Cross-linked carbon networks constructed from N-doped nanosheets with enhanced performance for supercapacitors

Abstract Hierarchically porous carbons offer great benefits for constructing advanced electrodes for energy-related applications. Herein, we reported facile synthesis of cross-linked carbon networks (HPCNs) made from N-doped nanosheets. By using MgO as self-sacrificial templates, the polyethylene glycol and melamine precursors were first uniformly coated on the template, and then annealed at the elevated temperature in inert atmosphere before removing the templates by mild acid etching. Interestingly, the capacitance performance of HPCNs could be easily modulated by adjusting the mass ratio of the precursors and templates, as well as the carbonization temperature. The optimized HPCNs showed specific capacitances of 192.6 F g −1 at 1.0 A g −1 and 156.2 F g −1 even at 20 A g −1 in 6.0 M KOH solution, and long-term cyclability with 85.5% capacitance retention at high current load of 10 A g −1 after 8000 successive cycles, which were attributed to structural merits of these continuous networks including high surface area of 370.8 m 2 g −1 , high pore volume of 1.65 cm 3 g −1 , as well as high nitrogen content of 9.920 wt.%. Owing to simplicity of the synthesis method and superior performance, such HPCNs may promise great potential in energy storage fields.