Green Synthesis of Hierarchically Porous Carbon Derived from Coal Tar Pitch for Enhanced Lithium Storage

Abstract

Coal tar pitch (CTP) is a high-quality raw material for producing functional carbon materials owing to its high carbon yield and high degree of condensation. The rational structure regulation of CTP-derived carbon materials is paramount for their special application. Herein, a green template strategy is proposed to fabricate hierarchically porous carbon (HPC) and employ it as the anode material for lithium-ion batteries. It can be demonstrated that the mass ratio of the template (KHCO3) and carbon source (CTP) significantly influences the microstructure and electrochemical performances of HPC. HPC-3 synthesized by a mass ratio of 3:1 shows a coral-like lamellar nanostructure with high specific surface area, developed nanopores, and ample defects, enabling fast and high-flux lithium storage. Thus, the HPC-3 electrode achieves an excellent rate capacity of 219 mAh g−1 at 10 A g−1 and maintains a high discharge capacity of 660 mAh g−1 after 1400 cycles at 1 A g−1. This work takes a step towards the high-value-added and green utilization of CTP and offers a promising solution for the sustainable production of advanced carbon electrode materials.