ZHANG Deng ¹, YANG Song ¹, XU Yun ¹, LI Xiang ², WANG Xilin ², JIA Zhidong ², ZHOU Heping ²

(1. Dongguan Power Supply Bureau of Guangdong Power Grid Corporation, Dongguan 523000, Guangdong, China; 2. Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, Guangdong, China)

Abstract: Permittivity is one main factor that determines dielectric performance of insulative materials. The permittivity of epoxy resin usually ranges from 3 to 4. Mixing epoxy matrices with high-permittivity inorganic fillers is a common way to improve it. Yet there are few researches on constructing 3D structure with fillers before mixing. Achieved high-permittivity skeletons can better optimize the permittivity of insulative materials. 3D-structured BaTiO₃ ceramics were fabricated via ball-milling, freeze-drying, sintering procedures and examined via X-ray, SEM methods. The dielectric performance of ceramics/epoxy resin composites was tested via wideband dielectric spectrometer. With 30wt.% of the ceramics, the permittivity of composites reached 10.1 along with low loss tangent of 0.02. Applying the materials to a 2-layer insulator model led to an over 30% drop in local electric field near high-voltage electrode. The study provided a practical way of fabricating composites filled with nano-particles and also a solution to electric field relaxation around insulators.
Key words: nano-composites; 3D structure; dielectric performance; electric field optimization