Achieving high energy storage density and charge-discharge performance via high-energy ball milling combined with two-step sintering

In this study, the microstructure, ferroelectricity, energy storage density, and charge-discharge characteristics of 0.95(K0.5Na0.5)NbO3-0.05Ba(Zn1/3Nb2/3) (0.95KNN-0.05BZN) ceramic, fabricated by combining two-step sintering with high-energy ball milling, were investigated. The two-step sintering technique enabled a wide sintering temperature range of 1020-1120 degrees C for the ceramic. Accordingly, under optimal sintering conditions, the ceramic exhibited high relative density (98.1 %) and nanoscale grain size (<90 nm). The samples also displayed excellent pulse power performance at room temperature with a high recoverable energy storage density (W-rec) of 3.1 J/cm(3), along with the following charge-discharge parameters: current density (C-D), power density (P-D), and discharge time (t(0.9)) reached 1821.7 cm(-3), 227.7 MW/cm(3), and 36.8 ns, respectively. The ceramic also obtained robust frequency stability (10-1000 Hz), good temperature stability (30-130 degrees C), and outstanding fatigue resistance (10(5) cycles), indicating its potential application in improved pulse capacitor materials.