TY - JOUR
T1 - Grain size engineered lead-free ceramics with both large energy storage density and ultrahigh mechanical properties
AU - Yang, Zetian
AU - Gao, Feng
AU - Du, Hongliang
AU - Jin, Li
AU - Yan, Leilei
AU - Hu, Qingyuan
AU - Yu, Ying
AU - Qu, Shaobo
AU - Wei, Xiaoyong
AU - Xu, Zhuo
AU - Wang, Yan Jie
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2019/4
Y1 - 2019/4
N2 - Lead-free dielectric ceramics with both a high recoverable energy storage density (W rec ) and excellent mechanical performance are highly desirable for practical applications in next-generation advanced pulsed power capacitors (APPCs). However, lead-free dielectric ceramics exhibit low W rec owing to small breakdown strength (E b ) and poor mechanical properties because of their large pore size and low relative density, which restrict devices miniaturization and operation in severe environments. Here, we propose a new strategy, namely, grain size engineering, to develop K 0.5 Na 0.5 NbO 3 (KNN)-based ceramics with both an extremely high W rec and large mechanical properties. Interestingly, a large W rec of 2 J cm −3 was achieved in 0.9K 0.5 Na 0.5 NbO 3 -0.1BiFeO 3 (0.9KNN-0.1BF) ceramics at 206 kV cm −1 , which is superior to other lead-free dielectric ceramics under moderate electric fields (<220 kV cm −1 ). Encouragingly, the hardness (H) of 0.9KNN-0.1BF ceramics reached 2.45 GPa, which is approximately 5 times higher than that of pure KNN ceramics (0.45 GPa). Moreover, the bending strength (σ f ), elastic modulus (E) and compression strength (σ c ) of 0.9KNN-0.1BF ceramics are also enhanced by ~200% over those of pure KNN ceramics. Compared with other lead-free dielectric ceramics, grain size engineered 0.9KNN-0.1BF is the first high-performance ceramic material with both an exceptionally large W rec and ultrahigh mechanical properties, which can accelerate the practical use of APPCs. Most importantly, the findings in this work will not only provide a guideline for developing other lead-free dielectric ceramics with both extremely high energy storage properties and superior mechanical performance but also open a window to the mechanical properties of dielectric ceramics for APPCs.
AB - Lead-free dielectric ceramics with both a high recoverable energy storage density (W rec ) and excellent mechanical performance are highly desirable for practical applications in next-generation advanced pulsed power capacitors (APPCs). However, lead-free dielectric ceramics exhibit low W rec owing to small breakdown strength (E b ) and poor mechanical properties because of their large pore size and low relative density, which restrict devices miniaturization and operation in severe environments. Here, we propose a new strategy, namely, grain size engineering, to develop K 0.5 Na 0.5 NbO 3 (KNN)-based ceramics with both an extremely high W rec and large mechanical properties. Interestingly, a large W rec of 2 J cm −3 was achieved in 0.9K 0.5 Na 0.5 NbO 3 -0.1BiFeO 3 (0.9KNN-0.1BF) ceramics at 206 kV cm −1 , which is superior to other lead-free dielectric ceramics under moderate electric fields (<220 kV cm −1 ). Encouragingly, the hardness (H) of 0.9KNN-0.1BF ceramics reached 2.45 GPa, which is approximately 5 times higher than that of pure KNN ceramics (0.45 GPa). Moreover, the bending strength (σ f ), elastic modulus (E) and compression strength (σ c ) of 0.9KNN-0.1BF ceramics are also enhanced by ~200% over those of pure KNN ceramics. Compared with other lead-free dielectric ceramics, grain size engineered 0.9KNN-0.1BF is the first high-performance ceramic material with both an exceptionally large W rec and ultrahigh mechanical properties, which can accelerate the practical use of APPCs. Most importantly, the findings in this work will not only provide a guideline for developing other lead-free dielectric ceramics with both extremely high energy storage properties and superior mechanical performance but also open a window to the mechanical properties of dielectric ceramics for APPCs.
KW - Energy storage density
KW - Grain size engineering
KW - Mechanical properties
KW - Potassium-sodium niobate
UR - http://www.scopus.com/inward/record.url?scp=85061352731&partnerID=8YFLogxK
U2 - 10.1016/j.nanoen.2019.02.003
DO - 10.1016/j.nanoen.2019.02.003
M3 - 文章
AN - SCOPUS:85061352731
SN - 2211-2855
VL - 58
SP - 768
EP - 777
JO - Nano Energy
JF - Nano Energy
ER -