Improved Energy Storage Property of Sandwich-Structured Poly(vinylidene fluoride)-Based Composites by Introducing Na_0.5Bi_0.5TiO₃@TiO₂ Whiskers

Abstract

In recent years, high-energy-density polymer-based capacitors have received extensive attention because of their potential applications in advanced power systems and electronic equipment. However, their development is severely hampered by the inherent features of polymers such as low polarization and low charge–discharge efficiency (η). In this study, a new strategy for core–shell Na0.5Bi0.5TiO3(NBT)@TiO2(TO) whiskers combined with sandwich-structured poly­(vinylidene fluoride) (PVDF)-based dielectric composites is proposed, in which the middle layer is the PVDF-based composites filled with different fractions of NBT@TO whiskers and the outer layers are pristine PVDF. The experimental results show that the loading of NBT@TO whiskers can simultaneously optimize electrical displacement and breakdown strength of the sandwich-structured composite due to the additional interfacial polarization and the contribution of the barrier effect between adjacent layers. Thus, a significantly improved electric displacement of ∼13.99 μC cm–2, a maximum discharge energy density (U d) of ∼15.42 J cm–3 at a low electric field of 314 MV m–1, and a high charging–discharging efficiency (η ∼ 66.12%) can be obtained from the composite with the middle layer containing 6 wt % NBT@TO whiskers. This research provides a strategy for the preparation of advanced polymer-based composites with a superior discharge energy density in the future.

Superior capacitive performance achieved in wide HOMO–LUMO gap cyanoethyl cellulose nanocomposites via forming a built-in electric field

“…The 0.2 wt% BFO@AO composite film reported in this work exhibited a high U d of 31.3 J cm −3 , which is the best when compared to previous references. 13,34–36…”

“…The 0.2 wt% BFO@AO composite film reported in this work exhibited a high U d of 31.3 J cm À3 , which is the best when compared to previous references. 13,[34][35][36] Continuous and frequent charging and discharging processes will constantly generate heat, and the coupling effect of heat, electricity, and force seriously reduces the quality of the film, which is fatal to practical applications. Cyclic charge-discharge tests were performed to evaluate the reliability of the CRC-based nanocomposite films at 200 MV m À1 (Fig.…”

Improved energy storage performance of sandwich-structured P(VDF-HFP)-based nanocomposites by the addition of inorganic nanoparticles

“…8. 19,28,33,37,[39][40][41][42][43][44][45][46][47][48][49] It can be seen that the sandwich-structured 0-0.6-0 nanocomposite reported in this work not only has a higher E b (B565 MV m À1 ), but also has a higher U d (B21.39 J cm À3 ) and Z (B70.54%), showing significantly better properties than other multi-layer nanocomposites. The results show that sandwich-structured nanocomposites are a convenient strategy to enhance the energy storage performance of composites.…”

Improved energy storage properties of polypropylene-based composite dielectrics by introducing surface-charged BaTiO3@chitisan ultrafine constructions

“…10 (iv) The CS shell with moderate e r employed as a buffer layer can further reduce the e r -mismatch between BaTiO 3 and PP and alleviate the local electric field distortion at heterogeneous interfaces in composites. 22 (v) The positively charged CS shell exhibits an inherent high electron affinity, which introduces a number of charge traps into the composite dielectrics. These traps could capture free charges and suppress the fast development of an electrical tree, thus enhancing the E b of the composites.…”

“…[19][20][21] To deal with this problem, in recent decades, a number of composite dielectrics were prepared by incorporating various high-e r inorganic nanofillers into different polymer matrices, aiming to merge the superiorities of these different phases and to achieve synchronous improvement in both e r and E b in composite dielectrics. [22][23][24][25] However, due to the significant difference in e r between polymer matrices and high-e r ceramic fillers, the localized electric field at the heterogeneous interface would be re-distributed non-uniformly, resulting in the accumulation of charges at the interface and the occurrence of premature breakdown in composites. [26][27][28] In recent years, researchers have found that the dielectric properties of ceramic fillers are closely dependent on their crystal size.…”