Mechanochemical constructing quasi-pyridinic nitrogen/sulfur co-doped γ-graphyne for promoting lithium storage

Elemental engineering has been employed to adjust molecular framework and electronic configuration of γ-graphyne for rapid lithium storage. Here, we construct a quasi-pyridinic nitrogen/sulfur co-doped γ-graphyne (N/S-GY) via a mechanochemical strategy and reveal its lithium storage behavior by quantitative kinetics analysis and theoretical calculations. The internal pyridinic-N atoms create rhombic channels for Li + passing through, while sulfur dopants anchored with alkynyl groups induce electron cloud rearrangement to facilitate intralayer Li + diffuse between C 12 -triangular channels and interlayer transfer through open rhombic channels. As a result, the as-prepared N/S-GY exhibits a high reversible capacity of 1003 mAh g −1 at 50 mA g −1 after 150 cycles, with Li + diffusion coefficient up to 2.6 × 10 −12  cm 2  s −1 , both of which are larger than that of N-doped γ-graphyne. This work highlights synergistic effect of sulfur and nitrogen co-doping in alkynyl carbon and inspires bottom-up heteroatom modification in framework design.