Epoxy-based/BaTiO3 nanodielectrics: Relaxation dynamics, charge transport and energy storage. (January 2022)

• Record Type: Journal Article
• Authors: Drakopoulos, Stavros X.; Patsidis, Anastasios C.; Psarras, Georgios C.
• Is Part Of: Materials research bulletin. Volume 145(2022)
• Publication Date: 2022-01
• Subjects: Epoxy resin -- Barium titanate -- Interfacial polarization -- Broadband dielectric spectroscopy -- Polymer nanodielectrics; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2021.111537
• Languages: English
• ISSNs: 0025-5408

Abstract

Highlights: Epoxy/BaTiO3 nanodielectrics developed for capacitive electrical energy storage. Three dielectric processes were observed, α-/β-modes and interfacial polarization. The charge transport properties were examined in ac and dc conditions. The energy density increased and tanδ decreased with increasing filler content. Abstract: Epoxy/BaTiO3 nanocomposites developed at low nanofiller concentrations with their dielectric relaxations, charge transport dynamics and capacitive energy storage were investigated via dielectric spectroscopy and dc charge-discharge experiments. Two relaxation processes were observed, namely the α- and β-relaxations, attributed to the dynamic Tg process and local motions, respectively. Another process located at low frequencies and high temperatures was identified as interfacial polarization. The charge transport properties were examined via the ac conductivity and impedance formalisms, indicating a beneficial effect with the increase of the nanofiller content. The dc conductivity was calculated from the ac spectra and exhibited Arrhenius temperature dependence. The theoretical energy density was found to increase up to 3.5 times comparing to the neat epoxy resin, highlighting the reinforcing dielectric/capacitive effect of the BaTiO3 nanoparticles on the epoxy resin. Comparisons between the theoretical energy densities and experimentally determined values were also discussed in detail. Graphical abstract: Image, graphical abstract