Nitrogen-doped three-dimensional (3D) graphene foam (GF) has aroused tremendous interest for the supercapacitors (SCs) applications because of its unique properties. However, it is still confronting the challenges of facile preparation and the high N-doping level. Here, by rolling a part of graphene planes into the fiber-like scaffold to support other graphene sheets, we obtain high-quality 3D GF. Followed by fluorination and N-doping, N-superdoped GF (NGF) with N content as high as 15.7 at.% was successfully prepared. The combination of fiber-supported 3D structure and high N-level facilitate forming GF with large surface area, low internal resistance, good wettability, and sufficient active sites, which results in high-performance SCs: The prepared NGF electrode has a high specific capacitance (320.0 F g −1 and 303.5 F g −1 in three- and two-electrode system, respectively), and a long cycle life (92.8% retention after 1000 cycles), as well, the NGF SC device has a high energy density (42.1 Wh kg −1 at 250 W kg −1 ).

中文翻译：

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用于超级电容器的氮超掺杂和石墨烯纤维支撑的三维石墨烯泡沫的合成

掺氮三维 (3D) 石墨烯泡沫 (GF) 因其独特的性能而引起了超级电容器 (SC) 应用的极大兴趣。然而，它仍然面临着容易制备和高 N 掺杂水平的挑战。在这里，通过将一部分石墨烯平面卷入纤维状支架以支撑其他石墨烯片，我们获得了高质量的 3D GF。随后通过氟化和 N 掺杂，成功制备了 N 含量高达 15.7 at.% 的 N 超掺杂 GF（NGF）。纤维支撑的 3D 结构和高 N 级的结合有助于形成具有大表面积、低内阻、良好润湿性和足够活性位点的 GF，从而产生高性能的 SC：制备的 NGF 电极具有高比电容(320.0 F g -1 和 303。