Achieving outstanding temperature stability in KNN-based lead-free ceramics for energy storage behavior

Abstract

Lead-free ceramics with prominent energy storage properties are identified as the most potential materials accessed in the dielectric capacitors. Nevertheless, high recoverable energy storage density (Wrec), large energy storage efficiency (η) and preferable temperature stability can hardly be met simultaneously. The Bi(Zn2/3Ta1/3)O3 and NaNbO3 components are doped in KNN ceramics to substantiate the reliability of this tactic. A high recoverable energy density (Wrec) of ∼ 4.55 J/cm3 and a large energy storage efficiency (η) of ∼ 87.8% are acquired under the dielectric breakdown strength (DBS) of ∼ 375 kV/cm, along with a splendid thermal stability (Wrec variation: ∼ 2.3%, η variation: ∼ 4.9%) within the temperature range of 20 ℃− 120 ℃. This article demonstrates that the KNN-based ceramics integrate high energy storage properties and outstanding temperature stability at the same time, which broadens the application fields of pulse power systems.