Core–Shell Nanostructure Design in Polymer Nanocomposite Capacitors for Energy Storage Applications

Abstract

The ability to tune the interfacial layer in nanocomposites is attracting increasing interest due to its wide application in the field of nanoscale energy storage materials. However, most of the current interfacial modifiers are flexible coils collapsing on the surface of fillers. The interfacial layer thickness cannot be readily tailored. This work demonstrates an inspiring approach to design the interfacial layer of BaTiO3 nanowires and nanoparticles with poly{5-bis[(4-trifluoro-methoxyphenyl)oxycarbonyl]styrene} (PTFMPCS). The PTFMPCS is a kind of fluoric-liquid-crystalline polymer (LCPs) that possesses polymer-chain rigidity and an orientated structure, which is useful to design the interfacial layer thicknesses of fillers. Four types of BaTiO3@PTFMPCS nanostructures are prepared and incorporated into a polymer matrix for capacitor applications. The experimental results show that the PTFMPCS interfacial layer thicknesses are precisely controlled and in good agreement with the theoretically predicted thicknesses. In addition, the performance of the nanocomposites are obviously affected by the PTFMPCS interfacial layer thickness, e.g., the discharge energy density of the nanocomposites with a 14.8 nm thickness of the PTFMPCS layer increased by 8.5% than with 9.2 nm, which reaches to 14.64 J/cm3. The findings provide an innovative way to design the interfacial layer thickness in various nanostructured materials for applications related to energy storage.