Polymer dielectrics for high-temperature energy storage: Constructing carrier traps

Film capacitors are essential components used for electrical energy storage in advanced high-power electrical and electronic systems. High temperature environments place exacting demands on the polymer dielectrics of film capacitors. The nonlinear increase in conduction of polymer dielectrics at elevated temperatures leads to deterioration of the energy storage characteristics. Effectively suppressing conduction is therefore the fundamental challenge. Carrier traps are effective in suppressing conduction and have a variety of designs that can be combined with special structures, making them widely available for high temperature energy storage. Herein, we present a critical overview of recent research advances and important insights in understanding the carrier traps in polymer dielectrics. First, the basic theory of carrier traps is systematically summarized. The strategies for constructing carrier traps are then described from three perspectives: intrinsic structures, inorganic/polymer composites, and all-organic composites. Finally, the key points of carrier traps in dielectric energy storage are summed up and the future development trends are prospected.