Advances in nitrogen-doped carbon dots for electrochemical energy storage: from synthesis to applications

Abstract

Nitrogen-doped carbon dots (N-CDs) have emerged as a transformative class of carbon-based nanomaterials for next-generation electrochemical energy storage systems, owing to their outstanding electrical conductivity, tunable surface functionalities, and superior chemical stability. This review systematically explores recent advances in the synthesis of N-CDs, structural engineering strategies, and advanced characterization techniques, with an emphasis on structure–property relationships. Applications in lithium/sodium/potassium-ion batteries, supercapacitors, and metal–air batteries are critically assessed, with a focus on how nitrogen doping enhances charge transport, cycling stability, and energy density. The synergistic integration of N-CDs with metal oxides, conductive polymers, and hybrid nanostructures is also discussed as a pathway to overcome limitations of conventional electrode materials. Key challenges, including scalability, long-term cycling performance, and commercial viability, are analyzed. Finally, we highlight future research directions, including AI-guided material discovery, multifunctional composites, and eco-friendly synthesis approaches, providing a strategic roadmap for developing sustainable, high-performance energy storage technologies through the rational design of N-CD-based materials.