Achieving ultrahigh energy storage density and efficiency in 0.90NaNbO ₃–0.10BaTiO ₃ ceramics via a composition modification strategy

Abstract

Ceramic capacitors feature great power density, fast charge/discharge rates, and excellent thermal stability.

Abstract

Ceramic capacitors feature great power density, fast charge/discharge rates, and excellent thermal stability. The poor energy storage density of ceramic capacitors, on the other hand, significantly limits their application in power systems. In this work, a high recoverable energy storage density of W _rec = 2.68 J cm ⁻³ and an ultrahigh efficiency of η = 90% are simultaneously achieved in the 0.90NaNbO ₃–0.10BaTiO ₃ ceramic by doping (Bi _0.7La _0.3)(Mg _0.67Ta _0.33)O ₃ (NNBT– xBLMT). Due to its high bandgap, the NNBT–0.10BLMT ceramic has a large dielectric breakdown strength (BDS) of 414 kV cm ⁻¹, consistent with the first-principles calculation based on density functional theory (DFT). Moreover, the NNBT–0.10BLMT ceramic exhibits excellent charge/discharge characteristics, with an ultrahigh current density C _D of 526.06 A cm ⁻² and a high power density P _D of 52.61 MW cm ⁻³. In particular, the NNBT–0.10BLMT ceramic exhibits an outstanding temperature (20 °C–110 °C), frequency (10 Hz–120 Hz), and cycling (10 ⁴ cycles) stability, highlighting its application potential in MLCCs.