Pulse discharge characterization of perovskite dielectric ceramics

The pulse discharge characterization of perovskite dielectric ceramics, which has confronted a barrier between research and application, has the problems of inconsistent test standards and lack of comparability. To mitigate this issue and further advance the application process, we suggest an extrinsic standard (for convenience of comparison) for energy dielectric ceramics of thickness (0.2 mm), electrode area (4 mm 2 ) and operation voltage (2 kV). We report the pulse discharge performance parameters of three typical dielectric materials: relaxor ferroelectric (Na 0.5 Bi 0.5 ) 0.9 Li 0.1 Ti 0.9 Ta 0.1 O 3 (NBLTT), paraelectric Ca 0.6 Sr 0.4 TiO 3 (CST) and linear dielectric K 0.5 Na 0.5 NbO 3 (KNN) glass ceramics through computer simulation and fitting of pulse discharge curves based on the resistance-inductance-capacitor pulse discharge circuit. The NBLTT ceramics exhibited higher peak current (16 A under 100 kV/cm) and stability with minimal variation less than 15% from 20 to 150 °C during pulse discharge compared with linear dielectric and ferroelectric glass ceramics. In addition, the NBLTT system holds the fast discharge time (90% of the discharge energy density released in about 100 ns) and good fatigue resistance. The short discharge time, high thermal stability and low medium voltage (500–5000 V) make the NBLTT ceramics promising for pulse capacitor in large current and low electric operation voltage conditions. An operable comparison standard and the research frontiers of pulsed dielectric materials are prospected.