Achieving excellent energy storage performance with thermal stability in lead-free AgNbO₃ ceramics

Large hysteresis and low energy density of pure AgNbO₃ ceramics limit their further application in pulsed power techniques. Here, less-harmful Sm₂O₃-modified AgNbO₃ antiferroelectric ceramics were synthesized by a rolling process, in order to improve the energy storage performance. All the Sm₂O₃-doped samples display reduced hysteresis due to disrupted long-range order, as certified by Raman spectra. As expected, due to the large dielectric breakdown strength and reduced hysteresis, an improved energy storage density, W_rec, of 5.85 J cm^-3 and satisfactory energy efficiency, η, of 77% can be simultaneously achieved in the studied antiferroelectric ceramics, showing great superiority over other bulk electronic ceramics. Along with excellent temperature stability within the range of 20-150 °C at 320 kV cm^-1 (W_rec > 4.3 J cm^-3, with minimal variation of ≤4%) in the studied samples, this shows that AgNbO₃-based environmentally friendly ceramics are promising materials for pulsed power techniques.