Design of hierarchical porous carbon nanofibrous membrane for better electrochemical performance in solid-state flexible supercapacitors

Abstract

The pore structure dramatically influences the electrochemical behavior of carbon nanofibers. The electrochemical performance of flexible carbon nanofibers as electrode materials for supercapacitors can be controlled by changing the size and quantity of pores. Hollow porous carbon nanofibers (HPCNFs) are prepared by coaxial electrostatic spinning and high-temperature carbonization. According to the nitrogen adsorption/desorption curve, HPCNF has a large specific surface area and good pore size distribution. In addition, cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) are used to analyze the electrochemical performance of HPCNF. Results show that the specific capacitance of hollow porous carbon nanofibers is 168.8 F/g at the current density of 1 A/g. Moreover, the specific capacitance retention of HPCNF is 95.61 % after 2000 cycles of charge and discharge at the current density of 5 A/g, exhibiting a stable cycle performance. In addition, solid-state supercapacitors assembled without any adhesives or conductive agents also show good cycle stability and excellent flexibility. As a result, HPCNF with flexibility, high specific surface area, and excellent electrochemical performance has broad prospects as an excellent electrode material for supercapacitors. Therefore, HPCNF has the advantages of good flexibility, high specific surface area, and excellent electrochemical performance. This paper proposes reasonable methods and creates more possibilities for future research and the application of flexible electrode materials for supercapacitors and flexible wearable electronic devices. • Different levels of hierarchical porous carbon nanofibrous membranes are constructed. • The effect of pores in carbon nanofibers on electrochemical performance are deeply studied. • Symmetric solid-state supercapacitors exhibit excellent stability and flexibility. • The charge distribution in supercapacitor are simulated by finite element method.