High discharge efficiency and energy density for polymer composites filled with S-doped zinc oxide nanoparticles

Abstract

Inorganic-polymer nanocomposites consisting of sulfur doped zinc oxide nanoparticles (ZOS_nps) as fillers and poly(vinylidene fluoride) (PVDF) as the polymer matrix were prepared via the solution casting method. The energy storage behaviors of PVDF/ZOS nanocomposites were studied. The results indicated that the incorporation of ZOS_nps in the polymer matrix could effectively improve breakdown strength (Eb), resulting in greatly enhanced energy density (Ue) and discharge efficiency (η). The nanocomposite with 1 vol% of ZOS_nps shows an outstanding discharge energy density of 11.5 J cm−3 and maintains a high discharge efficiency of 68.7% at 4800 kV cm−1. This reason is that S-doped zinc oxide nanoparticles with isoelectronic hope traps suppress the interfacial polarization. The present work may offer a novel way to confine the movement of charges by introducing isoelectronic impurities in polymer nanocomposites.