Dielectric ceramic capacitors are essential for modern pulse-power and electronic systems due to their ultrahigh power density and rapid charge-discharge capability. However, a long-standing challenge has been the simultaneous achievement of high recoverable energy storage density (Wrec) and high efficiency (η) under moderate electric fields-a key requirement for practical applications in automotive electronics, renewable energy systems, and pulsed power platforms.
Now, a team of materials scientists led by Pu Mao from Nanchang Hangkong University and Tianyu Li from University of Science and Technology Beijing has developed a new strategy to overcome this hurdle. By constructing strongly polarizable nanodomains in lead-free Bi0.5Na0.5TiO3(BNT)-based ceramics, they achieved a record-high Wrec of 6.11 J/cm3 and an impressive efficiency η of 86% at a moderate electric field of 330 kV/cm-outperforming the vast majority of reported bulk dielectric ceramics under comparable conditions.
The team published their work in Journal of Advanced Ceramics on 24 March 2026.
"The key innovation lies in the formation of strongly polarizable nanodomains," said Prof. Pu Mao, the corresponding author. "Through deliberate multi-ion substitution – including Sm3+ doping-and precise regulation of the rhombohedral (R) to tetragonal (T) phase ratio, we enhanced random fields and weakened interdomain interactions. This disrupts long-range ferroelectric order, reduces polarization anisotropy, and significantly lowers the energy barrier for polarization rotation near structural boundaries."
The resulting nanoscale polar regions retain the matrix's intrinsic high polarity while enabling slim polarization-electric field (P-E) loops with an ultrahigh maximum polarization (Pmax) of 65.8 μC/cm2 and a very low remnant polarization (Pr) of 5.34 μC/cm2. The optimized composition, 0.98(BNSB)0.985S0.01T-0.02CMN, also exhibits refined grain size (~0.28 μm) and a dense microstructure, which collectively enhance the breakdown strength and suppress leakage current.
"Notably, while many previously reported systems achieve either high Wrec or high η, they often compromise the other parameter. Our optimized composition uniquely achieves both high Wrec and high η, representing a significant advancement in comprehensive energy storage performance," added Prof. Tianyu Li, co-corresponding author. "Our work demonstrates that engineering strongly polarizable nanodomains is a viable pathway to break the traditional trade-off between polarization and breakdown strength in lead-free dielectrics," said Prof. Pu Mao. "The achieved energy density and efficiency under moderate electric fields bring BNT-based ceramics a significant step closer to practical capacitor applications."
This research provides a new material design paradigm for next-generation energy storage devices, including automotive power electronics, renewable energy systems, and pulsed-power platforms.
Funding
The study was financially supported by the National Natural Science Foundation of China (No. 52202136, 52562019), the Natural Science Foundation of Jiangxi Province (No. 20232BAB204017), the State Key Laboratory of Electrical Insulation and Power Equipment (No. EIPE24203), Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices (No. EFMD2024002Z), China National Postdoctoral Program for Innovative Talents (No. BX20240035), China Postdoctoral Science Foundation (No. 2024M760202), and Graduate Innovation Special Fund of Jiangxi Province (No. YC2024-S607).
About Journal of Advanced Ceramics
Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen . JAC's 2024 IF is 16.6, ranking in Top 1 (1/34, Q1) among all journals in "Materials Science, Ceramics" category, and its 2024 CiteScore is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508
