Novel Fabrication Of N/S Co-doped Hierarchically Porous Carbon For Potassium-Ion Batteries

It has been demonstrated that embedding potassium ions into graphitic carbon is viable. However, the large ionic radius of potassium-ions is a severe obstacle of potassium-ion transmission between the cathode and anode. Therefore, it is urgent to find an electrode material with larger interlayer spacing to facilitate potassium-ion intercalation/deintercalation. Herein, hierarchically nitrogen and sulfur co-doped porous carbon (NSPC) have been prepared with sodium polyacrylate as the carbon precursor and sodium chloride as the template. When used as the anode materials for PIBs, NSPC shows reversible capacities of 289.7 mAh g(-1) after 70 cycles at 50 mA g(-1) and 156.8 mAh g(-1) after 1000 cycles at 500 mA g(-1). The high reversible capacity and excellent cyclic performance of NSPC can be ascribed to the three-dimensional structure with nitrogen and sulfur co-doping, which improves electronic conductivity and enlarged interlayer spacing, facilitating potassium-ion insertion. This work provides some insights into the fabrication of heteroatom-doped carbon materials and is helpful for the design of high-performance anode materials for PIBs.