Oxygen-Doped Nanographene as High-Performance Anode Material in Lithium-Ion Batteries

We report the synthesis, structural characterization, and electrochemical evaluation of a novel oxygen-doped molecular nanographene (O-doped-NG) as a high-performance anode material for lithium-ion batteries (LIBs). Designed from an anthraquinone core, O-doped-NG was obtained via a three-step synthetic sequence, yielding a less-known π-extended nanographene with embedded oxygen-containing pyran units. Characterization via MALDI-ToF MS, solid-state NMR, FT-IR, Raman spectroscopy, and powder x-ray diffraction confirmed the formation of a highly conjugated, multilayered graphitic material with increased interlayer spacing and structural defects attributed to oxygen doping. Electrochemical testing demonstrated remarkable anode performance. Compared to its polyarene precursor, O-doped-NG showed a 2.7-fold increase in specific capacity, reaching up to 750 mAh/g at 0.1 A/g current density, outperforming graphite's theoretical limit. The material exhibited excellent rate capability, with 320 mAh/g retained at 2 A/g over 200 cycles, and outstanding cycling stability (>500 cycles) with minimal capacity loss. The synergistic effects of π-extension, oxygen doping, and molecular planarity contribute to enhanced lithium-ion diffusion, improved wettability, and stable charge transfer. This study highlights the promise of heteroatom-doped molecular nanographenes as sustainable, high-capacity anode materials for next-generation LIBs, offering new directions in the design of organic-based energy storage systems.