Free-standing porous carbon nanofiber membranes obtained by one-step carbonization and activation for high-performance supercapacitors

Abstract

The capacitive performances of carbon materials greatly rely on the porous structure and conductive network. However, the compromise of carbon materials with suitable porosity and 3D conductive framework still exists difficulty. Herein, a hierarchical porous free-standing carbon nanofiber (CNF) membrane was obtained from electrospun cellulose acetate (CA) nanofiber membrane via one-step carbonization and activation process. The influence of carbonization temperature on microstructure and electrochemical performance of carbons are investigated. The 800 °C carbonized sample CA-CNFs-800 exhibits large specific surface area of 720.8 m2 g−1 and suitable pore size distribution. The micropore dominated structure and three-dimensional conductive carbon networks enable fast electron/ion transport. The specific capacitance reaches 229.4 F g−1 at 0.2 A g−1 with good rate performance of 72.8% capacitance retention at 20 A g−1 for CA-CNFs-800. Moreover, CA-CNFs-800 possess high capacitance retention of 97.3% after 40,000 cycles at 20 A g−1. The CA-CNFs outperform other bio-based carbon materials, highlighting the great promise of CA-based CNFs for improving the capacitive performance of supercapacitors in electronic energy storage devices.