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

School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan, Anhui, China

^* Corresponding author: xjhe@ahut.edu.cn

Abstract

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 KHCO₃ activation strategy. The sample obtained at 800°C (S-HPC₈₀₀) possesses 3D framework structure with hierarchical pores, large specific surface area (1485 m² g^-1) and O, S-containing functional groups. Due to these synergistic characteristics, SHPC₈₀₀ 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.