In this work,we show that a d_(33)~150 pC/N can be obtained in nonpoled poly(vinylidene fluoride trifluoroethylene)(P(VDF-TrFE))copolymer films with an arch structure.The copolymer films,which are often thought to be ...In this work,we show that a d_(33)~150 pC/N can be obtained in nonpoled poly(vinylidene fluoride trifluoroethylene)(P(VDF-TrFE))copolymer films with an arch structure.The copolymer films,which are often thought to be homogeneous,are in fact inhomogeneous in microstructure and physical properties after film fabrication.Although a large proportion of the copolymer film is nonpolar,as expected in a nonpoled ferroelectric film,the surface regions of the film are spontaneously polarized.We propose that inhomogeneous stress in the surface regions,which is either from the constraint of the substrate or skin layer effect formed during the film fabrication,generates a flexoelectric response and orients the spontaneous polarization of the ferroelectric film.As a result of the polar surface regions,the nonpoled films exhibit a piezoelectric response.The piezoelectric response is further amplified by the special arch structure of the films,leading to the observed large effective piezoelectric response.This study not only discovers the polar surface effect in ferroelectric polymer films,but also proposes an approach to design polymer materials with a strong piezoelectric response.展开更多
Capacitors are critical components in many advanced electronic and electrical systems,such as pulse power systems,due to their fast charging-discharging speed and high power density[1-4].The ever-increasing demand for...Capacitors are critical components in many advanced electronic and electrical systems,such as pulse power systems,due to their fast charging-discharging speed and high power density[1-4].The ever-increasing demand for compact energy storage devices requires the dielectrics,which are the energy storage materials in capacitors,to have a higher energy density and low dielectric loss[2,3].Furthermore,a stable high-temperature performance is another important parameter to be considered for some applications in which high-temperature conditions are present,such as hybrid vehicles[4-7].展开更多
基金supported by the National Key Research and Development Program of China(Nos.2017YFA0701301 and 2020YFA0711502).
文摘In this work,we show that a d_(33)~150 pC/N can be obtained in nonpoled poly(vinylidene fluoride trifluoroethylene)(P(VDF-TrFE))copolymer films with an arch structure.The copolymer films,which are often thought to be homogeneous,are in fact inhomogeneous in microstructure and physical properties after film fabrication.Although a large proportion of the copolymer film is nonpolar,as expected in a nonpoled ferroelectric film,the surface regions of the film are spontaneously polarized.We propose that inhomogeneous stress in the surface regions,which is either from the constraint of the substrate or skin layer effect formed during the film fabrication,generates a flexoelectric response and orients the spontaneous polarization of the ferroelectric film.As a result of the polar surface regions,the nonpoled films exhibit a piezoelectric response.The piezoelectric response is further amplified by the special arch structure of the films,leading to the observed large effective piezoelectric response.This study not only discovers the polar surface effect in ferroelectric polymer films,but also proposes an approach to design polymer materials with a strong piezoelectric response.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFA0701301)the National Natural Science Foundation of China(Grant Nos.51373161,and 51672261)
文摘Capacitors are critical components in many advanced electronic and electrical systems,such as pulse power systems,due to their fast charging-discharging speed and high power density[1-4].The ever-increasing demand for compact energy storage devices requires the dielectrics,which are the energy storage materials in capacitors,to have a higher energy density and low dielectric loss[2,3].Furthermore,a stable high-temperature performance is another important parameter to be considered for some applications in which high-temperature conditions are present,such as hybrid vehicles[4-7].
