Novel Strontium Titanate-Based Lead-Free Ceramics for High-Energy Storage Applications

To achieve the miniaturization and integration of advanced pulsed power capacitors, it is highly desirable to develop lead-free ceramic materials with high recoverable energy density (W-rec) and high energy storage efficiency (eta). Whereas, Wrec (<2 J/cm(3)) and eta (<80%) have be seriously restricted because of low electric breakdown strength (BDS < 200 kV/cm) or small maximum polarization (P-max.). Composition control was used to enhance the Pm., and further obtain excellent energy storage properties in our study. (1-x)SrTiO3-x(0.93 Bi0.5Na0.5TiO3-0.07Ba(0.94)La(0.04)Zr(0.02)Ti(0.98)O(3)) ((1-x)STx(BNT-BLZT)) ternary solid solution ceramics with x = 0.0-0.5 were fabricated using the tape-casting process and sintered by solid-state sintering method. All the samples show slim polarization-electric field (PE) loops. The ceramic of 0.8ST-0.2(BNT-BLZT) possesses excellent energy storage properties with a Wmc of 2.83 J/cm(3) and a eta of 85% simultaneously. The significantly enhanced W, (2.83 J/cm(3)) is almost 2 times higher than the previous reported results of lead-free ceramics with eta > 80%. The results indicate that (1 x)ST-(x)(BNT-BLZT) lead-free ceramics can be used for pulsed power capacitors and open up a new research of ST-based ceramics.