Novel nanostructure composite dielectric with high insulation performance: Silica-based nanometer-sized porous composite insulating paper reinforced by ceramic fibers

Nano-dielectrics, which were discovered more than 20 years ago, were once considered as promising insulators. Adding or hybridizing inorganic oxides into polymer matrices inevitably results in poor compatibility between multiphase materials and thus results in limited breakdown strength improvement (generally lower than 20%). Therefore, we bypassed the traditional nano-doping method and proposed the direct construction of matrix materials on nanostructures, that is, a ceramic fiber-porous silica composite insulating paper. The breakdown strength of prepared dielectric was remarkably improved by 120.5%. To the best of our knowledge, such a high improvement in electrical performance has not been reported in previous studies.