High-temperature energy storage polyimide dielectric materials: polymer multiple-structure design

Polymer dielectrics have been proved to be critical materials for film capacitors with high energy density. However, the harsh operating environment requires dielectrics with high thermal stability, which is lacking in commercial dielectric film. Polyimide (PI) is considered a potential candidate for high-temperature energy storage dielectric materials due to its excellent thermal stability and insulating properties. This review expounds on the design strategies to improve the energy storage properties of polyimide dielectric materials from the perspective of polymer multiple structures, including short-range structures, remote structures and higher-order structures. The introduction of highly polar groups, the regulation technology of different molecular segment structures and the blending method of all-organic polyimide are discussed in depth. The development of computational simulation methods in high-temperature energy storage polyimide dielectrics is also presented. Finally, the key problems faced by using polyimide as a high-temperature energy storage dielectric material are summarized, and the future development direction is explored.