School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China.
Carbohydr Polym. 2020 Dec 1;249:116883. doi: 10.1016/j.carbpol.2020.116883. Epub 2020 Aug 10.
Flexible electrostatic capacitors have many potential applications in modern electric power systems. In this study, flexible cellulose-based dielectric films were prepared by compositing regenerated cellulose (RC) and one-dimensional BaTiO nanofiber (BTNF) via a simple and environmentally friendly process. To improve compatibility and distributional homogeneity of the fillers/matrix, BTNF was surface modified by dopamine to prepare the poly(dopamine) modified BTNF (PDA@BTNF). The obtained RC/PDA@BTNF composite films (RC-PDA@BTNF) possessed higher dielectric constant and breakdown strength than those of the RC and RC/BTNF composite films. In particular, RC/PDA@BTNF composite films with 2 vol% PDA@BTNF (RC-2PDA@BTNF) exhibited a high discharged energy density of 17.1 J/cm at 520 MV/m, which exceeded 40 % compared with that of RC-2BTNF at 460 MV/m. Meanwhile, RC-2PDA@BTNF could continuously work for more than 10,000 times with a high efficiency of 91 %. Furthermore, the composite films could maintain good dielectric properties for a long time when stored in vacuum condition (under 0.3 atm). Therefore, these flexible cellulose-based dielectric materials are promising in the field of novel high-performance film dielectric capacitors.
柔性静电电容器在现代电力系统中有许多潜在的应用。在这项研究中，通过一种简单且环保的工艺，将再生纤维素（RC）和一维钛酸钡纳米纤维（BTNF）复合制备了柔性纤维素基介电膜。为了提高填料/基体的相容性和分布均匀性，用多巴胺对 BTNF 进行了表面改性，制备了聚多巴胺改性 BTNF（PDA@BTNF）。所得的 RC/PDA@BTNF 复合膜（RC-PDA@BTNF）的介电常数和击穿强度均高于 RC 和 RC/BTNF 复合膜。特别是，含有 2 vol% PDA@BTNF（RC-2PDA@BTNF）的 RC/PDA@BTNF 复合膜在 520 MV/m 下表现出 17.1 J/cm 的高放电能量密度，比在 460 MV/m 下的 RC-2BTNF 高出 40 %。同时，RC-2PDA@BTNF 可以高效率地连续工作超过 10000 次，效率为 91 %。此外，当储存在真空条件下（0.3 个大气压以下）时，复合膜可以长时间保持良好的介电性能。因此，这些基于纤维素的柔性介电材料在新型高性能薄膜介电电容器领域具有广阔的应用前景。
