Superior energy storage performance in NaNbO3‐based lead‐free ceramics under low electric field

Abstract NaNbO 3 (NN)‐based materials have attracted widespread attention due to their advanced energy storage performance and eco‐friendliness. However, achieving high recoverable energy storage densities ( W rec ) and efficiency ( η ) typically requires ultrahigh electric fields ( E > 300 kV/cm), which can limit practical use. In this work, we present a synergistic strategy that employs the ferroelectric material Bi 0.5 Na 0.5 TiO 3 (BNT) to augment the P max and the linear material Bi 0.2 Sr 0.7 TiO 3 (BST) to optimize the P – E loops. Furthermore, a two‐step sintering process is implemented to preserve high P max values under lower electric field. As a result, ternary (1− x )(0.90NN‐0.10BNT)‐ x BST was successfully prepared, achieving a high W rec of 5.1 J/cm 3 and a η of 85% in x = 0.20 samples at a low electric field of 290 kV/cm. Moreover, the x = 0.20 samples showed good frequency stability (1–200 Hz) and temperature stability (27°C–100°C). These results provide guidance for the development of ceramics with high energy storage properties under low electric fields.