Electrostatic interaction bridges the charge transport kinetics and high-temperature capacitive energy storage performance of polymer dielectrics

The capacitive energy storage performance of polymer dielectrics degrades rapidly at elevated temperatures and electric fields owing to the exponential growth of conduction loss. The formation of conduction loss is mainly attributed to the transport of charge carriers in polymer dielectrics and at the dielectric/electrode interface, which is dominated by bulk-limited and electrode-limited conduction mechanisms, respectively. Establishing a strong electrostatic interaction, both attractive and repulsive, between guest charge carriers and host polymer dielectrics has been extensively employed to inhibit charge transport. The construction of electrostatic attraction interaction can be implemented by introducing deep traps in polymer dielectrics to capture the charge carriers and restrain their transport. In contrast, the electrostatic repulsion is based on the scattering effect of an electron-rich surface, which can effectively reduce the mobility of energetic electrons and change the path of charge transport. Unfortunately, a systematic summary of using electrostatic interaction to regulate charge transport is still lacking. In this review, we critically analyze the electrical conduction mechanisms in polymer dielectrics and summarize recent advances in the regulation of high-temperature capacitive energy storage performance by employing electrostatic attraction and repulsion, including the advantages and limitations. This review is concluded by highlighting the advantages and limitations of such approach, as well as challenges and future opportunities.