Asymmetric Trilayer All‐Polymer Dielectric Composites with Simultaneous High Efficiency and High Energy Density: A Novel Design Targeting Advanced Energy Storage Capacitors

Abstract

Polymeric dielectrics have attracted intensive attention worldwide because of their huge potential for advanced energy storage capacitors. Thus far, various effective strategies have been developed to improve the inherent low energy densities of polymer dielectrics. However, enhanced energy density is always accompanied by suppressed discharge efficiency, which is detrimental to practical applications and deserves considerable concern. Targeting at achieving simultaneous high energy density and high discharge efficiency, the unique design of asymmetric all-polymer trilayer composite consisting of a transition layer sandwiched by a linear dielectric layer and a nonlinear dielectric layer is herein reported. It is demonstrated that the nonlinear dielectric layer offers high energy density, while the linear dielectric layer provides high discharge efficiency. Especially, the transition layer can effectively homogenize the electric field distribution, resulting in greatly elevated breakdown strength and improved energy density. In particular, a high efficiency of 89.9% along with a high energy density of 12.15 J cm −3 are concurrently obtained. The asymmetric trilayer all-polymer design strategy represents a new way to achieve high-performance dielectric energy storage materials.

Epsilon-negative behavior and its capacitance enhancement effect on trilayer-structured polyimide–silica/multiwalled carbon nanotubes/polyimide–polyimide composites

“…The main reason is the introduction of MWCNTs, with the transition of electrons in the composites from hopping conduction to metal-like conduction. [43][44][45][46] Indeed, such mitigated electrical conduction indicates the important role of insulating SiO 2 particles as effective impediments for the tunneling of electrons. Meanwhile, the AC conductivity of single-layer composites has very little dependence on frequency.…”

Energy Storage Application of All-Organic Polymer Dielectrics: A Review

“…( g ) Schematic illustration of the dielectric energy-storage characteristics of the LTN structure; ( h ) Comparison of breakdown strength of PEI, P(VDF-HFP), single-layer PEI/P(VDF-HFP) blend composites, PEI-P(VDF-HFP) bilayer composite, and asymmetric trilayer composites; ( i ) The radar plots of the E-20 vol% E/F-F asymmetric trilayer composite. Reprinted with permission from [ 140 ]. Copyright (2021), Wiley.…”

“…Polarization at the interfaces between the layers increased the energy storage density even more. The addition of linear polymer PEI significantly decreased the conduction loss ( L c ) and ferroelectric loss ( L f ) of the composite material, resulting in a higher energy density of 12.15 J/cm 3 and an efficiency of 89.9% ( Figure 14 i) [ 140 ].…”

Improved magnetic properties of iron-based soft magnetic composites with a double phosphate-SiO2 shells structure

“…According to different application requirements, different metal magnetic base materials can be used for SMCs. Due to the advantages of high initial permeability, stable permeability, excellent DC magnetic bias, and low price, pure iron powder core is widely used in low-end electronic products such as transformer, filter, inductor, rectifier coil [3][4][5], etc.…”