Abstract

With the recent development of wearable/portable electronic devices, the power sources need to be flexible and miniaturized. As the power supply, a dielectric capacitor is used for systems requiring high power in a short time, which in turn necessitates dielectric materials with high energy density and fast discharging time for device miniaturization. In this study, we attempt to improve the energy density of organic materials by blending normal ferroelectric P(VDF-HFP), which offers high dielectric breakdown strength, and relaxor ferroelectric P(VDF-TrFE-CFE), which provides a high dielectric constant. The role of P(VDF-HFP) as a defect in the P(VDF-TrFE-CFE) crystallite improved the properties of the relaxor-ferroelectrics. Increasing the terpolymer content in the blended films reduced the normal ferroelectric β-phase, which revealed that non-polar phase was induced. The copolymer and terpolymer were blended in various weight ratios (10:0, 7:3, 5:5, 3:7, 1:9 and 0:10) and cast into films. The blends with a copolymer/terpolymer ratio of 1:9 showed reduced hysteresis and remnant polarization, compared to those of the pure terpolymer, and a higher maximum polarization (P_max) value at an electric field of 250 MV/m, indicating a less saturated polarization at high electric field. To conclude, the PVDF-based copolymer/terpolymer (1:9 ratio) blends showed the highest energy density (6.58 J/cm³).

Graphic Abstract

抽象的

随着可穿戴/便携式电子设备的最新发展，电源需要灵活且小型化。作为电源，在短时间内需要高功率的系统中使用介电电容器，这又需要具有高能量密度和快速放电时间的介电材料，以使器件小型化。在这项研究中，我们尝试通过掺混提供高介电击穿强度的普通铁电P（VDF-HFP）和提供高介电常数的弛豫铁电P（VDF-TrFE-CFE）来提高有机材料的能量密度。P（VDF-HFP）作为P（VDF-TrFE-CFE）晶体中的缺陷的作用改善了弛豫铁电体的性能。增加共混膜中的三元共聚物含量会降低正常的铁电β相，这表明诱导了非极性相。将共聚物和三元共聚物以各种重量比（10：0、7：3、5：5、3：7、1：9和0:10）共混并流延成薄膜。与纯三元共聚物相比，共聚物/三元共聚物比例为1：9的共混物显示出降低的磁滞和残余极化，并且具有更高的最大极化率（在250 MV / m的电场下的P _max值表示在高电场下的饱和极化较小。总之，基于PVDF的共聚物/三元共聚物（比例为1：9）的混合物显示出最高的能量密度（6.58 J / cm ³）。

图形摘要