All-organic siloxane strengthening polymer dielectric for high-temperature capacitive energy storage at harsh-environment electronics

Dielectric polymer films often suffer from poor energy-storage level in harsh-environment electronic devices, circuits and systems. In this work, a molecular engineering strategy is described to synergistically achieve high mechanical strength (321 MPa), breakdown strength (726 MV/m) and energy density/efficiency (6.5 J/cm³ at η=90%) at 150℃ in fabricated all-organic siloxane strengthening polyamide film, whose comprehensive performances present obvious preponderance in existed polymer dielectrics. It is demonstrated that the particular coexistence of strong hydrogen bond, large energy gap and siloxane unit specifically reducing interchain interactions in constraint space, rather than traditionally limitless reduction, synergistically strengthens energy-storage and mechanical performances. Meanwhile, once confronting harsher partial corona discharge in some particular application scenarios, the copolymerized siloxane unit can in-situ generate SiO₂-like structure to effectively resist direct and persistent damage of corona discharge, thereby maintaining high energy-storage level. This work explores a valuable all-organic design route to synergistically strengthen the high-temperature energy storage performance, mechanical strength and partial corona discharge resistance ability of polymer dielectrics, which also presents large-scale production superiority of fabricating high-quality polymer dielectrics toward harsh-environment applications in electronics.