| Pulse forming line is a kind of important device which can compress the energy power.With the development of pulse power technology,the equipment miniaturization require smaller pulse forming.In order to meet the needs of miniaturization of solid pulse forming line,the key to solve this problem is preparation an energy storage ceramic that has high dielectric breakdown strength and high energy storage density.In this paper,the nanopowder with“core-shell”structure was prepared by chemical coating method.And the effect of silica coating of the sintered SrTiO3 ceramics on the microstructures and energy storage properties was investigated.We hope to find out a new kind of energy storage ceramic material that has high dielectric breakdown strength and high energy storage density.This paper studies the fabrication core-shell structure for SrTiO3 powder.Then we discusses the effect of core-shell structure powder on the electric properties of ceramics.We get such result below:?1?The core-shell nanopowder was synthesized via a core-shell nano-scale technique that is known as the St?ber process.The silica coating on SrTiO3 surface get core-shell structure powder and the thickness of shell can be efficiency controlled by add different content of TEOS with the PH and solution concentration is constant.?2?The effect of the SiO2 concentration on microstructure,dielectric response and energy storage properties of SrTiO3@SiO2 ceramics was investigated.The results show that both breakdown strength and energy density improved apparently.The composition for SrTiO3 coated with 3.0 wt%SiO2 shows the maximum breakdown strength of 340 kV/cm.The composition for SrTiO3 coated with 2.5 wt%SiO2 shows the maximum energy storage density?1.2 J/cm3?and a breakdown strength of 310kV/cm.After increasing SiO2,a secondary phase appeared due to inter-diffusion reactions between the core and silica shells during the sintering process.Measurements of the dielectric performance indicate that the SrTiO3@SiO2 ceramics possess good bias stabilities compared to pure ST ceramics.?3?The?Ba,Sr?TiO3@SiO2 core-shell nanopowder with different Ba/Sr ratio was synthesized via a nano-scale technique that is known as the St?ber process.The effect of the SiO2 concentration on microstructure,dielectric response and energy storage properties of?Ba,Sr?TiO3@SiO2 ceramics was investigated.The composition for Ba0.1Sr0.9TiO3 coated with 3 wt%SiO2 shows the high energy storage density?1.14J/cm3?.The composition for Ba0.3Sr0.7TiO3 coated with 3 wt%SiO2 shows the high energy storage density?1.5 J/cm3?and the breakdown strength of 370 kV/cm.The composition for Ba0.4Sr0.6TiO3 coated with 3 wt%SiO2 shows the high energy storage density?1.07 J/cm3?which shows the huge application prospects on Pulse forming line.After increasing SiO2,a secondary phase appeared due to the reactions between the core and silica shells.The results shows that breakdown strength improved apparently and the dielectric constant reduced.The silica shell inhibited the grain growth during the sintering process. |
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