Enhanced surface capacitive sodium storage by pores regulation in carbon/carbon composite nanofibers

Carbon materials have broad application prospects as an anode material in the field of sodium-ion batteries (SIBs). Optimizing the structure of carbon materials has a significant effect in obtaining high electrochemical performance. Herein, carbon/carbon composite nanofibers (C/CNFs) were fabricated by electrospinning and their microstructure, texture, and surface functional groups are adjusted through introducing nanocarbons. The results show the introduction of graphene will regulate pore structures and surface functional groups, exhibiting excellent sodium storage performance as SIBs anodes. The graphene/carbon composite nanofibers (G/CNFs) showed a good reversible capacity of 253.6 mA h g−1 at 0.05 A g−1 after 300 cycles, which is enhanced by 62.67% comparing to the CNFs. The G/CNFs also retained a capacity of 200.6 mA h g−1 at 2 A g−1 after 600 cycles The pseudo-capacitive contribution was 90.4% at 1.0 mV s−1 for the G/CNFs. Regulating pore structure of carbon materials by other nanocarbons provided new reference for the application of energy storage but not limited to this. [Display omitted] •The pores in C/CNFs are regulated by introducing of nanocarbons.•The oxygen/nitrogen containing functional groups can be adjusted on the porous C/CNFs.•The pseudo-capacitive dominated C/CNFs modified by graphene showed best sodium storage performance.