Ultrafast discharge properties and enhanced energy density in lead‐free NaNbO₃‐based relaxor ferroelectric ceramics

Abstract

NaNbO3‐based (NN) energy storage ceramics are known for exhibiting high maximum polarization (Pmax) and large recoverable energy density (Wrec). However, the huge energy loss density (Wloss) has been a limiting factor in improving energy storage performance. Therefore, a ternary system was designed to achieve both huge Wrec and efficiency (η). The combination of 0.35Bi(Zn0.5Ti0.5)O3–0.65BaTiO3 (BZTBT) was chosen to reduce grain size and disrupt the long‐range ordered domains, thereby inducing the polar‐nano‐regions to mitigate Wloss. The optimal performance was achieved with the 0.75NaNbO3–0.25(0.35Bi(Zn0.5Ti0.5)O3–0.65BaTiO3) (0.75NN–0.25BZTBT) ceramic, which exhibited a high Wrec = 2.68 J/cm3 and superior η = 82.7% under 310 kV/cm. Remarkably, the 0.75NN–0.25BZTBT ceramic displayed an exceptionally fast discharge time to 90%, t0.9 = 88 ns, coupled with a huge energy density Wd = 0.95 J/cm3. This study demonstrates the significant potential of 0.75NN–0.25BZTBT ceramic in the realm of energy storage and rapid charge–discharge applications.