3D Nitrogen-enriched graphene porous graphene hydrogel for high-performance supercapacitor

3D interconnected porous nitrogen-enriched graphene (NG) hydrogel was fabricated through ethanediamine as reducing and doping agent. The 3D porous structure of the NG enhances the accessibility to ion diffusion. Notably, when the NG material works as binder-free electrode, it achieves a high specific capacitance of 316.8 F g⁻¹ at 0.5 A g⁻¹. After the current density increased 40 folds, it still can reach 173.6 F g⁻¹. 54.8% of capacitance retention can be achieved after the current density increased by 40 folds. This study provides a scalable approach to prepare 3D porous NG hydrosgel. (paper)