Fabrication of porous carbon nanofibers by electrospinning as free-standing anodes for lithium-ion batteries

Free-standing anodes composed of porous carbon nanofibers (PCNFs) were fabricated by electrospinning for use in lithium-ion batteries. The use of terephthalic acid (PTA) as the sublimating agent, one-step carbonization at 900 °C for 2 h under vacuum converts the as-prepared samples to have interconnected pores along the PCNFs interior with numerous surface openings. The electrode was characterized using scanning electron microscopy (SEM), surface area analysis (BET), x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and Raman spectra (Raman). This strategy makes the PCNFs with a specific surface area of up to 290 m² g⁻¹, which is significantly higher than the CNFs with 107 m² g⁻¹. As a result, electrochemical tests exhibited that the PCNFs have a high discharge capacity of 750 mAh g⁻¹, which is sharply higher than that of the CNFs (234 mAh g⁻¹) at 100 mA g⁻¹. Even at a current density of 3000 mA g⁻¹, the PCNFs still exhibit a very high discharge capacity of 621 mAh g⁻¹. The present study may provide an effective strategy for synthesizing low-cost, binder-free, and environmentally friendly anodes for lithium-ion batteries with outstanding properties.