Dielectric And Energy Storage Properties Of Nanocomposites With Core-Shell Paraffin-Engineered Batio3 In Polyimides

In this work, PI was chosen as polymer matrix, PI composite films embedded with BaTiO3 were prepared by in-situ polymerization. BaTiO3 nanofillers were modified with paraffin to form a core-shell structure in order to improve the dispersion and compatibility with PI matrix. The permittivity of paraffin@BT/PI composite films with 40 wt% filler loading increase to 8.0 (1 kHz), which is about 2.4 times higher than that of pristine PI. The composites show stable capacitance in the range of 80 to180 degrees C. The energy storage density of composites with 40 wt% filler loading is as high as 3.31 J cm(-3) under 180 MV m(-1), which is 2.4 times higher than that of pristine PI (0.97 J cm(-3) at 180 MV m(-1)). However, the charge-discharge efficiency is 29.03%, and the discharge energy density is only 0.96 J cm(-3) at 180 MV m(-1). To weigh the pros and cons, the composites with 30 wt% filler loading exhibit a better energy storage property, with a eta of 70.45% (180 MV m(-1)) and discharge energy density of 1.03 J cm(-3) at 180 MV m(-1).