A novel N-doped graphene-like carbon nanosheets (CNs) and carbon nanotubes (CNTs)-encapsulated Co-Co₃O₄ nanoparticles (NPs) (CN@Co-Co₃O₄/CNTs) were synthesized successfully by a simple hydrothermal and annealing method with graphite carbon nitride (g-C₃N₄) as self-template. By annealing Co²⁺/g-C₃N₄ under N₂ atmosphere, g-C₃N₄ was transformed into CN/CNTs, and Co²⁺ was reduced into CoNPs which were embedded in CNs. Further annealing in air, a shell of Co₃O₄ was formed around CoNPs. The amount of CNs, CNTs, and CoNPs can be adjusted by changing the ratio of Co²⁺ in Co²⁺/g-C₃N₄. The graphene-like CNs provided a large number of active sites and a large specific surface area for loading lots of small CoNPs uniformly. The CNTs with a diameter of 100 nm could not only improve the conductivity but also provide a buffer space for the aggregation and volume expansion of Co₃O₄. CNTs also enlarged the interlayer distance of CNs, which prevented the re-stacking of CNs and provided great convince for the intercalation and de-intercalation of Li⁺. When applied for anode material of lithium-ion batteries, CN@Co-Co₃O₄/CNTs exhibited a high discharge capacity of 460.0 mAh g⁻¹ at 5000 mA g⁻¹ after 300 cycles with a Coulombic efficiency of 98% and excellent higher-rate capacity (401.0 mAh g⁻¹ at 2000 mA g⁻¹ and 329.0 mAh g⁻¹ at 5000 mA g⁻¹).

通过简单的水热法成功地合成了新型的N掺杂石墨烯样碳纳米片（CNs）和碳纳米管（CNTs）包裹的Co-Co ₃ O ₄纳米颗粒（NPs）（CN @ Co-Co ₃ O ₄ / CNTs）。以石墨碳氮化物（gC ₃ N ₄）为模板的退火方法。通过在N ₂气氛下对Co ²⁺ / gC ₃ N ₄进行退火，将gC ₃ N ₄转化为CN / CNT，并将Co ²⁺还原为嵌入CNs的CoNPs。在空气中进一步退火，生成Co ₃的壳O ₄在CoNP周围形成。CNS中，碳纳米管，和CoNPs的量可以通过改变Co的比率来调节²⁺在钴²⁺ / GC ₃ Ñ ₄。石墨烯状的CNs提供了大量的活性位点和较大的比表面积，可均匀地装载许多小的CoNP。直径为100 nm的CNT不仅可以提高导电率，而且还为Co ₃ O ₄的聚集和体积膨胀提供了缓冲空间。碳纳米管还扩大了CNs的层间距离，从而阻止了CNs的重新堆叠，并为Li ⁺的嵌入和脱嵌提供了极大的说服力。。当用于锂离子电池的负极材料时，CN @ Co-Co ₃ O ₄ / CNT在300次循环后，在5000 mA g ^-1下表现出460.0 mAh g ^-1的高放电容量，库仑效率为98％，并且具有优异的库仑效率。较高速率容量（毫安401.0克^-1在2000毫安克^-1和329.0毫安克^-1在5000毫安克^-1）。