The study of rheology, dielectric, ferroelectric, energy storage properties of Mg-doped Na0.425Bi0.425Ca0.15TiO3 lead-free ceramics through a viscous polymer process

Lead-free relaxor ferroelectric ceramics 0.95Na0.425Bi0.425Ca0.15TiO3-0.05 Mg with different polyvinyl alcohol contents (NBCT-Mg-xPVA) were prepared by viscous polymer processing to generate high density and induce high breakdown strength (BDS) and high recoverable energy storage density (Wrec). The rheology properties of the ceramic pastes had been systematically studied. The content of PVA has exhibited a great influence on the microstructure and property of ceramics. Through the analysis of ceramics with different PVA contents, it is found that the less PVA content, the less pores and greater BDS on the premise of film formation. The related other electrical performances of the resulting ceramics have also been performed. Especially for the NBCT-Mg0.4PVA ceramics, the BDS of it reached as high as 320 kV/cm, and the Wrec was 4.51 J/cm3, which also exhibited excellent temperature stability (30-135 degrees C) and frequency stability (0.2-50 Hz), as well as good stability during charged-discharged process and achieve high power density.