Si@SiOx/CNF Flexible Anode Prepared by Electrospinning for Li-Ion Batteries

Si@SiOx/CNF flexible composite films were prepared by electrospinning, oxidation stabilization and high-temperature pyrolysis. The composites’ physical properties and electrochemical performances were characterized in detail to clarify their structure, actual composition, and the influence of silicon on the capacity utilization rate and stability of the anode composites. The results show that the Si@SiOx particles are formed in oxidation process and embedded into the carbon fiber matrix to form a three-dimensional network structure. With the increase of nano-silicon content, the agglomeration of nano-silicon particles inside and on the surface of the fiber intensifies, and the specific capacity of the composite increases first and then decreases. When the content of nano-silicon is about 34.87 wt %, the theoretical specific capacity utilization rate of the composite is about 67.71%. Moreover, the three-dimensional flexible composite has a higher discharge specific capacity 1085 mA h/g after 100 cycles at 0.1 A/g and better cyclic stability.