Spiral semi-graphitic nitrogen-doped carbon anode for fast charging lithium-ion batteries

Studies of graphite carbon anodes due to their well-defined voltage plateaus at low potentials (0.2 V vs Li/Li⁺) and relatively high initial Coulombic Efficiency (CE) for lithium-ion batteries (LIBs) are an active area of research. However, the sluggish kinetics of lithium intercalation into conventional graphite anodes leads to metallic lithium plating phenomenon. Herein, the semi-graphitic nitrogen-doped carbon (SGNC) via one-step catalytic carbonization of cocoon silk was proposed to address the above challenges. By doping spiral semi-graphitic carbon materials with nitrogen, the SGNC exhibits an insertion peak of graphite carbon below 0.2 V, as well as an adsorption peak for lithium storage between 0.2 and 3.0V in hard carbon. The optimized nitrogen-doped spiral-like carbon shows an absorption-insertion lithium storage mechanism. As a result, the SGNC anode demonstrates high initial capacity (782 mAh g⁻¹ at 500 mA g⁻¹ and maintained 915 mAh g⁻¹ even after 1200 cycles) and good rate performance. The combined N-doping and nanopore defects in the spiral semi-graphitic carbon can significantly enhance the binding ability for Li-ions, charge transfer ability, and thereby improve the charge transport kinetics of the SGNC, resulting in improved rate capability.