Low-Cost and N-Doped Porous Graphite Based on Coal Tar Pitch as High-Capacity Anode Materials for Lithium-Ion Batteries

Abstract

As one of the important anode materials for lithium ion batteries (LIBs), carbon materials have been widely studied and used because of their rich resources, low cost, and easy preparation. However, graphite, which is widely used at present, has low capacity and cannot meet the development needs of high energy density LIBs. Coal tar pitch (CTP), a low-cost industrial by-product, was used as the carbon resource to prepare N-doped porous carbon materials (PC), then the HCl solution and the NaOH solution are used to optimize the pore structure and surface functional groups. The influence mechanism of the HCl solution and the NaOH solution on the pore structure and functional groups of carbon materials has been revealed by FTIR, SAXS and other characterization methods. As an anode material for LIBs, it can show a high reversible capacity of 711.3 mAh/g after 100 cycles at a current of 0.1 A/g, and after 550 cycles at a current of 0.5 A/g, it can still retain a high capacity of 440.4 mAh/g. In addition, both as the anode materials of the full cell and sodium ion battery, the obtained PC materials show excellent cycle stability.

Keywords: Coal tar pitch, Porous carbon, High-capacity, Anode materials, Lithium ion battery