MOF-derived nitrogen-doped porous carbon nanofibers with interconnected channels for high-stability Li/Na battery anodes.

Heteroatom-doped porous carbon materials have been widely used as anode materials for Li-ion and Na-ion batteries, however, improving the specific capacity and long-term cycling stability of ion batteries remains a major challenge. Here, we report a facile based metal-organic framework (MOFs) strategy to synthesize nitrogen-doped porous carbon nanofibers (NCNFs) with a large number of interconnected channels that can increase the contact area between the material and the electrolyte, shorten the diffusion distance between Li/Na and the electrolyte, and relieve the volume expansion of the electrode material during cycling; the doping of nitrogen atoms can improve the conductivity and increase the active sites of the carbon material, can also affect the microstructure and electron distribution of the electrode material, thereby improving the electrochemical performance of the material. As expected, the obtained NCNFs-800 exhibited excellent electrochemical performance with high reversible capacity (for Li battery anodes: 1237 mA h g at 100 mA g after 200 cycles, for Na battery anodes: 323 mA h g at 100 mA g after 150 cycles) and long-term cycling stability (for Li battery anodes: 635 mA h g at 2 A g after 5000 cycles, for Na battery anodes: 194 mA h g at 2 A g after 5000 cycles).