摘要
Both sustainable development in environment and safety of high-power systems require to develop a novel lead-free dielectric capacitor with high energy density(Wrec)at low applied electric field.In this work,a remarkably high Wrec of 2.9 J/cm^(3) accompanying with energy storage efficiency of 56% was achieved in Ag_(0.9)Sr_(0.05)NbO_(3) ceramic at a low applied electric field of 190 kV/cm,by improving antiferroelectricity and introducing relaxor behaviour.The improved anti-ferroelectric stability was attributed to the decreased tolerance factor and average electronegativity difference,while the relaxor behaviour was associated with the increased disordered local structure by Sr-doping.Moreover,the Ag_(0.9)Sr_(0.05)NbO_(3) ceramics also exhibited outstanding temperature stability in energy density with small variation less than 5% over 20-140℃.The results indicate that the Ag_(0.9)Sr_(0.05)NbO_(3) ceramic is a promising candidate for low-electric-field driving capacitors.
基金
supported by National Natural Science Foundation of China(Grants 11864004)
Guangxi Natural Science Foundation(Grants 2017GXNSFBA198132,2016GXNSFAA380214,2016GXNSFCB380006 and 2017GXNSFFA198015)
Science and Technology Major Project of Guangxi,(Grant AA17204100)
Innovation Project of Guangxi Graduate Education(Grant YCSW2019053)
the funds of the State Key Laboratory of New Ceramics and Fine Processing,Tsinghua University,Beijing(100084),China.
