Giant permittivity materials with low dielectric loss over a broad temperature range enabled by weakening intermolecular hydrogen bonds

High-temperature polymer dielectrics are of great interest for next generation capacitors demanded in harsh-environment electronics and electrical-power applications. Although some high-T_g engineering polymers have been considered as possible high-temperature dielectric materials, the low permittivity has significantly limited their development. Hence it is still a great challenge in dielectric polymers to achieve a high permittivity while maintain low dielectric loss over a broad temperature range. Here we report a highly scalable and low cost strategy to develop such high-performance polymer dielectrics. Two high-T_g glassy state dipolar polymers, i.e., poly(ether imide) and poly(ether-methyl-ether-urea) are blended by properly engineered to increase dipole mobility in polymer chains caused by combined effects of disruption of hydrogen bonds and improved free volume for dipoles in the glassy state blend. Consequently, such polymer blend displays thermally stable dielectric properties with an intrinsic giant permittivity of 5.8 and low dielectric loss (<1%) over a broad temperature.