Free-Standing Si@C/CNFs Prepared by Simple Electrospinning as a Stable Anode for Lithium-Ion Batteries

The development of free-standing and foldable electrodes with excellent electrochemical performance is paramount for flexible electronic devices. However, the silicon-based free-standing anodes lack a straightforward preparation process. Herein, we successfully designed a hierarchical Si@C/CNFs composite material by combining hydrothermal and electrospinning techniques, in which the carbon-coated silicon (Si@C) is served as the primary nanostructure and carbon nanofibers (CNFs) from electrospinning are maintained as the network matrix, resulting in a free-standing anode. Owing to the amorphous carbon coating on Si nanoparticles and the formation of a 3D network structure of CNFs, which tightly encases the primary Si@C nanostructure, the Si@C/CNFs electrode demonstrates exceptional conductivity and flexibility. This dual carbon-layer structure further enhances kinetics and mitigates the volume expansion of Si nanoparticles. The Si@C/CNFs electrode exhibits a high specific capacity (1573 mAh g-1 at 0.1 A g-1), exceptional rate capability, and excellent cycling stability (78.5 % capacity retention after 100 cycles). Thus, Si@C/CNFs can be a promising material for the anode electrode in flexible lithium-ion batteries. A free-standing and foldable electrode of Si@C/CNFs prepared by a combination of hydrothermal and electrospinning techniques, shows a high specific capacity (1573 mAh g-1 at 0.1 A g-1), exceptional rate capability, and excellent cycling stability (78.5 % retention after 100 cycles), making it a promising material for flexible lithium-ion batteries. image