Effect of ZnS size on the dielectric and energy storage properties of ZnS/polymer composites

Dielectric polymer composites capable of withstanding a high electric field are highly desired in electronic devices and electric power systems, to ensure reliability and provide high energy density. In this work, ZnS particles with three sizes (100 nm, 500 nm and 3um) were prepared by using polyvinyl pyrrolidone (PVP) and cetyltrimethyl ammonium bromide (CATB) as capping agent. The ZnS filled PVDF films were obtained by a solution mixing and coating process. The dielectric properties and energy storage performance were investigated in detail. The films filled with 100nm-ZnS showed much higher breakdown strength, than the 500nm-ZnS and 3um-ZnS filled ones. When the loading of ZnS (100 nm) is 3 wt %, the film achieved enhanced energy storage properties (E_b~496.6 kV/mm, energy density~6.47 J/cm³).