This chapter provides a comprehensive overview of the diverse applications of N-G materials in symmetric electric double layer capacitors, polymer based Pseudocapacitors, hybrid and asymmetric systems, and flexible or solid-state configurations. Nitrogen doping modifies graphene’s electronic structure, enhances surface polarity, and introduces various active sites that improve both double layer capacitance and pseudocapacitive behaviour. In symmetric EDLCs, N-G significantly increases specific capacitance and cycle life, while in polymer composites it serves as a conductive scaffold that strengthens structural integrity and suppresses degradation. When integrated with transition metal oxides, sulfides, or hydroxides, N-G enables hybrid electrodes with superior redox activity and mechanical robustness. Its adaptability also extends to flexible and microscale devices, where it maintains high electrochemical performance under mechanical deformation, making it ideal for wearable and portable energy systems. Asymmetric and hybrid configurations employing N-G as a stable negative electrode achieve wider voltage windows and higher energy densities. Furthermore, co doped N-G materials incorporating sulfur, boron, or phosphorus provide additional enhancements in wettability, stability, and redox contribution. Three-dimensional N-G aerogels, foams, and hydrogels further improve ion accessibility and conductivity, highlighting the importance of hierarchical design. Collectively, these developments establish N-G as a universal and tunable material platform for high performance, durable, and scalable supercapacitor technologies.