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 (η). Whereas, W rec (<2 J/cm 3 ) and η (<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 P max and further obtain excellent energy storage properties in our study. (1– x )SrTiO 3 - x (0.93 Bi 0.5 Na 0.5 TiO 3 -0.07Ba 0.94 La 0.04 Zr 0.02 Ti 0.98 O 3 ) ((1– x )ST- x (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 ( P–E ) loops. The ceramic of 0.8ST-0.2(BNT-BLZT) possesses excellent energy storage properties with a W rec of 2.83 J/cm 3 and a η of 85% simultaneously. The significantly enhanced W rec (2.83 J/cm 3 ) is almost 2 times higher than the previous reported results of lead-free ceramics with η > 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.