High-temperature lead-free dielectric ceramic capacitors are urgently needed in modern advanced power electronics systems. However, it is still a great challenge to realize both ultrahigh energy density (W_rec) and efficiency (η) under the harsh environment. In this work, the innovative 0.9(Sr_0.7Bi_0.2)TiO₃-0.1Bi(Mg_0.5Zr_0.5)O₃ (SBT-BMZ)-modified BaTiO₃ (BT) relaxor ferroelectric ceramics are ingeniously designed and synthesized via a solid-state reaction route. Optimal energy storage performances are attained in 0.65BT-0.35(SBT-BMZ) ceramic with an excellent W_rec of 4.03 J/cm³, couple with an ultrahigh η of 96.2% at 370 kV/cm, which are superior to other lead-free BT-based ceramics. The energy storage performances of the 0.65BT-0.35(SBT-BMZ) ceramic also display superior thermal stability (20 ∼ 180 °C) with a subtle change of W_rec (± 8%) and η (± 1%), frequency stability (1 ∼ 500 Hz) and cycle stability (1 ∼ 10⁶ cycles) at 200 kV/cm. Moreover, the charge and discharge experiments indicate that the outstanding power density (P_D ∼ 62.6 MW/cm³) and ultrafast discharge time (t_0.9 ∼ 62 ns) are also achieved. All these features demonstrate that the 0.65BT-0.35(SBT-BMZ) ceramic is expected to be widely used in next-generation of wide-temperature dielectric capacitors.

现代先进的电力电子系统迫切需要高温无铅介电陶瓷电容器。然而，在恶劣环境下实现超高能量密度（W _rec）和效率（η）仍然是巨大的挑战。在这项工作中，创新的0.9（Sr _0.7 Bi _0.2）TiO ₃ -0.1Bi（Mg _0.5 Zr _0.5）O ₃（SBT-BMZ）改性的BaTiO ₃（BT）弛豫铁电陶瓷是通过精心设计和合成的。状态反应路线。在0.65BT-0.35（SBT-BMZ）陶瓷中实现了最佳的储能性能，出色的W _rec为4.03 J / cm ³，在370 kV / cm时具有96.2％的超高η，优于其他无铅BT基陶瓷。0.65BT-0.35（SBT-BMZ）陶瓷的储能性能也显示出卓越的热稳定性（20〜180°C），W _rec（±8％）和η（±1％）的细微变化以及频率稳定性（1〜500 Hz）和200 kV / cm的周期稳定性（1〜10 ⁶个周期）。此外，充电和放电实验结果表明，优秀的功率密度（P _d〜62.6兆瓦/厘米³）和超快放电时间（t _0.9〜62纳秒），也能够实现。所有这些特征表明，0.65BT-0.35（SBT-BMZ）陶瓷有望被广泛用于下一代宽温度介电电容器中。