Significant improvement in energy storage for BT ceramics via NBT composition regulation

Dielectric ceramic capacitors play an important part in modern electronics, but the adoption of environmentally friendly lead-free ceramics is often limited by their inferior energy storage efficiency (η) and density (Wrec). One novel ceramic composition, (1-x)(Ba0.7Sr0.3)(Zr0.2Ti0.8)O3-xNa0.5Bi0.5TiO3 (BSZT-NBT, x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) was designed to achieve large max polarization (Pmax) and outstanding energy storage performance (ESP). Structural analyses indicate that BSZT-NBT ceramics form stable perovskite solid solutions. Dielectric properties testing confirms the enhanced relaxor behavior. Remarkably, the BSZT-NBT (x = 0.5) ceramics exhibit superb ESP, including ultrahigh η of 94.9%, elevated Wrec of 4.45 J·cm–3, large Pmax of 38.01 μC·cm–2. Furthermore, these ceramics demonstrate excellent temperature and frequency stability for ESP. Charge-discharge performance at room temperature and 120 kV·cm–1 showcases excellent Wdis, t0.9 and PD of 0.64 J·cm–3, 69.8 ns and 48 MW·cm–3, respectively. Our results indicate that the introduction of NBT effectively improves the Pmax and ESP of BT-based ceramics. The BSZT-NBT ceramics hold promise for addressing the limitations of lead-free ceramic capacitors and advancing their practical applications in electronic devices.