Nonlinear electrical characteristics of core-satellite CaCu3Ti4O12@ZnO doped silicone rubber composites

The application of polymer composites with electric field dependent nonlinear conductive and dielectric characteristics for high voltage equipment is an effective method to control electric field stress and disperse space charges. In this study, core-satellite CaCu3Ti4O12@ZnO fillers were synthesized and doped into silicone rubber composites, and compared to a mixture of CaCu3Ti4O12 and ZnO with the same filler concentration. The composites exhibited both nonlinear conductive and nonlinear dielectric properties with nanoparticle fillers for the first time. Both the nonlinear conductive coefficient and dielectric coefficient increased with filler concentration. The classical current-path model was utilized to explain the nonlinear conductive properties, while the interface-barrier-layer-capacitor model and double-depletion-layer model were introduced to explain the nonlinear dielectric properties, which would broaden the thinking for the fabrication of nonlinear composites.