Electrostatic interaction in electrospun nanofibers: Double-layer carbon protection of CoFe2O4 nanosheets enabling ultralong-life and ultrahigh-rate lithium ion storage

We reported flexible N-doped carbon fiber/CoFe2O4 film with a double-layer carbon protection through electrospinning, showing a high reversible capacity of 858 mAh g−1 at 0.1 A g−1, ultrahigh rate capability (306 mAh g−1 at 30 A g−1), and superior cycling stability up to 10,000 cycles with almost no capacity loss at 10 A g−1.448