High-performance dielectrics are widely used in high-power systems,electric vehicles,and aerospace,as key materials for capacitor devices.Such application scenarios under these extreme conditions require ultra-high st...High-performance dielectrics are widely used in high-power systems,electric vehicles,and aerospace,as key materials for capacitor devices.Such application scenarios under these extreme conditions require ultra-high stability and reliability of the dielectrics.Herein,a novel pyrochlore component with high-entropy design of Bi1.5Zn_(0.75)Mg_(0.25)Nb_(0.75)Ta_(0.75)O_(7)(BZMNT)bulk endows an excellent energy storage performance of Wrec≈2.72 J/cm3 together with an ultra-high energy efficiency of 91%at a significant enhanced electric field Eb of 650 kV/cm.Meanwhile,the temperature coefficient(TCC)of BZMNT(~−220 ppm/℃)is also found to be greatly improved compared with that of the pure Bi1.5ZnNb1.5O7(BZN)(~−300 ppm/℃),demonstrating its potential application in temperature-reliable conditions.The high-entropy design results in lattice distortion that contributes to the polarization,while the retardation effect results in a reduction of grain size to submicron scale which enhances the Eb.The high-entropy design provides a new strategy for improving the high energy storage performance of ceramic materials.展开更多
基金This work was supported by the National Key R&D Program of China(Grant No.2021YFB3800601)the Basic Science Center Project of the National Natural Science Foundation of China(Grant No.51788104).
文摘High-performance dielectrics are widely used in high-power systems,electric vehicles,and aerospace,as key materials for capacitor devices.Such application scenarios under these extreme conditions require ultra-high stability and reliability of the dielectrics.Herein,a novel pyrochlore component with high-entropy design of Bi1.5Zn_(0.75)Mg_(0.25)Nb_(0.75)Ta_(0.75)O_(7)(BZMNT)bulk endows an excellent energy storage performance of Wrec≈2.72 J/cm3 together with an ultra-high energy efficiency of 91%at a significant enhanced electric field Eb of 650 kV/cm.Meanwhile,the temperature coefficient(TCC)of BZMNT(~−220 ppm/℃)is also found to be greatly improved compared with that of the pure Bi1.5ZnNb1.5O7(BZN)(~−300 ppm/℃),demonstrating its potential application in temperature-reliable conditions.The high-entropy design results in lattice distortion that contributes to the polarization,while the retardation effect results in a reduction of grain size to submicron scale which enhances the Eb.The high-entropy design provides a new strategy for improving the high energy storage performance of ceramic materials.
