Ultrahigh energy efficiency of (1-x)Ba<inf>0.85</inf>Ca<inf>0.15</inf>Zr<inf>0.1</inf>Ti<inf>0.9</inf>O<inf>3</inf>-xBi(Mg<inf>0.5</inf>Sn<inf>0.5</inf>)O<inf>3</inf> lead-free ceramics

Abstract

Relaxor ferroelectrics (RFEs) with superior energy storage properties are the commonly selected materials for energy storage capacitors. In this work, a relaxor end-member of Bi(Mg0.5Sn0.5)O3 (BMS) was introduced into ferroelectric (FE) Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) ceramics, which remarkably inhibited grain growth and triggered a FE-to-RFE phase transition, as well as improved breakdown strength. An ultrahigh energy efficiency (η) of 97.6% with a high recoverable energy density (Wrec) of 1.703 J/cm3, and excellent temperature stability (30–130 °C) have been achieved in (1-x)Ba0.85Ca0.15Zr0.1Ti0.9O3-xBi(Mg0.5Sn0.5)O3 with x = 0.08 (BCZT-BMS8) ceramic, which is mainly due to the slim P-E loop and enhanced breakdown strength. It should be noted that the ultrahigh η of 97.6% for BCZT-BMS8 is quite attractive for further applications. Electron paramagnetic resonance signal of oxygen vacancies (g ~ 1.955) was detected in BCZT-based ceramics for the first time, which could be helpful to explore novel lead-free ceramics for energy storage capacitors.