The enhancement of energy storage performance of BaTiO3–Bi(Mg0·5Ti0.5)O3 Pb-free ceramics via an optimized viscous polymer process route

In this study, the viscous polymer processing (VPP) technique is implemented to optimize the characteristics of bulk (1- x )BaTiO 3 - x Bi(Mg 0·5 Ti 0.5 )O 3 (BT- x BMT) lead-free relaxor ferroelectric ceramics , with a focus on enhancing the recoverable energy storage density ( W rec ), improving breakdown strength resistance ( E b ), and increasing storage efficiency ( η ). The influence of polyvinyl alcohol (PVA) inclusion in the VPP process on the resulting dielectric ceramics is thoroughly investigated, covering rheological, dielectric, and ferroelectric properties . The results reveal that a gradual increase in PVA quantity during the VPP process effectively improves the density of ceramic blanks. However, an excess of PVA leads to void formation in the ceramic blanks post-debinding, hindering the achievement of a dense structure in the final ceramics and causing performance degradation. The resulting BT-0.405BMT-40 wt% PVA ceramic showed excellent storage performance, with W rec , η , and E b of 6.55 J/cm 3 81.45 %, and 480 kV/cm, respectively. In comparison to bulk BT-0.405BMT ceramics, there is a notable 2.47-fold increase in W rec and a 1.92-fold increase in E b , accompanied by a substantial improvement in η . Moreover, the BT-BMT-40 wt% PVA ceramic exhibits favorable temperature stability (30–150 °C), frequency stability (1–50 Hz), and commendable charge/discharge performance.