• N-doping introduces defects that alter the electronic structure and electrochemical activity of carbon materials, enhancing their suitability for high-performance applications.
• Various preparation methods, including in-situ techniques (direct pyrolysis, CVD, solvothermal, arc discharge) and post-treatment processes (heat treatment, plasma, ball-milling, chemical oxidation), enable tunable N content and configuration.
• N content and configuration critically influence crystallinity, electronic conductivity, wettability, and chemical reactivity, which in turn determine sodium storage performance.
• The review provides a comprehensive framework for optimizing N-doped carbon materials for sodium-ion batteries, highlighting current challenges and future research directions.