Core–Sheath\nPorous Polyaniline Nanorods/Graphene\nFiber-Shaped Supercapacitors with High Specific Capacitance and Rate\nCapability

Abstract

Fiber\nand/or yarn-shaped supercapacitors (FSSCs) have tremendous\npotential applications in portable and wearable electronics because\nof their light weight, good flexibility, and weavability. However,\nFSSCs usually show low energy density, which hinders their wide applications\nin wearable electronics. It remains challenging for the FSSCs to enhance\ntheir energy densities without sacrificing the flexibility and mechanical\nproperties. Herein, we develop a chemical polymerization strategy\nto fabricate core–sheath porous polyaniline nanorods/graphene\nfibers which are used as the FSSCs electrode and show excellent electrochemical\nperformances. The assembled polyaniline nanorods/graphene FSSCs exhibit\nan ultrahigh capacitance of 357.1 mF/cm², a high energy\ndensity of 7.93 μWh/cm² (5.7 mWh/cm³),\nand a power density of 0.23 mW/cm² (167.7 mW/cm³). In addition, the FSSCs show ultralong cycling life (3.8% capacitance\nloss, 5000 charge–discharge tests), good rate capability (78.9%\ncapacitance retention), and flexibility. The electrochemical performance\nof polyaniline nanorods/graphene FSSCs exceeds most reported hybrid\nFSSCs containing conducting polymers and/or metal oxide. This work\nmay pave the way in structure design for portable and wearable energy\nstorage devices.