Evolving Non-Aggregated ZIF-8 Nanoparticles into Hierarchically Porous Hollow Carbon Nanofibers for High-Performance Flexible Zinc-Ion Hybrid Supercapacitor

Zinc -ion hybrid supercapacitors are garnering widespread interest in wearable energy storage devices due to their high power density, intrinsic safety and cost-effectiveness. However, the primary obstacle to their progress lies in the scarcity of cathode materials that concurrently demonstrate excellent flexibility and high energy density. Herein, we deliberately design a coaxial electrospinning ZIF-8 derived hollow carbon nanofiber film electrode (C-PAN(ZIF-8)@PVP) to achieve high-performance flexible ZHSCs. The distinctive configuration of CPAN(ZIF-8)@PVP electrode comprises a shell of homogeneously distributed ZIF-8 derived porous carbon nanoparticles, which are bound together by N -doped carbon fibers derived from polyacrylonitrile (PAN), and a channel through the fiber created by the decomposition of polyvinylpyrrolidone (PVP). This unique architecture coupled with N, O co -doping bestows ample electrolyte infiltration, complete exposure of active sites, and a rapid pathway for electron conduction, resulting in facilitated ion diffusion kinetics, abundant active sites and enhanced electronic conductivity of the C-PAN(ZIF-8)@PVP electrode. As a result, the assembled ZHSC delivers a high reversible capacity of 116 mAh g-1 at 0.1 A g-1 and remarkable capacity retention of 100% over 4000 cycles at 5 A g-1. Moreover, it exhibits exceptional mechanical flexibility, capable of delivering stable output under arbitrary deformation. The intricate structural design strategy offers valuable insights for the development of high-performance electrode materials.