Improved energy storage property in polyvinylidene fluoride‐based multilayered composite regulated by oriented carbon nanotube@SiO₂ nanowires

Abstract

High‐performance dielectric capacitors are essential components of advanced electronic and pulsed power systems for energy storage. Because of their high breakdown strength and excellent flexibility, polymer‐based capacitors are regarded as auspicious energy storage material. However, the energy storage capacity of polymer‐based capacitors is severely limited due to their low polarisation and low dielectric permittivity. The modified Stöber method was used to construct two types of CNT@SiO2 (CS) one‐dimensional core‐shell structured nanowires with different shell thicknesses. By integrating the procedures of solution mixing, melt blending, hot‐stretching orientation and hot pressing, sandwich‐structured poly (vinylidene fluoride) (PVDF)‐based composites were fabricated. The CS core‐shell nanowires dispersed in the inter‐layer serve as electron donors, leading to a high permittivity, while two PVDF outer layers provide the favourable overall breakdown strength. The insulating SiO2 shell can effectively limit the migration of carriers and keep the dielectric loss at a relatively low level in the composites. The CS/PVDF composite exhibited an enhanced discharged density (~6.1 J/cm3) and breakdown strength (~241 kV/mm) when the interlayer filled with as small as 1 wt% CS nanowires with the SiO2 shell thickness of 8 nm, which is 203% and 18.7 % higher than pure PVDF (~2.01 J/cm3 at 203 kV/mm), respectively. This research presents a practical strategy for designing and fabricating advanced polymer film capacitor energy storage devices.

Improved electro‐actuation property of dielectric elastomer composites regulated by one‐dimensional CaCu3Ti4O12@TiO2 core–shell construction

“…In recent years, researchers evidenced that an appropriate shell layer constructed between the high-ε r nanofillers and the low-ε r matrix was able to alleviate the overall dielectric mismatch in composites. 36 On one hand, the shell with moderate ε r acted as a buffer layer can make the actual electric field distribution more uniform and prevent the DE composites from being broken-down prematurely during the electro-actuation process. On the other hand, the additional shell layer could provide larger heterogeneous interfaces (core-shell and shellmatrix interfaces) as well as a stronger interfacial polarization for the composites, which is benefit to the improvement in ε r of the composites.…”

“…Consequently, alleviating the local electric field distortion is critical to improve the electro‐actuated performance and expand the safe‐operation range of DE composites. In recent years, researchers evidenced that an appropriate shell layer constructed between the high‐ ε r nanofillers and the low‐ ε r matrix was able to alleviate the overall dielectric mismatch in composites 36 . On one hand, the shell with moderate ε r acted as a buffer layer can make the actual electric field distribution more uniform and prevent the DE composites from being broken‐down prematurely during the electro‐actuation process.…”

Core@Double–Shell Engineering of Zn Particles toward Elevated Dielectric Properties: Multiple Polarization Mechanisms in Zn@Znch@PS/PVDF Composites

“…Additionally, the presence of multiple interfaces could facilitate IP subsequently leading to elevated 𝜖′ at low frequencies and promoting the contributions to 𝜖′ at highfrequency from core-shell components. [20] The large mismatch in electrical/dielectric properties between the polymer and the conductive fillers can be obviously mitigated by selecting different external shells that tailor the filler-polymer interfaces over a wide range, such as molybdenum trioxide, [2] nickel oxide, [10] aluminum nitride, [11] polystyrene (PS), poly(vinyl pyrrolidone), and others. [4,[21][22][23] In comparison to often used metals like aurum (Au), silver (Ag), copper (Cu), and nickel (Ni), zinc (Zn) is a good candidate for polymeric composite dielectrics owing to its outstanding electric conductivity, relatively high TC, and inexpensive cost.…”

“…Additionally, the presence of multiple interfaces could facilitate IP subsequently leading to elevated ε ′ at low frequencies and promoting the contributions to ε ′ at high‐frequency from core–shell components. [ 20 ] The large mismatch in electrical/dielectric properties between the polymer and the conductive fillers can be obviously mitigated by selecting different external shells that tailor the filler–polymer interfaces over a wide range, such as molybdenum trioxide, [ 2 ] nickel oxide, [ 10 ] aluminum nitride, [ 11 ] polystyrene (PS), poly(vinyl pyrrolidone), and others. [ 4,21–23 ]…”

Polyetherimide nanocomposites filled with in‐situ synthesised bismaleimide‐DDE@CCTO hybrid nanofibers enabling improved dielectric and interfacial performance

“…However, there exist a great challenge to better balance the dielectric properties and inorganic-organic system compatibility since the most of past works focus more on the dielectric performance while weakening the study on interfacial adhesion characteristics [16][17][18]. Although some previous publications have already reported some amelioration in interfacial properties, there are still many tough issues to be further resolved, especially when the giant k fillers such as CCTO nanoparticles are used [19]. The poor compatibility of inorganic filler and organic matrix is the main drawback to be urgently ameliorated.…”