Achieving outstanding temperature and frequency stability in NaNbO3-modified (Ba0.94Li0.02La0.04)(Mg0.04Ti0.96)O3 pulse energy storage ceramics

Abstract

A novel binary pulse energy-storage ceramic of the (1−x)(Ba_0.94Li_0.02La_0.04)(Mg_0.04Ti_0.96)O_3−xNaNbO₃ system was designed and prepared utilizing the solid-state reaction route and filming technology. The conspicuous frequency stability, temperature stability, and anti-fatigue feature of the pulse energy-storage ceramics are all less than 10% at x = 0.15. The grain size, resistance of grain and grain boundary, bandgap width, and domain size of the ceramics are decreased by NaNbO₃. The finite element simulation manifests the small grain size and the high grain boundary density dominate the dielectric-breakdown process. A flattened dielectric peak appears at x = 0.1–0.2, and the improved temperature stability is induced by the orthorhombic phase of NaNbO₃. A satisfactory recoverable energy-storage density of 4.12 J cm⁻³, energy-storage efficiency of 82.1%, and discharge energy density of 3.21 J cm⁻³ are gained at x = 0.15 combined with excellent current density of 1572.98 A cm⁻² and power density of 314.59 MW cm⁻³. Piezoelectric force microscopy reveals that the decreased discharge energy density with temperature can be attributed to the migration of intrinsic charge carrier and the weakened interaction force between the cation and anion. The noticeable parameters indicate that the 0.85(Ba_0.94Li_0.02La_0.04)(Mg_0.04Ti_0.96)O₃–0.15NaNbO₃ ceramic is a promising potential candidate in the pulse electronics field. This study also provides a new strategy for designing pulse energy-storage ceramics with wide range temperature stability.