Nitrogen-doped porous carbon derived from bimetallic zeolitic imidazolate frameworks for electrochemical Li+/Na+ storage

摘要

Porous carbon is regarded as one of the most promising anode candidates for Li-ion battery and Na-ion battery, and the specific porous structure and heteroatom doping within porous carbon play a key role in the electrochemical performance. We herein demonstrate a series of nitrogen-doped porous carbon (NPC) by simply carbonizing bimetallic ZnCo-containing zeolitic imidazolate frameworks (ZnCo-ZIFs). The nitrogen content, specific surface area, and microstructure of prepared NPCs are balanced by adjusting the Zn2+/Co2+ molar ratio of ZnCo-ZIFs and carbonization process parameters. The optimized NPC derived from ZnCo-ZIFs delivers high specific capacity of 876.5 and 352.6 mA h g(-1) for Li+ storage at 0.1 and 5 A g(-1), respectively. After repeating 500 cycles at a high current density of 1 A g(-1), it almost has no capacity loss. In addition, the electrode also shows a great promise for Na+ storage. The excellent electrochemical Li+/Na+ storage performances could be attributed to the hierarchical porous structure, large specific surface area, and relatively high N-doping content.

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