Graphitic carbon nitride film deposited with nitrogen-doped carbon nanoparticles as electrode for high-performance supercapacitors

Graphitic nitrogen-doped carbon film/nanoparticle composite, in which the films were wrapped and separated by the nanoparticles, was prepared through a simple co-calcination route. Due to its unique porous structure and improved nitrogen content, the as-prepared electrode material could exhibit high specific capacitances of 317.5 F g⁻¹ at 0.5 A g⁻¹ and 200.0 F g⁻¹ at 20 A g⁻¹, and stable cycling behavior with no capacitance decline after 10,000 cycles in three-electrode system. When assembled in two-electrode capacitor, its specific capacitance could be well kept at 265.5 F g⁻¹ at 0.5 A g⁻¹, and thus the supercapacitor with a high energy density of 9.22 Wh kg⁻¹ was obtained. The superior energy storage properties of the as-prepared material indicate its promising application as high-performance carbon-based electrode for supercapacitors.