A nitrogen‐doped carbon layer coating on a 3D graphene framework (NCL@GF) was produced by the in‐situ polymerization of a uniform polyimide layer on the graphene framework surface and a carbonization process. The NCL@GF exhibited a 3D macroporous structure with uniform N‐doped porous carbon layers and a high 5.4 at. % nitrogen content, which not only effectively enhanced the active sites but also facilitated fast ion and electron transport in the 3D pathways. Consequently, the NCL@GF as the anode of a sodium‐ion battery (SIB) exhibited a discharge capacity of 357 mAh g⁻¹ at 0.1 A g⁻¹ after 200 cycles, a remarkable rate capability with a capacity of 122 mAh g⁻¹ at 8 A g⁻¹, and a super long cycle life with a capacity retention of 70 % capacity after 2500 cycles at 0.5 A g⁻¹. Such performance is superior to that of previously reported carbon or graphene‐based composites.

中文翻译：

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三维石墨烯基N掺杂碳复合材料作为钠离子电池的高性能阳极材料

通过在石墨烯骨架表面上均匀聚酰亚胺层的原位聚合和碳化过程，在3D石墨烯骨架（NCL @ GF）上形成了氮掺杂碳层涂层。NCL @ GF呈现3D大孔结构，具有均匀的N掺杂多孔碳层和高5.4 at。氮含量的百分比，不仅有效地增强了活性位，而且还促进了3D途径中离子和电子的快速迁移。因此，NCL @ GF作为钠离子电池的阳极（SIB）表现出的357毫安g的放电容量^-1在0.1 A克^-1 200次循环后，显着的速率能力具有122毫安g的容量^{- 1}在8 A g ^-1以及超长的循环寿命，在0.5 A g ^-1下2500次循环后容量保持70％。这种性能优于以前报道的碳或石墨烯基复合材料。