Molten salt template-assisted synthesis of N, S-codoped hierarchically porous carbon nanosheets for efficient energy storage

To enrich the type of carbons for double-layer supercapacitors and optimize their electrochemical performances, N/S co-doped hierarchical porous carbons (KISPCs) with well-balanced pore characteristic have been prepared by taking ginkgo leaf as carbon source and KCl/K2CO3 molten-salt as template/activation agent. The as-obtained carbons possess a well-developed interconnected sheet-like structure, accompanying with high N, S and O contents, conductive to abundant ions transport channels and exposure of more ions-accessible active sites. Moreover, the types and contents of surface functional groups of hierarchical porous carbon could also be adjusted by K2CO3 content. A symmetrical supercapacitor was assembled to validate its electrochemical performance. The KISPCs electrodes manifest a specific capacitance of 215.2 F g(-1) at 0.05 A g(-1), splendid capacitance retention of 78.9 % (169.8 F g(-1) at 20 A g(-1)) and exceptional cycling stability with only 1.6 % capacity decay after 10000 charge/discharge cycles. This work can afford promising new tactics for the preparation of hierarchical porous carbon nanosheets and offer insights into the application of energy storage fields.

Automated summary

In this study, N/S co-doped hierarchical porous carbons were prepared using a novel method and exhibited excellent electrochemical performance in double-layer supercapacitors. The obtained carbons showed well-developed structure and composition, facilitating charge transport and exposure of surface active sites.