Abstract
Developing high-performance film dielectrics for capacitive energy storage has been a great challenge for modern electrical devices. Despite good results obtained in lead titanate-based dielectrics, lead-free alternatives are strongly desirable due to environmental concerns. Here we demonstrate that giant energy densities of ~70 J cm-3, together with high efficiency as well as excellent cycling and thermal stability, can be achieved in lead-free bismuth ferrite-strontium titanate solid-solution films through domain engineering. It is revealed that the incorporation of strontium titanate transforms the ferroelectric micro-domains of bismuth ferrite into highly-dynamic polar nano-regions, resulting in a ferroelectric to relaxor-ferroelectric transition with concurrently improved energy density and efficiency. Additionally, the introduction of strontium titanate greatly improves the electrical insulation and breakdown strength of the films by suppressing the formation of oxygen vacancies. This work opens up a feasible and propagable route, i.e., domain engineering, to systematically develop new lead-free dielectrics for energy storage.
| Original language | English |
|---|---|
| Article number | 1813 |
| Journal | Nature Communications |
| Volume | 9 |
| Issue number | 1 |
| Early online date | 8 May 2018 |
| DOIs | |
| Publication status | Published - Dec 2018 |
| Externally published | Yes |
Funding
This work was supported by Basic Science Center Project of NSFC under grant No. 51788104, and the Natural Science Foundation of China (Grant Nos. 51532003 and 51729201). Q.Z. and L.G. thank the National Program on Key Basic Research Project (Grant No. 2014CB921002), the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB07030200) and the Natural Science Foundation of China (Grant Nos. 51522212, 51421002, and 51672307). We thank Dr. Deyang Chen (South China Normal University) for helpful discussions on the AFM tests.