Enhanced energy storage properties of Bi(Ni2/3Nb1/6Ta1/6)O3–NaNbO3 solid solution lead-free ceramics

Sodium niobate energy storage ceramics with good environmental performance are widely used in electric power conversion and pulse power system, large energy storage density and high efficiency, huge power density and charge and discharge faster. In this work, (1-x)NaNbO3-xBi(Ni2/3Nb1/6Ta1/6)O3 [(1-x)NN-xBNNT] (0.12 ≤ x ≤ 0.18) ceramics system were prepared by solid state reaction method. By introducing Bi(Ni2/3Nb1/6Ta1/6)O3 (BNNT), a relaxation strategy was constructed, which significantly improved the energy storage properties of NaNbO3 (NN) based ceramics. Finally, comparatively high recoverable energy density (Wrec) of 3.43 J/cm3 and large energy storage efficiency (η) of 83.3% were obtained in 0.86NN-0.14BNNT ceramics. Besides discharge energy density (Wd) of 0.69 J/cm3, ultra fast charge-discharge rate (t0.9) of 55 ns, the power density (PD) of 70.66 MW/cm3 and the current density (CD) of 883.23 A/cm2 were also observed in ceramic.