Composition and Structure Optimized BiFeO3-SrTiO3 Lead-Free Ceramics with Ultrahigh Energy Storage Performance
Publication Name
Small
Abstract
Dielectric ceramic capacitors have attracted increasing attention as advanced pulsed power devices and modern electronic systems owing to their fast charge/discharge speed and high power density. However, it is challenging to meet the urgent needs of lead-free ceramics with superior energy storage performance in practical applications. Herein, a strategy for the composition and structural modification is proposed to overcome the current challenge. The lead-free ceramics composed of BiFeO3-SrTiO3 are fabricated. A low hysteresis and high polarization can be achieved via composition optimization. The experimental results and finite element simulations indicate that the two-step sintering method significantly influences the decrease in the grain size and improvement in the breakdown strength (EBDS). A high EBDS of ≈750 kV cm−1 accompanied by a large maximum polarization (≈40 µC cm−2) and negligible remanent polarization (<2 µC cm−2) contribute to the ultrahigh energy density and efficiency values of the order of 8.4 J cm−3 and ≈90%, respectively. Both energy density and efficiency exhibit excellent stability over the frequency range of 1–100 Hz and temperatures up to 120 °C, along with the superior power density of 280 MW cm−3, making the studied BiFeO3-SrTiO3 ceramics potentially useful for high-power energy storage applications.
Open Access Status
This publication is not available as open access
Funding Number
2015CB654601
Funding Sponsor
Ministry of Science and Technology of the People's Republic of China