Zhen Liu, Haonan Peng, Teng Lü, Tiantian Wu, Cheng Yang, Zhengqian Fu, Zhichao Hong, Jiyang Xie, T. Honda, Yonghong Chen, Wanbiao Hu, Fangfang Xu, Zhisheng Lin, Yun Liu, Shujun Zhang, Genshui Wang, Junhao Chu
High energy density lead-free dielectric capacitors play a pivotal role in state-of-the-art electrical and electronic systems. Nevertheless, the low energy storage capacities have persistently posed a significant impediment to the ongoing trend toward the miniaturization and integration of electronic devices. Here, we report an equimolar high-entropy relaxor ferroelectric multilayer capacitor that demonstrates exceptional energy storage performance by harnessing flexible multisite tetragonal tungsten bronze (TTB) high-entropy architecture. Our findings reveal that the equimolar high-entropy design results in NbO 6 octahedra distortion, disrupting long-range ferroelectric order while preserving strong off-center displacements along the polar axis at a local scale. This unique structure characteristic of high-entropy TTB not only enhances its relaxor feature, reducing hysteresis, but also maintains high polarizability under applied electric fields. Consequently, our high-entropy TTB multilayer ceramic capacitors achieved an unprecedented recoverable energy density of 20.2 J·cm –3, accompanied by a notably enhanced efficiency of 93.8%. This approach opens the door for the development of innovative functional ceramics and devices with prominent energy storage capability by designing flexible multisite high-entropy architecture.