Thin-walled hollow fibers for flexible high energy density fiber-shaped supercapacitors

Fiber-shaped supercapacitors, which occupy minimal volume and possess remarkable flexibility, are particularly promising candidates for next-generation smart wearable devices. However, the state-of-the-art energy density and mechanical properties of fiber-shaped electrodes are far from satisfactory. Herein, hollow poly(3,4-ethylenedioxythiophene):polystyrene sulfonate thin-walled fibers (HPFs) are continuously prepared by coaxial wet-spinning. These HPFs combine a simple and high continuous preparation with high electrochemical performance and flexibility, owing to their hollow nature, small diameter (125 mu m) and thin wall structure (8 mu m). As a result, the HPFs display a specific areal capacitance of 115.2 mF cm(-2) at a current density of 0.3 mA cm(-2) with a high energy density of 9 mu Wh cm(-2) at a power density of 0.112 mW cm(-2). Furthermore, the HPFs maintain 81% of the initial capacitance after 10,000 cycles with similar to 100% Coulombic efficiency. More importantly, the specific capacitance is almost completely maintained after bending 3000 times at 180 degrees.

Automated summary

The article introduces hollow poly(3,4-ethylenedioxythiophene):polystyrene sulfonate thin-walled fibers (HPFs) prepared by coaxial wet-spinning, which exhibit high electrochemical performance and flexibility, showing good specific areal capacitance, high energy density, and excellent cycling stability.