO-BaO-Na2O-Nb2O5-SiO2 (PBNNS)和 BaO-SrO-Na2O-Nb2O5-SiO2 (BSNNS)三种体系玻璃陶瓷复合材料,分析了其结晶行为,研究了结晶条件改变对玻璃陶瓷介电性能、充放电性能的影响,结合微观分析与阻抗谱结果探讨了影响材料特性的原因。本文的主要内容如下：根据差热分析结果,确定PSNNS 、BSNNS及PBNNS玻璃陶瓷结晶温度为750℃与900℃,在此温度下将样品的结晶时间由1 min增加至1000 min,制备了一系列玻璃陶瓷样品。X射线衍射结果表明,结晶在很短时间内完成,900℃下析出相为NaNbO3高介电陶瓷相与相应体系的钨青铜陶瓷相,随着结晶时间的增加,析出相恒定,结晶峰强度基本不变。进一步的透射电镜结果表明,析出陶瓷相均匀弥散分布于玻璃基体中,随结晶时间增加,晶粒形貌基本不变,晶粒尺寸逐渐由几十纳米增加到几百纳米,最大不超过600 nm。采用LCR分析仪与铁电测试仪测试了玻璃陶瓷的介电性能。发现900℃结晶样品较750℃样品具有更高的介电常数,更强的极化特性；随着结晶时间增加,玻璃陶瓷样品的介电常数与介电损耗逐渐增大；极化曲线总体上十分纤细,极化强度与电场强度呈线性关系,随结晶时间的增加,剩余极化强度逐渐增大,玻璃陶瓷样品的铁电特性增强。采用极化曲线与脉冲放电回路两种测量方法分别研究了玻璃陶瓷在准静态放电与脉冲放电下的能量特性。在准静态放电条件下,PSNNS与PBNNS玻璃陶瓷均具有较高的能量密度,在10 kV/mm场强下分别达到0.172 J/cm3与0.197 J/cm3, PSNNS与BSNNS玻璃陶瓷具有更高的能量释放效率,分别高于85.0%与83.5%；随着结晶时间增加,玻璃陶瓷能量密度逐渐增加,能量释放效率逐渐降低。在脉冲放电条件下,随结晶时间增加,PSNNS玻璃陶瓷能量密度逐渐增加,能量释放效率显著降低；脉冲能量效率介于65.1-82.4%,明显低于相应PSNNS的准静态能量释放效率。电化学阻抗谱分析结果表明,随着结晶时间增加,极化弛豫时间增加；对于同一体系样品,晶相弛豫时间与界面弛豫时间差异巨大。这可能是造成充放电性能随结晶时间逐渐变化,且脉冲条件下能量释放效率大幅低于准静态条件下的原因。
[Abstract]:Using the controllable crystallization technology, by changing the crystallization process, to prepare PbO-SrO-Na2O-Nb2O5-SiO2 (PSNNS), PbO-BaO-Na2O-Nb2O5-SiO2 (PBNNS) and BaO-SrO-Na2O-Nb2O5-SiO2 (BSNNS) three system glass ceramic composite materials, analysis of the crystallization behavior, studied crystallization conditions change on the electrical properties of glass ceramics. The effect of charge discharge performance, combined with the microscopic analysis and impedance spectroscopy results discussed the influencing factors of material properties. The main contents of this paper are as follows: to determine the PSNNS according to the results of differential thermal analysis, BSNNS, and PBNNS glass ceramics crystallization temperature is 750 DEG and 900 DEG C, the temperature of crystallization time of samples increased from 1 min to 1000 min, the preparation of a series of glass ceramics sample.X X-ray diffraction shows that the crystal in a very short period of time, at a temperature of 900 DEG C to precipitate tungsten bronze ceramics NaNbO3 high dielectric ceramics and corresponding system with phase. Increase the crystallization time, constant precipitation, crystallization peak strength basically unchanged. TEM further results show that the precipitation of ceramic phase is uniformly dispersed in the glass matrix, with the crystallization time increases, the grain morphology is basically unchanged, the grain size gradually increased from tens of nanometers to hundreds of nanometers, the maximum not more than 600 dielectric properties of nm. glass ceramics was tested by LCR analyzer and ferroelectric tester. 900 C 750 C samples than crystalline samples has higher dielectric constant, the polarization characteristics of stronger; as the crystallization time increases, the glass ceramics, the dielectric constant and dielectric loss increased; polarization curve on the whole very slender, linear polarization with the electric field strength, with the increase of crystallization time, the remanent polarization increases gradually, enhance the ferroelectric properties of glass ceramic samples. Using polarization curve and pulse discharge circuit two Measurement techniques are used to study the energy characteristics of glass ceramics in quasi static discharge and pulse discharge. The discharge in the quasi-static conditions, PSNNS and PBNNS glass ceramics have high energy density, 10 kV/mm in the field were respectively 0.172 J/cm3 and 0.197 J/cm3, PSNNS and BSNNS glass ceramics have higher energy releasing efficiency. More than 85% and 83.5% respectively; as the crystallization time increases, the energy density of glass ceramics gradually increased, energy releasing efficiency decreased gradually. The pulse discharge conditions, with the increase of crystallization time, PSNNS glass ceramic energy density increases gradually, the energy release efficiency is significantly reduced; the pulse energy efficiency is 65.1-82.4%, significantly lower than the corresponding quasi-static energy releasing efficiency PSNNS the electrochemical impedance spectroscopy. The results showed that with the increase of crystallization time, polarization relaxation time increases; for the same sample system, phase relaxation The difference between the time of relaxation and the interfacial relaxation time is very large. This may be the gradual change of charge discharge performance with the crystallization time, and the energy release efficiency under pulse condition is much lower than that under quasi-static condition.

【学位授予单位】：北京有色金属研究总院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

【共引文献】