Improve the Temperature Stability of PVDF/PMMA Energy Storage Performance by Crosslinking

With the development of science and technology, energy storage capacitors are gradually developing towards miniaturization and high temperature. Recently, polyvinylidene fluoride (PVDF) has attracted wide attention due to its high dielectric contant and high energy storage density. However, the problems of high dielectric loss and low temperature stability restrict the application of polyvinylidene fluoride. In this paper, it is proposed to optimize the dielectric loss and breakdown strength of polyvinylidene fluoride-based energy storage materials by blending polymethyl methacrylate (PMMA) with high glass transition temperature and high breakdown strength performance. On this basis, the crosslinking agent 1,6-hexanediamine was used to realize the crosslinking of PVDF and PMMA to improve the temperature stability of the material. Through this scheme, the finally obtained crosslinked PVDF/PMMA (40/60) film has an energy storage density of 10.4–11.9 J/cm3 at 30–90 ℃, and efficiency of 79–88%, which are better than most dielectric polymers. Our work provides a solution for optimizing the temperature stability of the energy storage properties of polymer ferroelectric materials to achieve higher energy storage densities at higher temperatures.