TITLE:
Functionalization of Polypropylene with High Dielectric Properties: Applications in Electric Energy Storage
AUTHORS:
T. C. Mike Chung
KEYWORDS:
Capacitor; Dielectric; Energy Storage; Polypropylene; Functional Polyolefin
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.2 No.2,
May
11,
2012
ABSTRACT: Biaxial-oriented polypropylene (BOPP) thin films are currently used as dielectrics in state-of-the-art capacitors that show many advantages, such as low energy loss and high breakdown strength, but a limited energy density ( 600 MV/m. The PP-OH dielectric demonstrates a linear reversible charge storage behavior with high releasing energy density > 7 J/cm3 (2 - 3 times of BOPP) after an applied electric field at E = 600 MV/m, without showing any significant increase of energy loss and remnant polarization at zero electric field. On the other hand, a cross-linked polypropylene (x-PP) exhibits an ε ~ 3, which is independent of a wide range of temperatures and frequencies, slim polarization loops, high breakdown strength (E = 650 MV/m), narrow breakdown distribution, and reliable energy storage capacity > 5 J/cm3 (double that of state-of-the-art BOPP capacitors), without showing any increase in energy loss.