Ultra-high discharged energy density capacitor using high aspect ratio Na_0.5Bi_0.5TiO₃ nanofibers

Abstract

An ultra-high discharged energy density P(VDF-HFP) capacitor is achieved by introducing a small fraction of Na0.5Bi0.5TiO3 nanofibers.

Ultrahigh Discharge Efficiency and High Energy Density in Sandwich Structure K0.5Na0.5NbO3 Nanofibers/Poly(vinylidene fluoride) Composites

“…Therefore, in order to obtain high U e , it is necessary to optimize E b and P max . [ 17–20 ] However, the most advanced commercial dielectric polymer biaxially oriented polypropylene (BOPP), due to its low dielectric constant, has a relatively low U e (≈3 J cm −3 ) even though it has a high E b . [ 21 ] Therefore, polymer composites have received great attention, and it is a common solving solution that inorganic materials with high dielectric properties and polymer matrix with high E b will be combined to obtain composites with excellent energy storage properties.…”

High Energy Density Dielectrics Based on PVDF‐Based Polymers

“…In dielectric nanocomposites, fibrous nanofillers are often used. The aspect ratio and the orientation of the nanofibers are important parameters that can greatly affect energy storage performance of the composites. Oxides with high dielectric permittivity are often used in those nanocomposites and when an electric field is applied to the composites, the electric field will be concentrated in polymer matrix of low dielectric permittivity.…”

“…On the other hand, to improve the dielectric properties, the 0‐3 composites of PVDF‐based polymers and ferroelectric oxide nanoparticles, which have much higher dielectric properties than normal dielectrics, have been intensively studied. These oxides include BaTiO 3 , Pb(Zr,Ti)O 3 , PMN‐PT, Na 1/2 Bi 1/2 TiO 3 , etc. Because the dielectric permittivity of PVDF‐based polymers is typically around two orders of magnitude lower than that of ferroelectric oxides, the applied electric field on the nanocomposites could concentrate in the polymers, resulting in a lower breakdown field.…”

“…Because the dielectric permittivity of PVDF‐based polymers is typically around two orders of magnitude lower than that of ferroelectric oxides, the applied electric field on the nanocomposites could concentrate in the polymers, resulting in a lower breakdown field. Compared with nanoparticles, nanofibers, and nanorods, with preferable orientation can mitigate the field‐concentration issue in the composites. Therefore, the nanocomposites with 1‐3 connectivity have also been intensively investigated in recent years .…”

Interfacial Coupling Effect in Organic/Inorganic Nanocomposites with High Energy Density

“…However, it is a challenge to achieve uniform nanofiller dispersion and small electric field distortion to enhance the ε r without sacrificing E b . In some methods (ex situ methods), small‐molecule ligands are used to tailor filler surfaces to improve compatibility with host polymers, consequently improving the apparent dielectric performance of the nanocomposites. There are two benefits of this type of approach: (i) uniform filler dispersion would minimize the local field distortion at the interface induced by the large dielectric contrast; and (ii) elimination of filler aggregation could avoid formation of microstructural defects (e.g., voids and flaws) at the interface.…”