Boosting the electrochemical performance of carbon cloth negative electrodes by constructing hierarchically porous nitrogen-doped carbon nanofiber layers for all-solid-state asymmetric supercapacitors

Abstract

The electrochemical performance of carbon cloth directly relates to its surface area and porosity, and the functional groups of the primary carbon fibers. In this study, after rationally functionalizing a carbon cloth fiber surface with 3D porous nitrogen-doped carbon nanofiber layers, the resultant 3D hierarchical porous nitrogen-doped carbon nanofibers/carbon cloth negative electrode exhibits superior supercapacitive performance due to its large surface area, suitable porosity, nitrogen-doped carbon surface and fast electron transportation. This electrode delivers high areal capacitance of 608 mF cm⁻² at 1 mA cm⁻² and good cycle life (capacitance retention of 99% after the 5000th cycle). An asymmetric supercapacitor device is also assembled by using NiO@carbon nanofibers/carbon cloth as the positive electrode and nitrogen-doped carbon nanofibers/carbon cloth as the negative electrode, which exhibits high energy density of 19.5 W h kg⁻¹ at 4.1 kW kg⁻¹.