Flexible CoFe2O4 nanoparticles/N-doped carbon nanofibers membrane as self-standing anode for lithium-ion batteries

The development of new generation wearable electronic devices requires the power supply with high power density, long-term cycling performance, and excellent flexibility and mechanical stability that would enhance the durability of flexible devices during use. Herein, we designed a novel strategy for the preparation of flexible self-supporting nanofiber membrane with highly dispersed CoFe ₂O ₄ nanoparticles embedded in one-dimensional (1D) N-doped carbon nanofibers (denoted as CFO@NCFM) by electrospinning and subsequent thermal treatment process, which possesses unique hierarchical structure containing zero-dimensional CFO@onion-like carbon nanospheres and cross-linked three-dimensional (3D) fiber network. The rational combination of the nano-sized CFO particles with high theoretical capacity and a N-doped carbon nanofiber conductive skeleton with interconnected 3D open microstructure facilitates the robust penetration of electrolyte into the electrode, improves the overall electrical conductivity of the electrode, shortens the diffusion pathways of Li ⁺ ions, and buffers the volume change of active materials during lithiation/delithiation. As a consequence, the optimized CFO@NCFM exhibits relatively high electrochemical reversible capacity (611.4 mA h g ⁻¹ at 100 mA g ⁻¹ after 100 cycles) and good cycling stability, as well as satisfactory rate capability.