Significantly promoting the energy storage performance of hierarchically porous carbon by introducing antimonene nanosheets

Abstract

• Preparing a new electrode material Sb@HPC by mixing HPC and antimonene. • The specific capacitance of the Sb@HPC is about 3 times that of HPC. • The introduction of antimonene does not sacrifice the rate performance of HPC. Increasing the capacitance and cycle life of electrode materials while maintaining a high rate in supercapacitors is still a challenge. Herein, we report a new electrode material Sb@HPC prepared by mixing hierarchically porous carbon (HPC) with a high specific surface area of 2810.1 m 2 g −1 and antimonene nanosheets. In a three-electrode system, the specific capacitance of the Sb@HPC (1138 F g −1 at 2 A g −1 ) is about 3 times that of HPC (420 F g −1 at 2 A g −1 ). Besides, when the current density increases from 2 to 10 A g −1 , the Sb@HPC delivers a high rate capability with 70.8 % initial capacitance retention, which is comparable with that of the HPC (70.0 %). Most importantly, the specific capacitance retention of the Sb@HPC can reach up to 100 % after the cyclic test at 10 A g −1 , which is much higher than that of the HPC (50 %). These results reveal the introduction of antimonene nanosheets improves the specific capacitance and cyclic performance of the HPC without the degradation of rate performance. This work provides a reference for the improvement of specific capacitance and cycle life of other electrode materials.