Controlling the Precursor Ratio to Optimize Nitrogen Configuration: Enabling High-Performance Sodium-Ion Batteries through Nitrogen-Doped Graphene Aerogels

Sodium-ion batteries are promising for large-scale energy storage owing to abundant resources and low cost. However, the structure-performance relationship of nitrogen-doped carbon anodes still lacks clear understanding. Herein, nitrogen-doped graphene aerogels were fabricated via hydrothermal assembly and pyrolysis at 700 °C using melamine as the nitrogen source. The effects of GO-to-melamine ratio on microstructure, nitrogen configurations and sodium storage were investigated. The optimized G-M-3 sample (GO:melamine = 1:3) shows high graphite N and pyridinic N contents, enlarged interlayer spacing and a well-developed sp 2 carbon network. It delivers a high reversible capacity of 322.6 mAh g -1 at 30 mA g -1 , with 62% capacity retention after 100 cycles and 71.9% retention at 2000 mA g -1 . This work reveals the key relationship between precursor ratio, nitrogen doping and electrochemical performance, providing guidance for designing high-performance carbon anodes for sodium-ion batteries.