Poly(ether imide)-Based Composites with Ultrahigh Energy Storage Capability and Thermal Stability

Abstract

The polymer dielectric is a promising material for intelligent and energy-saving applications in modern electronic and power systems. However, there are many crucial drawbacks in the applications at elevated temperatures, such as high dielectric loss and low energy density. Herein, a method to enhance the thermal stability of the polymer dielectrics is presented, whereby SrTiO3 particles are introduced into poly­(ether imide) (PEI) film to fabricate polymer-based dielectric composites. SrTiO3 is preferred as the filler for its moderate dielectric constant and wide band gap, which simultaneously restrains the leakage current density of the composites. The results show that the composite dielectric loaded with 3 vol % SrTiO3 particles achieves a discharge energy density of 11.30 J/cm3 at 640 MV/m. Furthermore, it exhibits the highest energy density of 10.30 J/cm3 at 150 °C and 530 MV/m, while the discharge energy density and efficiency remain 8.82 J/cm3 and 80% under 500 MV/m at 150 °C, respectively. The composites exhibit excellent fatigue resistance, and the discharge energy density is maintained at 96.21% with an efficiency of 95.96% after 105 charge–discharge cycles at 150 °C. This work elaborates the feasibility of adding SrTiO3 particles into PEI to enhance high-temperature capacitive properties and the great potential for extensive industrial production.

Improved High-Temperature Polarization and Charge–Discharge Efficiency in Fluorinated Polyimide Copolymers

“…This accumulation of Joule heating caused by loss will increase the environmental temperature of the device. The introduction of fluorinated dianhydride monomer plays a positive role in the decrease of leakage current at high temperatures. , The current density of FPI is much lower than that of the PI film at 150 °C, which is due to the strong electronegativity and electron affinity of fluorine atoms hindering the transportation of carriers.…”

Effect of AgNbO3 Morphology on Dielectric and Energy Storage Properties of Polyvinylidene Fluoride-Based Nanocomposites

“…Under the influence of slight differences in bond length and bond angle, the lattice parameters a and c of C-AN, S-AN, and H-AN increase in turn and b decreases in turn. Compared with the lattice parameters a and b, the change of c is more obvious, which is 15.6576(4), 15.6651 (7), and 15.7188(1) Å, respectively. Therefore, the cell volume of the C-AN particle is the smallest (487.61(4) Å 3 ), followed by the S-AN particle (487.65(1) Å 3 ), and the cell volume of the H-AN particle is the largest (489.03(3) Å 3 ).…”

“…Increasing the content of the β phase is very beneficial to the dielectric and FE properties of PVDF, which can improve the energy storage performance of composites . By introducing high dielectric constant ceramics into PVDF as inorganic fillers, it is hoped that the breakdown strength and polarization strength of the composite can be improved without reducing the dielectric constant, and the dielectric loss can be maintained at a low level, thus improving the energy storage density of the composite. − …”