钛酸锶钡储能陶瓷的低温烧结和介电性能研究

发布时间：2018-06-07 02:22

本文选题：钛酸锶钡 + 储能密度　；参考：《景德镇陶瓷学院》2015年硕士论文

【摘要】：钛酸锶钡BST)是BaTiO3和SrTiO3的无限固溶体,具有AB03型钙钛矿结构。随着Ba掺杂量x从0到1变化,BST陶瓷从立方顺电相的SrTiO3转变为四方铁电相的BaTiO3,其居里温度可以从接近绝对零度至120℃之间调节,从而具有不同的介电性能满足不同的应用要求。当0≤x≤0.4时,BST陶瓷的居里温度远低于室温,因此其在室温下为立方顺电相,可近似认为是线性电介质,是固态储能介质材料理想的候选体系之一。本文首先选取BaxSr1-xTiO3(BST,x≤0.4)陶瓷为对象,研究了不同x值对陶瓷相结构、微观结构、介电性能和储能特性的影响规律,重点优化了BST陶瓷在高电场作用下储能密度和能量效率之间的关系。结果表明：BST陶瓷在室温下均为纯的立方钙钛矿结构,陶瓷晶粒尺寸大小为几至十几微米,且微观结构致密；随着x值的增大,BST陶瓷的居里温度逐渐向高温方向移动,但均远低于室温;在给定的电场下,随着x值的增大,BST陶瓷的储能密度逐渐增加,而能量效率逐渐减小。室温下Bao.3Sro.7TiO3陶瓷具备较高介电常数(εr=650@1kHz)和非常低的介电损耗(tanδ=7.6×10-4@1kHz),当外加电场为90kV/cm时,Ba0.3Sr0.7TiO3陶瓷具有优化的储能密度(γ=0.23J/cm3)和能量效率(11=95.7%),更适合于固体脉冲功率储能应用。其次,选取BaxSr1-xTiO3(x=0.3,0.4)陶瓷为基体,采用BBS熔块对其进行降温烧结,研究了熔块添加量对陶瓷的相结构、微观结构、介电性能以及储能特性的影响规律。结果表明：BBS熔块的添加能够使陶瓷的烧结温度从1350℃降低至1150℃。与此同时,BBS熔块的添加使得陶瓷中出现杂相2CaO·SiO2和3CaO·SiO2,且细化了晶粒尺寸,提高了陶瓷致密度,改善了陶瓷的耐压强度。当所加电场为135kV/cm时,Ba0.3Sr0.7TiO3陶瓷储能密度为0.4724J/cm3,是纯Ba0.3Sr0.7TiO3陶瓷的1.17倍；当所加电场为110kV/cm时,Ba0.4Sr0.6TiO3陶瓷储能密度为0.3977J/cm3,是纯Ba0.4Sr0.6TiO3陶瓷的1.26倍。特别地,BBS熔块的添加能够显著降低陶瓷在高温条件下的介电损耗,当BBS熔块添加量为4wt%时,Ba0.3Sr0.7TiO3陶瓷在220℃时的介电损耗仍然小于0.05,而Ba0.4Sr0.6TiO3陶瓷介电损耗小于0.05的温度则达到250℃。因此,BBS熔块的掺杂拓展了BST储能陶瓷在高温领域的应用。最后,仍然选取BaxSr1-xTiO3(其中x=0.3,0.4)陶瓷为基体,进一步改进熔块的配方组成,在BBS熔块配方基础上添加了A1203和Zr02网络中间体,制成BBSZ熔块,研究了BBSZ熔块添加量对陶瓷的相结构、微观结构、介电性能以及储能特性的影响规律。结果表明：BBSZ熔块的添加同样在1150℃下实现了陶瓷的烧结,且陶瓷中出现第二相3CaO·SiO2,陶瓷的微观结构呈现大晶粒与小晶粒交错紧密结合特征。BBSZ熔块掺杂对提高陶瓷耐压强度较BBS熔块掺杂更为显著,这可能是熔块中引入网络中间体的缘故。当所加电场为160kV/cm时,Ba0.3Sr0.7TiO3陶瓷储能密度为0.6337J/cm3,是纯Ba0.3Sr0.7TiO3陶瓷的1.57倍,当所加电场为130kV/cm时,Ba0.4Sr0.6TiO3陶瓷储能密度为0.5044J/cm3,是纯Ba0.4Sr0.6TiO3陶瓷的1.59倍。BBSZ熔块同样能够显著降低陶瓷的高温介电损耗,当BBSZ熔块添加量为4wt%时,Ba0.4Sr0.6TiO3和Ba0.3Sr0.7TiO3陶瓷介电损耗小于0.05的温度分别能够达到260℃和300℃,显示了该陶瓷在高温储能应用领域的巨大潜在价值。
[Abstract]:Barium strontium titanate BST is an infinite solid solution of BaTiO3 and SrTiO3 with AB03 perovskite structure. As Ba doping x changes from 0 to 1, BST ceramics from cubic CIS phase SrTiO3 to tetragonal ferroelectric phase BaTiO3, and the Curie temperature can be transferred from near absolute zero to 120 C, thus different dielectric properties can be different. Application requirements. When 0 < < x > 0.4, the Curie temperature of BST ceramics is much lower than that of room temperature. Therefore, it is a cubic paraelectric phase at room temperature. It can be considered as a linear dielectric. It is one of the ideal candidate systems for solid state energy storage materials. This paper first selected BaxSr1-xTiO3 (BST, x < 0.4) ceramics as the object, and studied the structure of ceramic phase with different x values. The relationship between the microstructure, dielectric properties and energy storage characteristics, the relationship between the energy storage density and energy efficiency of BST ceramics under high electric field is optimized. The results show that BST ceramics are pure cubic perovskite structure at room temperature, the size of the ceramics is a few to ten microns, and the microstructure is compact, with the x value. The Curie temperature of BST ceramics moves towards high temperature, but it is far lower than room temperature. Under the given electric field, with the increase of x value, the energy storage density of BST ceramics increases gradually, while the energy efficiency decreases gradually. The Bao.3Sro.7TiO3 ceramics at room temperature have higher dielectric constant (E r=650@1kHz) and very low dielectric loss (tan delta =7.6 x 10-4@). 