Research progress on crosslinked polymer-based dielectrics for thin film capacitors

Polymer dielectric materials possess advantages of high breakdown strength, low dielectric loss and easily to processing, etc., thus attract wide attention and play a crucial role in modern electronic industry and advanced energy storage applications. However, at high temperature, the energy storage density and efficiency of polymer dielectric decrease significantly and cannot meet practical application requirements. Crosslinking strategy is considered as one of the most feasible methods for polymer dielectric to meet high temperature requirements. This article mainly reviews the research progress in recent years on the preparation of PVDF dielectric polymers with crosslinking structure using physical crosslinking methods (hydrogen bonding crosslinking), chemical crosslinking methods (photo-crosslinking, thermal crosslinking, self-crosslinking), and physical-chemical dual crosslinking methods. The different principles and process methods for obtaining PVDF dielectric polymers with crosslinking structure were summarized, and the dielectric properties of crosslinked and uncrosslinked PVDF polymers were compared. It was found that PVDF dielectric polymers with a crosslinking structure have good energy storage density and charge-discharge efficiency, and have excellent dielectric properties at high temperatures. This provides a strategy and process method for exploring high-performance polymer dielectric materials suitable for new electronic devices under high-temperature conditions.