Open AccessStructure design boosts concomitant enhancement of permittivity, breakdown strength, discharged energy density and efficiency in all‐organic dielectrics
Author(s) -
Dan Zhenkang,
Ren Weibin,
Guo Mengfan,
Shen Zhonghui,
Zhang Tao,
Jiang Jianyong,
Nan Cewen,
Shen Yang
Publication year - 2020
Publication title -
iet nanodielectrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.23
H-Index - 9
ISSN - 2514-3255
DOI - 10.1049/iet-nde.2020.0034
Subject(s) - materials science , composite material , nanocomposite , permittivity , dielectric , composite number , capacitor , optoelectronics , electrical engineering , voltage , engineering
Polymer‐based nanocomposites with excellent flexibility and intrinsic high breakdown strength are promising candidates for high energy density capacitors compared to ceramics counterparts. However, their energy density is relatively low due to the trade‐off between permittivity and breakdown strength. In this work, the authors proposed a ferroconcrete‐like structure for all‐organic nanocomposites via combinatorial electrospinning and hot‐pressing method. In this structure, polymethyl methacrylate (PMMA) serves as matrix while poly(vinylidene fluoride‐co‐hexafluoropropylene) (P(VDF‐HFP)) serves as reinforcement phase. This novel structure is highly effective in breaking the paradox of improved discharged energy density with decreased efficiency, as evidenced by the concurrently improved discharged energy density (∼12.15 J/cm 3 compared to 8.82 J/cm 3 of the matrix) and efficiency (∼81.7% compared to 76.8% of the matrix). Compared to conventional blending composite films, samples with ferroconcrete‐like structure exhibit higher permittivity, breakdown strength, discharged energy density and efficiency. The superior energy storage performance is attributed to large aspect ratio P(VDF‐HFP) fibres distributed perpendicularly to the external field, which brings about the extra enhancement of permittivity. Besides, mechanical properties are improved and restriction on carrier motion is facilitated, leading to enhanced breakdown strength and suppressed conduction. This work provides a new way to design dielectric composite for high energy density and efficiency applications.