1kHz), when the applied electric field is 90kV/cm, the Ba0.3Sr0.7TiO3 ceramics have an optimized energy storage density (gamma =0.23J/cm3) and energy efficiency (11=95.7%), which is more suitable for the application of solid pulse power storage. Secondly, BaxSr1-xTiO3 (x=0.3,0.4) ceramics are selected as the matrix, and BBS melt blocks are used to reduce the temperature and sintering of the ceramics, and the phase junction of the fuses added to the ceramics is studied. The effect of microstructure, microstructure, dielectric properties and energy storage characteristics shows that the addition of BBS fusion can reduce the sintering temperature of the ceramic to 1150 degrees C from 1350 to 1150. Meanwhile, the addition of the BBS melting block makes the ceramics appear 2CaO / SiO2 and 3CaO. The grain size is refined, the density of ceramics is improved and the ceramics are improved. When the electric field is 135kV/cm, the energy density of the Ba0.3Sr0.7TiO3 ceramic is 0.4724J/cm3, which is 1.17 times that of the pure Ba0.3Sr0.7TiO3 ceramic. When the electric field is 110kV/cm, the density of the Ba0.4Sr0.6TiO3 ceramic energy is 0.3977J/cm3, which is 1.26 times that of the pure Ba0.4Sr0.6TiO3 ceramics. In particular, the addition of the BBS frit can significantly reduce the pottery. When the dielectric loss of porcelain is at high temperature, when the amount of BBS fusion is 4wt%, the dielectric loss of Ba0.3Sr0.7TiO3 ceramics at 220 C is still less than 0.05, while the dielectric loss of Ba0.4Sr0.6TiO3 ceramics is less than 0.05. Therefore, the doping of BBS frit expands the application of BST energy storage ceramics in the field of high temperature. Finally, Bax is selected as Bax. Sr1-xTiO3 (x=0.3,0.4) ceramic is the matrix to further improve the composition of the frit. On the basis of the BBS frit formula, a A1203 and Zr02 network intermediate is added to make a BBSZ fuse. The effect of the addition amount of the BBSZ frit on the phase structure, microstructure, dielectric properties and energy storage characteristics of the ceramics is studied. The results show that the BBSZ fuse is in the form of BBSZ frit. The addition of the ceramic in the same way at 1150 C, and the second phase 3CaO. SiO2 appears in the ceramics. The microstructure of the ceramics shows the interlacing characteristic of the large grain and the small grain. The doping of the.BBSZ frit is more significant than the BBS frit. This may be the cause of the introduction of the network intermediate in the melting pot. When the field is 160kV/cm, the energy density of Ba0.3Sr0.7TiO3 ceramics is 0.6337J/cm3, which is 1.57 times that of pure Ba0.3Sr0.7TiO3 ceramics. When the electric field is 130kV/cm, the density of Ba0.4Sr0.6TiO3 ceramic energy is 0.5044J/cm3, and the 1.59 times.BBSZ frit of pure Ba0.4Sr0.6TiO3 ceramics can also significantly reduce the dielectric loss of ceramics at high temperature, when BBSZ fusion is added. When the volume is 4wt%, the dielectric loss of Ba0.4Sr0.6TiO3 and Ba0.3Sr0.7TiO3 ceramics is less than 0.05, and the temperature can reach 260 C and 300 C, which shows the great potential value of the ceramic in the application field of high temperature energy storage.
【学位授予单位】：景德镇陶瓷学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ174.1

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