N₄-Vacancy-Functionalized Carbon for High-Rate Li-Ion Storage

Although heteroatom doping and pore management separately influence the Li+ adsorption and Li+ diffusion properties, respectively, merging their functions into a single unit is intriguing and has not been fully investigated. Herein, we have successfully incorporated both heteroatom doping and pore management within the same functional unit of N4-vacancy motifs, which is realized via acid etching of formamide-derived Zn–N4-functionalized carbon materials (Zn1NC). The N4-vacancy-rich porous carbon (V-NC) renders multiple merits: (1) a high N content of 13.94 atom % for large Li-storage capacity, (2) edged unsaturated N sites favoring highly efficient Li+ adsorption and desolvation, and (3) a shortening of the Li+ diffusion length through N4 vacancy, thereby enhancing the Li-storage kinetics and high-rate performance. This work serves as an inspiration for the creation of heteroatom-edged porous structures with controllable pore sizes for high-rate alkali-ion battery applications.