Yu Dan,Haojie Xu,Yangyang Zhang,Kailun Zou,Qingfeng Zhang,Yinmei Lu,Gang Chang,Qi Zhang,Yunbin He
Lead lanthanum zirconate stannate titanate (PbLa(ZrSnTi)O 3 ) antiferroelectric (AFE) ceramics are widely used in dielectric capacitors due to their superior energy-storage capacity. Generally, these ceramics can be synthesized by solid-state reaction and sol-gel methods. Ceramics prepared using the sol-gel method have a purer phase than those prepared using the solid-state reaction method because the sol-gel method can avoid the segregation of Sn. However, because the commonly used raw material tin acetate is very expensive, the preparation of PbLa(ZrSnTi)O 3 AFE ceramics via the sol-gel method is not cost-effective, which prevents the use of sol-gel method for manufacturing PbLa(ZrSnTi)O 3 in a large scale. In this work, low-cost dibutyltin oxide instead of expensive tin acetate is used to synthesize Pb 0.97 La 0.02 (Zr 0.50 Sn 0.45 Ti 0.05 )O 3 (PLZST) nanopowders, and single-phase powders with a perovskite structure and average grain size of 200 nm are obtained at a calcination temperature of 580°C. In addition, dense PLZST AFE ceramics with a pure perovskite structure are obtained by sintering the PLZST nanopowders at temperatures as low as 1100°C. The sintered PLZST ceramics exhibit a room-temperature recoverable energy-storage density as high as 1.93 J/cm 3 with an efficiency of 75%, which varies only slightly in the temperature range of 20-120°C. The high energy-storage density (>1.9 J/cm 3 ) over a wide temperature range illustrates that the sol-gel-derived PLZST ceramics with low-cost dibutyltin oxide are quite promising for manufacturing pulse power capacitors.
Kailun Zou,Yu Dan,Yuxi Yu,Ying Zhang,Qingfeng Zhang,Yinmei Lu,Haitao Huang,Xin Zhang,Yunbin He
Dielectric nanocomposites composed of a polymer matrix with high electric breakdown strength and inorganic ferroelectric nanofillers with large maximum electric displacement (Dmax) have recently attracted much attention due to their high power density, superior flexibility, and good fatigue endurance. However, their discharge energy density and energy efficiency are limited because of the high remnant displacement (Dr) and small Dmax − Dr values of the ferroelectric fillers. Compared with ferroelectrics, antiferroelectrics exhibit much lower Dr (near zero) and far larger Dmax − Dr values, and thus if they are used as the fillers of the dielectric composite, a larger discharge energy density and higher energy efficiency may be obtained simultaneously. Based on this, in this work, Pb0.97La0.02(Zr0.50Sn0.45Ti0.05)O3 (PLZST) antiferroelectric nanoparticles (∼200 nm in diameter) coated with a dense and robust dopamine layer are prepared in order to develop dopamine-modified PLZST filler/poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) polymer nanocomposites with superior energy storage properties. The experimental results indicate that optimizing the filler content leads to a small Dr (0.61 μC cm−2), large Dmax − Dr value (6.14 μC cm−2), and high electric breakdown strength (3136 kV cm−1), as a result of which, the PLZST/P(VDF-HFP) nanocomposites filled with 5 wt% dopamine-modified PLZST nanoparticles simultaneously exhibit a large discharge energy density of 9.39 J cm−3 and high energy efficiency of 82%. These energy storage properties are superior to those of most ferroelectric filler (including nanowires and nanofibers prepared by complicated methods)/polymer nanocomposites with a single-layer structure. Our work not only proves that, antiferroelectric nanoparticles are excellent fillers that can be comparable to, or even better than, ferroelectric nanowires and nanofibers prepared by very complicated methods, for energy-storage inorganic/polymer dielectric composites, but also provides a convenient and effective way to prepare and design flexible dielectric capacitors with superior energy storage capacity.