Electrospun SiO2/C composite fibers as durable anode materials for lithium ion batteries

• Electrospun technique is employed to fabricate SiO2/C composite fibers.
• SiO2/C fibers are curved and have a reticular structure with large specific surface areas.
• SiO2/C fibers deliver a stable capacity at the current density of 50 mAh/g for 50 cycles.
• SiO2/C fibers display excellent rate-capability.

Electrospun together with thermal treatment is proposed to synthetize reticular amorphous SiO2/C composite fibers. The as-prepared fibers show carbon-coated SiO2 nanoparticles and form a space network structure, which cannot only improve the electrical conductivity, but also buffer the volume change. The SiO2/C fiber anode displays excellent performance, with an enhanced reversible capacity of 465 mAh/g at a current density of 50 mA/g up to 50 cycles, which is much higher than that of a pure SiO2 anode even at the first cycle (113.8 mAh/g). Favorable rate property (~ 240 mAh/g at a current density of 500 mA/g) also exhibits in the further electrochemical test. The excellent electrochemical properties are attributed to the carbon coat and the unique structure. These results suggest that the fiber materials can be used as an anode for rechargeable lithium-ion batteries.