Simultaneously achieving high energy storage performance and low electrostrictive strain in BT-based ceramics

Dielectric ceramics with high recoverable energy storage density (W_rec) and high energy storage efficiency (η) are urgently needed due to their potential application in pulse capacitor devices. However, the low η and breakdown strength (BDS) have produced a bottleneck for achieving high W_rec at high electric field. Here, we introduce Bi(Mg_0.5Ti_0.5)O₃ (BMT) into Ba(Ti_0.92Sn_0.08)O₃ (BTS) matrix to enhance the relaxor character of BTS–xBMT and reduce the electrostrictive strain generated during electric field loading. The enhanced relaxor character is beneficial for increasing the efficiency, whereas the reduced electrostrictive strain is profitable to increase the BDS. Furthermore, the BDS is significantly improved by the polymer viscous rolling process. Finally, the electrostrictive effect was considerably lowered in an optimized BTS–0.1BMT composition. More crucially, a high W_rec of 4.34 J/cm³ was attained accompanied by excellent temperature stability (variation ≤±5% between 30 and 120°C). The current results show that the developed dielectric ceramics can be used in pulse capacitor devices for energy storage.