BaTiO ₃ -based multilayer ceramic capacitors with superior stability in energy-storage and pulse properties

Dielectric capacitors exhibiting high energy-storage properties and excellent pulse performance are critical components in advanced pulsed power systems. The multilayer ceramic capacitors (MLCCs) are the most widely used capacitors, due to the high integration and excellent high-temperature endurance. Nevertheless, achieving high energy density and reliable performance at wide temperature range and prolonged cycling remains the major challenge for existing commercial MLCCs based on linear dielectrics or Pb-based antiferroelectrics. Herein, we developed BaTiO₃-based relaxor ferroelectric MLCCs with X9S characteristic for high-voltage applications. The BaTiO₃-based MLCCs exhibiting a good energy density of 6.09 J cm^-3 and an ultrahigh efficiency of 98.2%, with a superior stability in temperature (<10%, 24~250 ℃) and fatigue (after 10⁶ cycles, <4% at 200 ℃). The pulse properties of MLCCs show a minimal variation (<4.5%, 22~200 ℃). Moreover, 6878-size MLCCs with 300 nF can release a peak current of 3600 A at rated voltage of 3000 V, which exhibit higher peak currents than linear MLCCs and better stability than Pb-based MLCCs. The excellent performance and superior stability demonstrate that the relaxor ferroelectrics MLCCs have great potential for advanced energy-storage and pulsed power applications.