Excellent energy storage performance of multi-alternating-layer structured PMMA/PVDF dielectric composite at high-temperature

Abstract

Polymer dielectric capacitors have high power density and are an integral component of electronic and power device. Currently, the limited energy density restricts their further application. In this research, a novel method was designed to optimize performance of PMMA/PVDF composite via an alternating stacked multi-layer structure. And, the five-alternating-layer of PVDF-PMMA-PVDF-PMMA-PVDF (F-A-F-A-F) composite has excellent dielectric properties, for instance, a better dielectric constant (4.52@1 kHz) and a low dielectric loss (0.034@1 kHz). The discharge energy density (U_e) of it is significantly larger than that of PMMA and PVDF. Particularly, the U_e of F-A-F-A-F composite is increased by 83.0 % (from 4.71 J/cm³ to 8.62 J/cm³) with charging-discharging efficiency of 60 % at 80 °C. Moreover, the F-A-F-A-F composite achieves an excellent stability after 40,000 cycles. This composite has a wide range of potential applications in the field of traditional dielectric capacitor due to its good energy storage performance and cycle stability.