Synergistic strategy of composition design and multiscale structure regulation for high energy storage performance of PLZT under low electric fields

Abstract

Dielectric energy storage ceramics have become the core driving force for the development of high-tech fields. However, the high energy storage density usually requires high electric field excitation; this not only increases the energy consumption of electric power resources but also raises the risk of device failure. Furthermore, it is often difficult to achieve a balance between recoverable energy density (W_rec) and efficiency (η). Therefore, developing high energy storage performance materials under low electric fields is a bottleneck issue. In this study, relaxor antiferroelectric ceramics of Pb_0.9325-xLa_0.045Ca_xZr_0.92Ti_0.075Hf_0.005O₃ (PLC_xZTH) were designed by a synergistic optimization strategy of composition design and multi-scale structure manipulation. Then, a high W_rec (∼5.15 J cm⁻³) and η (∼85.1%) under 230 kV cm⁻¹ were realized in PLC_0.03ZTH. Even when the working electric field was reduced to 190 kV cm⁻¹, the W_rec could still reach 4.05 J cm⁻³ with high η of 87.1%. The energy storage performance is superior to that of other works. Multi-level structure characterization suggests that the enhanced stability of the orthorhombic phase strengthens the antiferroelectricity and P_max, and the PE_MCC phase elicited by compositional inhomogeneity can reduce the hysteresis loss to optimize η. Most importantly, the induced strong localized fluctuations of strain at the nanoscale alter the energy barrier distribution, promoting the formation of nano-domain structure and polar nanoregions (PNRs), which significantly increased W_rec and η under low electric fields. These results represent a breakthrough in balancing the reduced working electric field and energy storage density as well as efficiency. The study proposes a novel paradigm for designing high energy storage performance ceramics under low electric fields, holding critical significance for next-generation pulse power systems and compact electronics.