Simultaneously achieving high discharge energy density and discharge efficiency in P(VDF-CTFE)/PVDF based nanocomposites through topological-structure design and proper doping composition modulation

Abstract

The urgent demand of efficient power sources for microelectronics has stimulated the exploration of light-weight electrostatic capacitors with high energy density. With the distinctive characteristics of high dielectric constant and breakdown strength, Poly(vinylidene fluoride) (PVDF) based ferroelectric polymers have emerged as promising candidates for high-performance dielectric capacitors. However, the intrinsic high hysteresis loss of PVDF based polymers would largely weaken the discharge efficiency of capacitors, hindering their practical application. In this work, we demonstrate that through topological-structure design and proper doping composition modulation involving in MXene and boron nitride nanosheets (BNNS), considerable enhanced discharge efficiency and discharge energy density can be simultaneously achieved. For example, a 7 layered composite comprised of alternative BNNS reinforced layers and MXene reinforced layer presents an ultra-high discharge density and charge-discharge efficiency of 34.6 J/cm3 and 62 %, respectively. It is anticipated that this work will open a new design paradigm to direct PVDF based ferroelectric polymers towards viable high-performance capacitors.