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

NaNbO3-based (NN) energy storage ceramics are known for exhibiting high maximum polarization (P-max) and large recoverable energy density (W-rec). However, the huge energy loss density (W-loss) has been a limiting factor in improving energy storage performance. Therefore, a ternary system was designed to achieve both huge W-rec and efficiency (eta). The combination of 0.35Bi(Zn0.5Ti0.5)O-3-0.65BaTiO(3) (BZTBT) was chosen to reduce grain size and disrupt the long-range ordered domains, thereby inducing the polar-nano-regions to mitigate W-loss. The optimal performance was achieved with the 0.75NaNbO(3)-0.25(0.35Bi(Zn0.5Ti0.5)O-3-0.65BaTiO(3)) (0.75NN-0.25BZTBT) ceramic, which exhibited a high W-rec = 2.68 J/cm(3) and superior eta = 82.7% under 310 kV/cm. Remarkably, the 0.75NN-0.25BZTBT ceramic displayed an exceptionally fast discharge time to 90%, t(0.9) = 88 ns, coupled with a huge energy density W-d = 0.95 J/cm(3). This study demonstrates the significant potential of 0.75NN-0.25BZTBT ceramic in the realm of energy storage and rapid charge-discharge applications.