Construction of S-doped hierarchical porous carbons by acid-free treatment strategy for supercapacitors

摘要

The pollution from acid treatment process in the preparation process of hierarchical porous carbons is a substantial challenge for industrial application of supercapacitors (SCs), which necessitates the development of green alternative technologies. In this work, S-doped hierarchical porous carbons (S-HPCs) are prepared from cheap coal tar pitch by a less harmful in situ KHCO_(3)activation strategy. The sample obtained at 800°C (S-HPC_(800)) possesses 3D framework structure with hierarchical pores, large specific surface area (1485 m~(2)g~(-1)) and O, S-containing functional groups. Due to these synergistic characteristics, SHPC_(800)as supercapacitor electrode exhibits high specific capacitance of 246 F g~(-1)at 0.1 A g~(-1)with a capacitance retention of 68.3% at 40 A g~(-1)and excellent cycle stability with 96.7% capacitance retention after 10, 000 charge-discharge cycles. This work provides an environmentally friendly approach to prepare advanced carbon-based electrode materials from industrial by-products for energy storage devices.