posted on 2024-01-09, 14:14authored byTianyu Li, Shiqing Deng, Ruixue Zhu, Jiyuan Yang, Shiqi Xu, Yongqi Dong, Hui Liu, Chuanrui Huo, Peng Gao, Zhenlin Luo, Oswaldo Diéguez, Houbing Huang, Shi Liu, Long-Qing Chen, He Qi, Jun Chen
Dielectric
capacitors are highly desired in modern electronic devices
and power systems to store and recycle electric energy. However, achieving
simultaneous high energy density and efficiency remains a challenge.
Here, guided by theoretical and phase-field simulations, we are able
to achieve a superior comprehensive property of ultrahigh efficiency
of 90–94% and high energy density of 85–90 J cm–3 remarkably in strontium titanate (SrTiO3), a linear dielectric of a simple chemical composition, by manipulating
local symmetry breaking through introducing Ti/O defects. Atomic-scale
characterizations confirm that these Ti/O defects lead to local symmetry
breaking and local lattice strains, thus leading to the formation
of the isolated ultrafine polar nanoclusters with varying sizes from
2 to 8 nm. These nanoclusters account for both considerable dielectric
polarization and negligible polarization hysteresis. The present study
opens a new realm of designing high-performance dielectric capacitors
utilizing a large family of readily available linear dielectrics with
very simple chemistry.