Ultrahigh energy density and efficiency BaTiO3-based multilayer ceramic capacitors

Abstract

Multilayer ceramic capacitors (MLCCs) play a crucial role in pulsed power applications because of their rapid charge/discharge capabilities. However, the combination of high energy density and high efficiency is the main challenge in practical applications. This study presents barium titanate-based (BaTiO3-) lead-free relaxor ferroelectric (RFE) MLCCs formulated with 0.84BaTiO3–0.16Bi(Mg0.2Ni0.2Zn0.2Zr0.2Nb0.2)O3 (0.84BT–0.16BMNZZN) and platinum inner electrodes via a tape-casting method. The introduction of the high-entropy component BMNZZN effectively enhances the relaxation behavior and local nanodomains while promoting grain refinement, resulting in a comprehensive improvement in insulation performance and energy storage performance. As a result, MLCCs exhibit excellent recoverable energy density (Wrec = 15.7 J∙cm−3) and ultrahigh efficiency (η) of 96.4% (@1614 kV∙cm−1), simultaneously showing good temperature stability over a range of −120‒100 °C (Wrec ≈ 8.9 J∙cm−3 with a variation of less than ±4.85%, @1078 kV∙cm−1) and excellent fatigue resistance (Wrec ≈ 9.2 J∙cm−3 with a variation of less than ±0.82% over 107 cycles, and η greater than 95%, @1078 kV∙cm−1). These findings indicate that BT–BMNZZN RFE MLCCs offer a viable solution for high-power energy storage capacitors (Figure Presented).