Polymer Dielectrics with Simultaneous Ultrahigh Energy Density and Low Loss

Abstract

Polymer dielectrics are highly desirable in capacitor applications due to their low cost, high breakdown strength, and unique self-healing capability. However, existing polymer dielectrics suffer from either a low energy density or a high dielectric loss, thereby hindering the development of compact, efficient, and reliable power electronics. Here, a novel type of polymer dielectrics simultaneously exhibiting an extraordinarily high recoverable energy density of 35 J cm −3 and a low dielectric loss is reported. It is synthesized by grafting zwitterions onto the short side chains of a poly(4-methyl-1-pentene) (PMP)-based copolymer, which increases its dielectric constant from ≈2.2 to ≈5.2 and significantly enhances its breakdown strength from ≈700 MV m −1 to ≈1300 MV m −1 while maintaining its low dielectric loss of <0.002 and high charge-discharge efficiency of >90%. Based on a combination of the phase-field method description of mesoscale structures, Maxwell equations, and theoretical analysis, it is demonstrated that the outstanding combination of high energy density and low dielectric loss of zwitterions-grafted copolymers is attributed to the covalent-bonding restricted ion polarization and the strong charge trapping by the zwitterions. This work represents a new strategy in polymer dielectrics for achieving simultaneous high energy density and low dielectric loss.

High Breakdown Strength and Energy Storage Density in Aligned SrTiO3@SiO2 Core–Shell Platelets Incorporated Polymer Composites

“…The Weibull distribution of PVDF and composites with SrTiO 3 @SiO 2 platelets analyzed by adopting the Weibull statistics [24]:…”

Prediction of Energy Storage Performance in Polymer Composites Using High‐Throughput Stochastic Breakdown Simulation and Machine Learning

“…[ 5 , 6 , 7 , 8 ] Energy storage density is an important factor in the polymer dielectric capacitors. [ 9 , 10 , 11 ] Generally, the energy storage density ( U ) of dielectrics can be approximately predicted via following expression as U = 1/2 ε r ε 0 E 2 , where ε r is the relative dielectric constant, ε 0 is the vacuum dielectric constant (8.85 × 10 −12 F m −1 ) and E is the applied electric field. Figure S1 (Supporting Information) can be seen more intuitively that U is governed by two factors of polarization ( P ) and E in the Supporting Information, the P ’s strength is closely related to the ε r .…”

Research Progress on Multilayer‐Structured Polymer‐Based Dielectric Nanocomposites for Energy Storage

“…It can be obtained as U s = ∫ EdD, which can be determined by the electric displacement (D) and the applied electric field (E). [13][14][15][16][17][18] For ideal linear dielectrics, the energy loss due to leakage conduction is assumed to be zero in the charge and discharge processes because 𝜖 r does not vary with E. The U e of linear dielectrics is related to E and 𝜖 r , as follows: U s = 1 2 𝜀 r 𝜀 0 E 2 , where 𝜖 0 = 8.85 × 10 −12 Fm −1 is the vacuum permittivity. For nonlinear dielectrics, there is always an energy loss issue during the charging and discharging processes.…”

“…For nonlinear dielectrics, there is always an energy loss issue during the charging and discharging processes. [1,[19][20][21][22][23][24][25] The charging-discharging efficiency (𝜂) of dielectrics is defined as…”