Lead-free ferroelectric ceramics are very suitable for electrostatic energy storage capacitors due to their outstanding characteristics of high charge-discharge speed, high power density, and environmental friendliness. Herein, a novel material system as (1−x)Na 0.5 Bi 0.5 TiO 3-xCaZr 0.5 Ti 0.5 O 3 (NBT-CZT, x = 0, 0.05, 0.10, 0.12, 0.15, and 0.20) was designed and prepared for dielectric energy storage ceramics. It demonstrated that the CZT additives induced a phase transition for the NBT ceramics, from ferroelectric to relaxor ferroelectric. In particular, extremely high stored energy storage density (6.92 and 5.37 J/cm 3), high recoverable energy storage density (4.77 and 4.37 J/cm 3), and moderate efficiency (69.0% and 81.4%) were achieved in both the samples of x = 0.12 and x = 0.15, respectively. The ceramics exhibited excellent stability of energy storage performance covering a wide temperature (25°C-200°C) and frequency (0.5-50 Hz) range, and also fatigue cycles up to 10 5. Additionally, the NBT-CZT ceramics had a fast discharge speed (t 0.9 < 100 ns) and high power density (24.2 MW/cm 3 , E = 100 kV/cm, x = 0.15), and the charge-discharge process remained stable even when the measured temperature was up to 160°C. Therefore, the NBT-CZT ceramics have the potential to be utilized in electrostatic energy storage applications. K E Y W O R D S dielectric materials/properties, energy storage, ferroelectricity/ferroelectric materials, lead-free ceramics, titanates How to cite this article: Bian S, Yue Z, Shi Y, Zhang J, Feng W. Ultrahigh energy storage density and charge-discharge performance in novel sodium bismuth titanate-based ceramics.