Energy storage systems, including lithium‐/sodium‐ion batteries (LIBs/SIBs), are important for being able to use renewable energies efficiently. The anode material is a vital link in the great industrialization chain. Herein, a sandwich‐like N‐doped porous carbon/graphene (N‐HCG) composite has been successfully achieved by using a facile and low‐temperature liquid‐phase method with melamine as the nitrogen source, followed by a carbonization process. The composite possesses a high specific surface area of 282.4 m² g⁻¹. As an anode in lithium‐ion batteries, N‐HCG delivers a capacity of 643 mAh g⁻¹ at 100 mA g⁻¹, and a high capacity of 406 mAh g⁻¹ is maintained even at 5 A g⁻¹ after 2700 cycles. For sodium‐ion batteries, the obtained capacities of the N‐HCG electrodes are 208 mAh g⁻¹ (100 mA g⁻¹ for 120 cycles) and 145 mAh g⁻¹ (1000 mA g⁻¹ for 700 cycles). The excellent electrochemical performance including the rate capability and lifespan of N‐HCG can be attributed to the synergistic effects of the 2D sandwich‐like nanosheets with pores and extrinsic nitrogen doping. Thus, the as‐prepared N‐HCG composite is a highly promising anode material for LIB/SIB applications.

中文翻译：

---

N掺杂的多孔碳/石墨烯复合材料的类似三明治的纳米片，具有增强的锂和钠存储电化学性能

包括锂/钠离子电池（LIB / SIB）在内的储能系统对于能够有效利用可再生能源至关重要。阳极材料是巨大的产业化链中至关重要的一环。在此，通过使用以三聚氰胺为氮源的简便且低温液相方法，然后进行碳化过程，已成功实现了三明治状的N掺杂多孔碳/石墨烯（N-HCG）复合材料。该复合材料具有282.4m ²  g ^-1的高比表面积。作为锂离子电池的负极，N-HCG在100 mA g ^-1时可提供643 mAh g ^-1的容量，即使在5 A g ^-1时也可保持406 mAh g ^-1的高容量。2700个周期后。对于钠离子电池，获得的N-HCG电极容量为208 mAh g ^-1（120个循环为100 mA g ^-1）和145 mAh g ^-1（700循环为1000 mA g ^-1）。优异的电化学性能，包括N‐HCG的速率能力和寿命，可以归因于具有孔和外部氮掺杂的2D三明治状纳米片的协同效应。因此，所制备的N-HCG复合材料是用于LIB / SIB应用的极有希望的阳极材料。