All original data used in figures and tables of the manuscript are available in the dataset, which includes the XRD, variable temperature dielectric, room temperature frequency spectrum and ferroelectric performance measurements.A sol-gel method is employed for preparing high quality lead-free glass-ceramic samples (1-x) BCZT-x BBS – incorporating Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ (BCZT) powder and Bi₂O₃-B₂O₃-SiO₂ (BBS) glass doped additives with different values of x (x = 0, 0.05, 0.1, 0.15). With the increase of BBS content, the polarization degree gradually decreases, but the breakdown electric field intensity first increases and then decreases, reaching the maximum value of 141 kV/cm when x =0.1. The energy storage density is calculated according to the electric field and polarization intensity. The maximum energy storage density reaches 0.3907 Jcm^-3 at electric field of 130 kV/cm as x value is 0.05.

These data are derived directly from the test instruments and equipment. These data can be processed directly or indirectly to obtain the data in transit. Data such as X-ray diffraction (XRD), dielectric constant, frequency spectrum, temperature spectrum, and ferroelectric can be processed directly to produce graphs. Energy storage density and energy storage efficiency need to be calculated by the following formula:W_discharge= Pr Pmax EdP  ; energy storage efficiency= W_discharge /W_charge×100%.